How to maintain
and repair a boat:
tools, spares,
techniques, troubleshooting

    Impossible parts     Contact me.

This page updated: December 2011

Troubleshooting / Techniques

My Boat Engine Maintenance page
My Boat Fiberglass Maintenance page
My Boat Haulout page
My Boat Hull Blisters page
My Boat Painting page
My Climbing The Mast page
My Outboard Motor Maintenance page
My Sail Maintenance page

"If it doesn't move and it should, spray it with WD-40.
If it does move and it shouldn't, wrap it with duct tape."
- Jim and Tim, the Duck Tape Guys

"In theory, there is no difference between theory and practice.
But, in practice, there is."
- Jan L. A. van de Snepscheut, or maybe Chuck Reid ?


Good repair attitudes

Partly from "The Voyager's Handbook" by Beth Leonard:
  • Be prepared: tools, manuals, parts, knowledge.
  • Don't be afraid to tackle a job.
  • Check simplest things first. (A simple thing)
  • Take your time.
  • If you take something major apart, stay organized.
  • Don't be afraid to ask for help/advice.

From "Offshore Cruising Encyclopedia" by Steve and Linda Dashew:
Basic rules to apply to all repair jobs:
  • Don't be afraid to tackle the project.
  • Always look for a simple answer to a problem.
  • Take your time. [Study the problem, be methodical and systematic, consult manuals and books, don't get frustrated.]
  • Only start to disassemble something after all other avenues have been exhausted. [And do it slowly, labelling pieces, work over a good surface, store pieces carefully.]
  • Be very careful about forcing something that's stuck.

  • The majority of cruising repairs revolve around electrical problems. ... When a piece of electrical gear fails, the odds are there's a loose, wet, or dirty connection ...
  • Pumps seems to be more maintenance-prone than any other type of gear aboard.

SailNet - Don Casey's "Zen and the Art of Sailboat Maintenance"
SailNet - Kristin Sandvik's "The Best Maintenance is Use"
Chris Caswell's "Maintaining Fiberglass" (misleading title)
Boat Maintenance For (non) Idiots
Nancy Knudsen's "Boat maintenance tips for the frugal sailor"
Periodic Maintenance section of my Lists for Operating a Boat page

From unknown:
... one thing that I have seen get people into real trouble especially with starting experience as you have: maintenance, do EVERYTHING yourself. No no no. If you read boating mags you will CONSTANTLY see the editors advising, let someone else do this or that. There are many things you can do yourself, but some things that look simple are, but very dangerous if not done right. I have towed too many boats in to safety. ... I have just seen so many mishaps from sailboaters because of the cheap thing. It pays to be thrifty, but sometimes you absolutely get what you pay for. ...

> What kinds of work would you say should be done by experts, not the owner ?
> Are there some specific areas I should watch out for ?
> I have heard that some boatyard workers may be less competent than a knowledgeable,
> careful and motivated owner. And certainly if you've done the work yourself,
> you are in a better position to redo it or fix it at sea. But you're right;
> trying to do everything yourself probably is a mistake.

I totally agree, for many things, all the workers in the boatyards are not that competent. I probably would not align a shaft, etc myself. I would use a boatyard. For other things, there are usually many good independent people on the waterfront that are far better than the average guy in a boatyard. A boatyard could not keep my diesel guy for instance, and he can make it on his own. At the large marine mech. shop that everyone thinks is great, they use people and kids that are not as sharp or knowledgeable but they charge a fortune, but pay the worker not too much. I just saw a disaster on a boat where it was eaten alive. The owner trying to save money, installed the genset himself. Fine, right up to the time when he was asked why it was not grounded? He just had a blank look on his face. Now he has a bill and damage about ten times than he ever expected to pay for anything. I see problems by people buying cheap batteries. That's why cheap is dangerous sometimes. Maintenance is one thing, but I don't pretend to be a shipwright, so don't do anything out of a book that takes a shipwright, or at least let one inspect as the work is done, and things are still out in the open. Buy the best batteries, wire, electrical parts, rigging, line, chain, ANYTHING that takes a major load, or can cost your life. Cheap parts are cheap for a reason. The best tip I can give anyone is watch a commercial fisherman who depends on the boat for their living and LIFE. They don't buy anything but the best. Save money on something else. Buy strong and tough. You will be the one not calling mayday.

"In fact, most home projects are impossible, which is why you should do them yourself. There is no point in paying other people to screw things up when you can easily screw them up yourself for far less money."
-- Dave Barry, "The Taming of the Screw"

From Stuart Burgess:
If however this job [replacing gate-valves] is underway and you are in the boatyard I would recommend the following approach with new jobs.

Look at what has to be done. Read Nigel Calder's book on that job. 'Boat Owners etc' Can the layout, setup, location be improved? Ask, Can you do it yourself. If uncertain then get the guy from the yard to do the first one / first job and stand 2 inches away and get him to chat. He will tell you how to do it, the boatyard tricks that make the job easier ... and best of all, he will probably be interested in doing the job on the side at night, weekend etc, or he will know one of his mates who would like the job.

This is an art that took me a long time to learn. There are some jobs that the yard can do in a fraction of the time because of tools and experience. Most jobs however can be carried out by someone competent with knowledge. You are obviously competent but won't have the knowledge YET. So pay the minimum to get that part of the job done which will give you that knowledge. Next time you will be able to do it yourself.

I have spent the last two days sitting in my bilge. Under the bilge is a huge sump tank which is sealed in and takes all the grey water from the showers and basins. When this reaches a certain level it activates a switch which pumps it out through a fitting above the water line. It keeps the thru hulls to a minimum and is a good idea. But to get to this sump is a nightmare. The double bunk has to be stripped, the paneling removed, the heat exchanger/calorifier wires removed and then the calorifier lifted out with tubing attached ... and so it goes on, all to get to a stupid switch that has some gunge on its sensors. Yesterday I changed it for an air activated Par Hydro-air switch. No more bloody electrics in the gungy water.

The point is this ... a boat is made up of a large amount of complex systems. It will take you a couple of years to understand the systems and how they inter-relate. Yes, initially you will be overwhelmed especially as what appears to be a simple problem defies solutions. You have to stand back from it and be objective. You also must never lose sight of the fact that a 20ft boat is the same as a 44ft boat ... the only difference is scale. You need to take your time on each job. Do not bodge a part of a system but look at the whole system in relation to the boat. See what it's meant to do and figure out if there is an easier/better more efficient way of doing it. Do NOT be dismayed at the problems. The more problems there are the more you will learn about your boat.

Most importantly, leave time to use and enjoy her. Go for a sail. Anchor off and spend the summer using her. Fix things that break but don't make any big changes until Winter approaches. By then you will have a much better feel for her and the changes that you would like for your lifestyle. This also avoids spending money on replacing one part when you may want to change the whole system later on.

If your fuel tank or water tank etc has a leak. It doesn't mean that the boat is crap ... it just means the tank needs replacing or repairing.

Last weekend my freshwater system was playing up. It wouldn't pressurise and the system was full of air. Continually opening the taps to clear the air would sometimes work and sometimes didn't. There were no leaks and the tank was half full. The pump is working fine and drawing. This was a real head scratcher and is not an uncommon problem. On Wednesday after several hours I discovered the problem. It was a blocked air vent which allows the tank to breathe. Simple, but not obvious.

Because your boat has 4 bilge pumps or 20 thru hulls doesn't mean that you have to have them all working to be able to enjoy her. You only need one bilge pump operating ... the rest can wait. Don't lose sight of this.
More from Stuart Burgess:
... just read your updated log. Boats are fun, aren't they. Sounds to me that you are still very much overwhelmed. This is a natural consequence of having high standards for yourself and purchasing someone else's vessel where the standards have been a little different.

You are not going to be able to do everything at once.

It is going to take you 24 months to sort her out.

If you have one crappy chainplate, then there will be others, so don't rush to fix that one. There will be other jobs that require the removal of headlinings etc in the future and that is the time to fix these. You will also have made some contacts by then which will help with materials and workmanship.

e.g. stainless steel costs very little when purchased from a steel stockholder. You then find someone to shape it and learn to 'polish' it yourself.

Your thru hulls: Once you are out of the water you have to do what the yard will do. Remember they will just replace the thru hulls so don't mess about with heating etc to get them apart. Buy or hire a grinder and grind off one side or the other. Hey presto a nice clean hole and no crappy thru hull.

Don't lose sight of the fact that these guys in the yard are no different than you and I, they have just been doing it longer. They are not magicians and many of them make dumb mistakes. When you use the yard, work on the principle that you are hiring a teacher. Watch and learn and don't assume that what he is doing is always the best way of doing that particular task.

Last weekend I noticed that the sealant joint between my pilothouse and deck was pulling apart. On checking, it was being caused by the mizzen shrouds being far too tight and as their chainplates are on the pilothouse roof they were actually pulling the whole pilothouse skywards! This was rigging done by the guys who rig the Oysters! So pity the poor Oyster owners.

Don't try and do too much all at once. Concentrate on one task and do it properly.


From RadarLove on Cruising World message board:
The most important attribute a "cruiser"/wanderer/voyager can have is a willingness to tear into things that are broken and try to fix them. Handiness is not an inherited trait. If you start taking apart things that are broken and try to fix them, you will learn to use the tools, then you will find yourself buying tools and over time you will develop the trait of "handiness". Trust me, this works. Just start.

From Leander on Interview With A Cruiser project:
Most marine vendors do not share your goal of having quality work done at a reasonable price. Learn to do as much as possible on your boat, and be vigilant in those situations when you must pay for parts or services. Time and again we've paid for work that was both overpriced and deficient, and typically found we have no recourse after the fact. Who cares about you – you're sailing away to the next port! With a little bit of practice, reading, and speaking to others, you will ALWAYS do a better job than someone with less of a vested interest in the outcome. When others must be called in, define the scope of the work as concretely and narrowly as possible, get things in writing, and watch the work like a hawk.

Kit Stansley's "Six Questions to Ask Yourself Before You DIY"

Message I sent to Warren Carter:
> My main Q is -- Can the coastal cruising life be done economically ?
> Is there a boat that can take years of sailing with low maintenance ?
> Or are boats just holes in the water, that we must throw money into ? : )

I'm no expert, but here's my guess:

1- All boats live in a hostile environment. Some environments (e.g. fresh water, inland lakes) are less hostile than others.

2- You could reduce maintenance by not having equipment (KISS). The extreme example of this: live on a raft or something.

3- You could reduce maintenance by letting your boat decay, as long as it keeps floating, if that standard is acceptable to you.

4- You can reduce repairs by learning to use the boat properly and preventatively maintain it.

5- You can reduce the costs of maintenance by doing as much as possible yourself.

6- You can reduce the costs of maintenance by living in a labor-cheap area.

7- Some boats may be better constructed than others, and require less maintenance or repair. I suspect that except for fundamentals such as hull blistering, deck leaks and delamination, this is the least important factor.

From Steve Weinstein on The Live-Aboard List:
... You all know Boat Math, I assume. You start with a list of 10 projects, finish 8, and find yourself with only 15 projects left. Boat projects have a definite kinship with rabbits. ...

From George and Sonia Kuperis in 11/2001 issue of Latitude 38 magazine:
... Don't take breakdowns personally or think that you are unique in having problems. Yours is not a possessed vessel on which you have been duped into spending your life savings. She's a machine with logical explanations for her malfunctions. ... expect wear and tear that comes with a vessel in motion. ...

Frequently Asked Question:
How can I get a manual (or wiring diagram) for my boat ?

  • If the manufacturer is still in business, contact them.
  • Contact the owner's group, if one exists for that boat.
  • Find other owners of that type of boat and see if they have anything.
  • Otherwise, you're on your own. (Your boat may have been modified after manufacture anyway.) Trace systems and wires and examine components, writing down as much as seems reasonable. For major components, contact their manufacturers to get/buy manuals.


[This section doesn't mention obvious stuff such as wire, nuts and bolts, etc.]

Jim and Diane's "Spare Parts and Tools"
Chris Caswell's "Prepared for Anything"
SailNet - Liza Copeland's "Preparations for Going Offshore, Part Four"

Carry spares even if you don't know how to install them yourself. Having them in hand can save expense and weeks of waiting when you have a breakdown and find a mechanic in some remote place.

Inboard engine stuff

  • Fuel lift pump.
  • Gaskets for head, heat exchanger, oil cooler, etc.
  • Impellers for raw water pump.
  • Raw water pump rebuild kit.
  • Complete raw water pump.
  • Complete fresh water pump with pulley wheel.
  • Complete injector pump ?
  • Engine thermostat.
  • Complete engine starter motor ? Or maybe just the starter solenoid.
  • Complete alternator (with pulley already mounted) ?
  • Alternator rebuild kit (bearings, brushes, diodes).
  • Starter motor rebuild kit (bearings, brushes).
  • Engine starter motor solenoid.
  • Injector lines.
  • Injectors ?
  • Exhaust elbow.
  • Glass bowl for engine fuel/water separator.
  • Engine sensors.

Outboard motor stuff (maybe genset too)

  • Points and distributor kit.
  • Gaskets.
  • Ignition wires.
  • Spark plugs.
  • Carburetor rebuild kit.
  • Intake reed/leaf valve ?
  • Fuel filters.
  • Impeller and gaskets (rebuild kit) for water pump.
  • Fuel pump rebuild kit.
  • Fuel hose and priming bulb.
  • Propeller shear pin.

Navigation and controls stuff

  • Make and test a spare, jury-rigged rudder before cruising.
  • Spare tiller, and test it before cruising.
  • Steering cables.
  • Throttle and transmission cables.
  • Wind-vane panel/sail and break-away parts.
  • Auto-pilot actuator/motor (the part most likely to fail).
  • Auto-pilot belts and motor shear pins.

Refrigerator stuff

  • Replacement valves, gaskets and valve plate assembly for refrigerator compressor.
  • Spare (rebuilt) refrigerator compressor ?
  • Refrigerator RFD (receiver/filter/drier) ?

Sail-repair stuff

  • Slides/slugs.
  • Jib hanks.
  • Pieces of sail material.
  • Webbing straps (Dacron or Nylon).
  • Grommets and rings.
  • Battens.
  • Chafe patches (leather).

Rigging / deck hardware stuff

  • Winch parts (maintenance/rebuild kits) and special grease / machine oil.
  • Swageless fittings.
  • Bow roller.
  • Lines of all sizes: label with length, thickness, material and intended use.
  • Bolts for roller-furler and wind-vane.
  • Extra blocks and shackles.

Raw stock, for fabricating emergency parts (from Tom Neale)

  • Aluminum and wood stock.
  • Spray gasket (hot and cold types).
  • JB Weld adhesive compound.
  • Stainless steel rod stock (all-threaded and unthreaded types).
  • Thin plywood and Life Caulk to repair holes in hull.
  • Rubber inner-tube to cut up into gaskets, diaphraghms, insulators.

Moisture in air can degrade spare fuel and oil filters.

When you buy a rebuilt spare component, test it right away by using it. This ensures that it fits and works, that you have the tools to install it, and that the old part isn't frozen in place.


      Hammer       Swiss Army knife

From Rick Kennerly on The Live-Aboard List:
... it's not the tool but how you use it.

(I think I got that from the Playboy Channel -- they do a lot of home improvement stuff there).

"Basically, a tool is an object that enables you to take advantage of the laws of physics and mechanics in such a way that you can seriously injure yourself."
-- Dave Barry

[This section doesn't mention basic stuff such as screwdrivers, wrenches, etc.]

Jim and Diane's "Spare Parts and Tools"
SailNet - Don Casey's "Putting the Right Tools On Board"

AC power tools are more powerful than DC power tools.

From my brother Dan (carpenter, electrician, etc):
First, a can of WD 40. Near salt water all of your tools will go to pot unless you spray them down after use. Sockets, drill chucks, etc.

Hand tools: go to Sears. For hand tools, they have good quality in the Craftsman line and will replace any that break, ever, without a receipt. They are also reasonably priced and you can heft them before purchase.

Disclaimer: This applies to hand tools only. Do not buy power tools at Sears.

Power tools:

Here we have a dilemma. Normally, I buy good quality tools once. My saws and drills have never been on the disabled list, but they were expensive. The salt air may make this a bad option for you.

For a circular saw and a drill that are not too expensive you might consider a Dewalt. I don't use them because I don't think they are lifetime tools, but they should last you a while in salt air. If you want the creme de la creme of drills, buy a Milwaukee. They are double or triple the cost of a Dewalt but they last.

Remember, with any tool it is the blade that counts. When you buy your circular saw, buy two or three decent blades. No saw is any good with a bad blade.

If you need an angle grinder, look at a Makita, or a Dewalt again. I actually have two grinders, and the Dewalt has held up surprisingly well.

Spend Money On A Good Drill Index. You will use it a lot and appreciate it. Don't get brad pointed drill bits, they are great for wood but will not work in metal. You need a good general purpose set.

Buy a good heavy GFCI extension cord. Undervoltage is the prime cause of death in tools.


Other notes: On all tools, look for toolless blade changes or at least a spindle lock, which holds the armature and allows you to change blades with one tool.

I doubt you need a sawzall, but if you do, buy a Milwaukee super sawzall and nothing else.

You should consider a jig saw. They are handy and with the right blade can cut steel, wood, fiberglass, plexi, aluminum, etc. If you buy one, get a Bosch. Once again, there is no better jig saw, either to handle while working or for durability. They run about $150.

Electrical: I have several meters. The most versatile is a Fluke 11. It is digital, does AC and DC, continuity, etc. Auto ranging, rugged, shock and water proof.


From John Dunsmoor:
Another suggestion, this one is a little more esoteric: go with air tools. If you are going to be on this game and you have no investment in tools, air tools are great and can't electrocute the user. A drop of oil once a day, almost nothing to corrode, last forever, lower initial cost (except for the compressor), can be used in and under the water and will not electrocute the user. This last point is pretty darn important when you are attempting to buff the hull from the dinghy.

Buy from automotive tools/parts distributors/stores.

General-purpose tools

  • Mask and fins (and maybe medium-weight wetsuit) for emergency cutting of stuff wrapped around propeller or rudder, for bottom inspection/scrubbing, and for anchor-set inspection.
  • Kneepads; many jobs involve kneeling.
  • Heavy-duty gloves.
  • Compressed air for cleaning out air pump, air filter, carburetor, etc.
  • Teluminator from Carica, for picking up small parts dropped in bilge or under engine, or inspecting things in tight places ? $120 or so.
  • Magnet for picking up things dropped in bilge or over side, and for testing parts to make sure they're stainless steel.
  • Non-electric soldering iron.
    Can double as heat gun, for loosening frozen nuts and hoses, removing varnish ?
    Butane, with built-in igniter. Such as Weller Portasol. Really cheap small ones leak ?
  • Welding/brazing/cutting torch: oxy-MAPP torch, or something from a welding shop ?
    From Ken Hooper article:
    ... a tiny little oxy-MAPP torch that costs like $35 at Home Depot [or Sears], although I went through an alarming number of $7 disposable oxygen cartridges before the job was through. ... Although supplies for it are expensive I do not regret buying it. This thing is capable of field repairs if they don't require more than 10 minutes or so of welding, especially if you pre-heat with a straight propane torch before you start. A portable welder that's not much bigger than a shoe box is, I think, a good thing to carry with you ...

    A cheap real gas torch goes for $150 at your local welding supply and uses the cheap returnable oxygen bottles. ...
  • 12-volt Wet-Dry Vac. (Smaller better than bigger.)
  • Non-contact infrared temperature-tester (for looking for hot bearings, etc).
    Maybe at auto-parts stores or Radio Shack ?
  • Dremel (with various wheels and attachments).
  • Skilsaw.
  • Want toolbox made of industrial-grade plastic; no rust, and doesn't dent/scratch boat.
  • Magnifying glass or loupe (8 to 10 power) for inspecting rigging fittings.
  • Grease gun ?
  • 12V test lamp and continuity tester.
  • Multimeter (digital, with optional alligator clip on negative lead; recommended: Fluke 11). Would be great to have "data hold" features, which preserve the reading after you remove the probes.
  • Vise-grips (several sizes).
  • Portable vise. (Maybe Wilton 4 1/2 inch Tradesman ? Maybe vacuum-mount electronics vise.)
  • Telescoping, spring-loaded curtain rod (handy for holding things in position).
  • Small anvil.
  • Big pipe wrench.
  • Good flashlight (critical safety item).
    Tom Neale recommends Pelican brand.
    Beth Leonard recommends halogen dive lights submersible to 100 feet.
    LED flashlights reviewed in Practical Sailor's 3/2000 issue.
    Human-powered flashlights: Freeplay Energy, NightStar ($79).
    LED flashlights: Photon Micro Lights, Light Technology's PALight
  • Headlamp.
  • Funnel with filter screen and flexible neck.
    Maybe one for fuel/oil and another for water ?
  • Safety goggles.
  • Hearing protection.
  • Wire brushes for stripping paint.
  • Tap and die set.
  • Screw extractor set.
  • Heli-Coil set (AKA "Thread Repair Set", "thread inserts").
  • Pocketknife. Spyderco, Leatherman, Schrade are good.
  • A close-quarter or right angle drill.
  • Telescoping or dental mirror for seeing backs of things.
  • A come-along.
  • Manual (hand-powered) drill.
  • Small sledgehammer.


Chris Caswell's "Engine Essentials"

  • Penetrating oil.
    PB Blaster, Kroil or others.
  • Disposable rubber gloves (for working with epoxy, solvents, fiberglass, diesel, cleaners).
  • Respirators (for sanding, working with fiberglass).
  • Wooden tongue depressors (for stirring paint, mixing and spreading epoxy).
  • Caulks, sealants, solvents (acetone, MEK, muriatic acid, white vinegar, rubbing alcohol, mineral spirits, "Brush Cleaner" from Home Depot, "Goof Off", "Goo Gone", etc), cleaners, greases, paints.
  • Electrical tape (buy good quality; maybe "self-vulcanizing rubber tape" ?).
  • 3M waterproofing "gunk" for making watertight underground splices.
  • White electrical tape for labeling wires.
  • Plastic ties (black better than white) in various sizes.
  • Sandpaper.
    Keep only wet/dry sandpaper on board; dry paper absorbs moisture and disintegrates.
    If clogged, wet/dry sandpaper can be scrubbed with warm water and detergent, then dried.
    Sandpaper tested in 5/15/2001 issue of Practical Sailor. Conclusion: premium paper (Carborundum Premier Red, Norton Blue A975, 3M Imperial Purple) is well worth the higher price.
  • Beeswax rings. From David Urbanski in Good Old Boat newsletter:
    ... a wax ring, the 99-cent beeswax ring you put around the seal of your land-based head. You can buy them at any hardware store, and they last forever. The beeswax is an amazing thing; it can stop water from entering or exiting just about anything. It can be molded to fit any hole and used with any type of surface, as long as you do not have a heat source close by since the wax will melt.

    The wax is also great in that once you have used it, it's easy to clean away once the repair is made. ...
  • "3M makes its own version of Velcro called Dual Lock that is much heavier duty than normal Velcro."
  • Click Bond patch kits for repairing tank leaks.
  • Marine-grade Never Seize.
  • A couple of wire clothes hangers.
  • Duct tape has water-soluble backing and messy adhesive; use "100 MPH Tape" instead (from

Rigging tools

  • Loos rig-tension gauge ? $100 or so.
  • Nicopress kit (for rigging).
  • Dye/oil for finding cracks in fittings (e.g. Magnaflux, Ardrox, Spotcheck Red Dye).
  • A "strand grip".
  • Cable cutters (recommended: Felco's).

Sail-repair tools

  • Sewing palm.
  • Needles (lots of strong ones).
  • Hot knife.
  • Seam ripper.
  • Scissors.
  • Straight-edge.
  • Push pins (with wide heads, for pinning sail to wood surface).
  • Pony clamps.
  • V-92 sewing thread.
  • Double-sided seaming/basting tape.
  • "Rip-Stop" adhesive-backed sail fabric.
  • Sail-repair tape: want Dacron, not Nylon.
  • Sewing machine: see my Boat Sewing Machine page.
  • Grommet/ring/fastener kits (including cutters and dies).

Basic refrigeration tools

  • Continuity tester.
  • Multimeter.
  • Thermometer to test temperature of refrigerator.
  • Hair dryer to melt ice.
  • Arsenic-free sealant rated for use in food compartments.
  • Oven baster for forcing hot-water-and-baking-soda solution into drains.
  • 12-volt power cable from light socket to alligator clips, with fuse.
  • Dental mirror for seeing backs of things.
  • Thin plastic tubing for clearing obstructions in pipes/drains.

Advanced refrigeration tools (for purging/recharging)

From "The Boatowners Mechanical and Electrical Manual" by Nigel Calder:
... [since 1994] only EPA-certified technicians can buy refrigerant. ...

... Since 1993, the only people allowed to open a refrigeration system [coolant loop] have been certified technicians. Any procedure beyond a simple topping-off clearly constitutes "servicing" or "opening" an appliance and as such [must be done by an EPA-certified technician]. ...

Getting EPA Technician Certification

  1. Buy a study manual from ARI.
  2. Study.
  3. Find somewhere to take the test (maybe from HVAC Training Schools).

  • Leak detector. (Electronic halogen detector $200 to $300)
  • Vacuum pump. (e.g. Robinair 15234 for $425)
  • Combination gauge set (2 pressure/vacuum gauges, 2 valves, 3 ports in one body). (e.g. ATD-3201 for $60 includes hoses)
  • Charging cylinder full of refrigerant. (e.g. Robinair 43678B for $307, includes heater and gauge)
  • Cans of refrigerant.
  • Refrigeration oil ?
  • Empty service drum or cylinder (for purging; put it in ice water).
  • 3 hoses to connect everything together.
  • Gloves for protecting from "finger burn".
Must have service valve (port) on low-side tube of refrigerator's compressor.


Engine tools

  • Torque wrench.
  • Coolant tester.
  • PELA Oil Extractor
  • Mail-in oil analysis kits.
    Chris Caswell's "Oil Analysis"
    "BoatU.S. sells kits in their catalog for $18.
    All the major oil companies and engine manufacturers have programs.
    Pennzoil and Quaker State offer kits through their distributors that cost $3 or $4 per sample."
    Oil-changer guy at boat-show said a one-time oil-analysis is useless. Only if you do a series of analyses over time and see the trends over time do you get useful info.
    "... oil to be tested should have at least 25 engine hours on it."
  • Oil-filter wrench.
  • Engine-belt tension gauge (Krikit or NAPA #KR1 for $10, or something fancier).
  • Feeler gauges and spark-plug gapper, for outboard spark plugs.
  • Engine compression gauge.
  • Mechanic's stethoscope.
  • Flush kit for running fresh water through outboard motor cooling system: "rabbit ears" with hose fitting ?
  • Impeller puller (allows you to pull and check an impeller without destroying it).
  • Special tool for removing outboard motor flywheel.

Battery tools

  • Battery hydrometer with built-in thermometer.
  • Battery terminal pullers, wire brush and other battery tools.
  • High-rate discharge battery tester.
    NAPA battery load tester ($49)
  • Jumper cables ?
  • Distilled water.

Plastic welder

From Greg Hanka on the IRBS live-aboard mailing list:
I ordered my 2.8A (336W) Hejet plastic welder, plus the "high speed tip" plus two pounds of rods of each of the six most common plastics. That is probably a lifetime supply for a recreational user like myself. It came a few days later as promised. I had also ordered one for my brother, and it arrived at his house on time as well. I used both welders and they behaved identically, so Hejet quality control is at least satisfactory.

The gun itself is a glorified heat gun, apparently with very precise temperature control. It is made of chromed steel and plastic. Considering it won't be used that often, it would be safe on a boat if kept in a dry container.

The instructions that come with the unit are pretty pathetic. I expected at least a color booklet describing how to weld, or even better a short video, but there were just a couple of xeroxed pages giving a general overview of the process. You're basically on your own to learn by experimentation. The instructions do say that it takes about 30 minutes of practice to get the hang of it, and they were exactly right. After a frustrating half an hour with my brother's gun, I was able to weld one piece of rod to another piece of rod (of the same kind of plastic of course) and have the weld be stronger than the rod itself. That is the indicator of success, says the instructions, and it is quite easy once you learn the look and feel of the process. Both the Hejet people and now I too strongly recommend buying the "high speed tip", because it makes the process vastly faster and easier.

Anyway, after the practice session I went on full alert, waiting for something made out of plastic to break so that I could fix it. ;) The opportunity presented itself four days later. My wife's HP Palmtop computer cover hinge finally gave out, after going six months in a nearly-broken state. She immediately began agitating for a new palmtop computer, since hers really wasn't usable with the broken cover. Somewhat nervously, I attempted my first 'real' weld on the palmtop. I guessed that it was made of PVC plastic, which turned out to be right. (The welder comes with decent tips on how to figure out what kind of plastic a thing is made of.) Then I fired up the gun and just did it, and was fairly surprised that I got it right on the first try, without melting the surrounding case plastic much at all. The hinge works perfectly now, and I was unable to pry off a piece of welded plastic from the case with a razor, so the bond was good. Indeed, this is the first time that a gimmicky tool has actually, truly paid for itself on the very first usage.

Wifey was impressed, as you might imagine. The idea of actually repairing a broken plastic item is surprising to most people. The only difference between my weld and that done by a pro, I think, is the aesthetics ... mine is perfectly strong but not real smooth, even after a bit of filing. It's still fine though.

So plastic welding is for real, and the Hejet tool works as advertised. I don't have any experience to know if other types of plastic welders (e.g., soldering-gun type) work better, but I don't think they do: hot air seems to be the simplest way to uniformly heat a controlled area of two separate pieces of plastic. Of course, hot air welders are four times the price of soldering- gun welders. :(

Eventually, I'm going to build some polyethylene holding tanks and buoyancy tanks in the odd shapes needed on board my boat, now that I'm certain that I can make genuinely strong welds in plastic. In fact polyethylene seems to be one of the easiest plastics to weld.

From Stuart Burgess:
One of the most useful tools I have on my boat is a vacuum pump. I bought it from a specialist car accessory shop but they are advertised in the West Marine catelogue as an 'oil boy' fluid extractor kit.

I use it for removing water from difficult places. I discarded the 2nd extension pipe and replaced it with a length of copper tubing in which I placed a gas tap as an on/off switch. I covered the copper tube with a piece of plastic hose so not to damage any joinery and now to suck water out of tricky places I simply place the end in the water, pump the container to depressurise it and then open the on/off tap to begin extraction.

It has saved me many hours of work.

SCUBA equipment: see my SCUBA Diving page.

On-line stores:
Harbor Freight Tools

A wench is used to turn a dolt's head.

Troubleshooting / Techniques

"The man who would be fully employed should procure a ship or a woman, for no two things produce more trouble"
- Plautus 254-184 B.C.

Cruising World's "Find It, Fix It, Maintain It"
Don Stewart's "Rust Ye Merry"
David Pascoe's "Attaching Hardware to Your Boat"
SailNet - Sue and Larry's "Drilling and Filling Holes in Your Boat"
Don Casey's "Installing Hatches and Deck Plates"
SailNet - Tom Wood's "Mounting Deck Hardware"
"How to Drill Holes" by Wayne Redditt in issue 2000 #2 of DIY Boat Owner magazine
David Brown's "Repairing Loose Bulkheads"
Chris Caswell's "Quick Engine Repair"
SailNet - John Kretschmer's "Tips for Going Overboard"


  • Must-have books:

    • "The Boatowners Mechanical and Electrical Manual" by Nigel Calder.
      Contains theory, installation, troubleshooting, repair info for many things.

    • "This Old Boat" by Don Casey.
      Walks through simple and complex projects in many technologies.

  • Very-good-to-have books:

    • "Modern Boat Maintenance" edited by Bo Streiffert.
      Tips and projects for hull, deck, rigging, sails, engine, electric.

    • "Marine Diesel Engines" by Nigel Calder.
      First half is theory and design, but second half is troubleshooting, overhauling, installing.

  • Good-to-have books:

    • "Complete Guide to Boat Maintenance and Repair" by David G. Brown.
      General techniques (drilling, gluing, fiberglass, bedding deck hardware, etc) and then specific tasks (fixing blisters, fixing leaks, improving ventilation, maintaining winch, etc).

    • "The Compleat Book of Yacht Care" by Michael Verney.
      A lot on painting, and splicing. Pretty good on engines, mechanics, fittings, dinghies. Slightly dated (1986) and slightly British/wood-oriented.

  • Worth reading:

    • "The Self-Sufficient Sailor" by Pardey and Pardey.

    • "Your Boat Belowdecks" by Thomas Reale and Michael Johnson.
      Maintenance and troubleshooting of engine, electrical, pumps, head, etc.

    • "Improve Your Own Boat" by Ian Nicolson.
      Odd mix of small and large projects, tips and anecdotes.

    • "The Boat Repair Manual" by George Buchanan.
      Covers a lot of territory, including various hull types, all parts of boat, equipment, maintenance. Slightly dated (1985) and somewhat British/wood-oriented.

Cap'n Drew, quoted in 9/2002 issue of BoatU.S. magazine:
> I was given a 1972 trawler which has not been in
> the water for over 10 years, and needs a considerable
> amount of work on hull, cabin and engines.
> What book should I get to help me ?

You might want to consider the Bible. I think you're gonna need a lot of prayers to get you through this one. ...

Don't put off repairs to critical systems: engine, dinghy, pressure water system, batteries, ground tackle. If the weather changes and you have to move or have to stay a while, those systems must be up.

Rebedding Deck Hardware

Mostly from "The Voyager's Handbook" by Beth Leonard:
  1. Remove the hardware.
  2. Sand and clean the deck with solvent.
  3. Drill out holes, clean out dirt.
  4. Remove coring around holes.
  5. Fill holes with epoxy, drain it out, then fill with thickened epoxy, let it harden.
  6. Drill and tap bolt holes.
  7. Dry-fit the hardware, tape on and around the hardware, then remove the hardware.
  8. Put lots of sealant on hardware and bolt heads and deck (but not on backing plate).
  9. Tighten slightly, let dry, trim, tighten a little more.

From Jay Fraser on the Yacht-L mailing list:
... The stanchion job is perfect for practice: you are replacing rotten balsa wood, so ANYTHING you do will improve the situation.

0) Clean everything w/ acetone. Wear breathing mask.
1) Put tape over bottom hole.
2) Fill with un-thickened epoxy (this wets out the surfaces inside hole).
3) Pull tape, catch epoxy that leaks out, clean up spills.
4) Put new tape over bottom hole, thicken epoxy.
5) Force as much epoxy into hole as possible, w/o popping tape off bottom.
6) Repeat as necessary.
7) Go drink ONE beer. You won't need any more after all the acetone fumes you've been inhaling.

From Norm on The Live-Aboard List:
Make up the joint using spacers to insure an adequate layer of sealant between the base and the deck. I use 1/8" diameter pieces of wire.

I first make up the joint dry with the fasteners to make sure everything fits well. Draw a pencil line around the joint. Take it apart and put blue masking tape on the deck at the pencil line, and around the edge of the object to be bedded. It is much easier to apply the masking tape than it is to clean up the excess without masking tape.

Then tape down the pieces of wire to the deck with just a little of the wire over the line so that it is between the deck and the object. Then put down a generous bead of bedding and make up the joint. The wires insure that there will be exactly 1/8" of bedding between the object and the deck. The next day remove the tape and wires and clean up. Do not put any load on the joint that will squeeze the bedding out. You might try methods that will remove the tape and excess bedding but leave the wires in place. Wait until the bedding is cured to a quite firm state and then tighten up on the fasteners.

The object is to make a perfect formed-in-place gasket 1/8" thick and then put it under compression.


The wrong thing is to squish all or most of the bedding out. This will leave a very thin gasket so that the slightest movement of the object will break the adhesive seal of the bedding material and allow water to wick in.

From "Good Boatkeeping" by Zora and David Aiken:
  • Use "Rubba Weld" tape for emergency repair to water hose.
  • Put little tape marks on all engine gauges to show typical reading; any change may mean a problem.
  • If electronics get wet with salt water, rinse them with fresh water.

Paraphrased from "This Old Boat" by Don Casey:
Basic skills to acquire and practice:
  • Fiberglass work.
  • Rigging.
  • Mechanics.
  • Carpentry.
  • Electrics.
  • Plumbing.
  • Painting.
  • Sewing.

Sealants / caulks

Mostly summarized from article in March/April 2000 issue of Good Old Boat magazine:
  • Silicone:
    • Flexible.
    • Chemically impervious (fuel and oil resistant).
    • Compatible with plastics.
    • Good for separating dissimilar metals.
    • Cures rapidly.
    • Weak bonding, especially to wood.
    • Can't be sanded or painted.
    • Needs UV-inhibitors and mildewcide mixed in; only use marine-grade.

  • Polysulfide (e.g. Boat Life's Life Calk, 3M 101):
    • Can melt some plastics, acrylics, Lexan, vinyl.
    • Bad for separating dissimilar metals.
    • Less elastic than silicone.
    • Cures slowly.
    • Can be sanded or painted.
    • Can last 20 years.
    • PolyGone removes polysulfide caulk.

  • Polyurethane (e.g. 3M 5200, SikaFlex 292):
    • Extreme adhesion; near-permanent bond (3M 4200 less permanent).
    • Cures very slowly.
    • Diesel fuel softens/damages 5200.
    • After you open and then close a tube of 5200, the whole tube solidifies in a few days to a couple of months (depending on who you ask).
    • 5200 can't be sanded.
    • To remove polyurethane/5200: Anti-Bond 2015, or turpentine (soft while wet with turpentine; when dries, it's hard again), or Lestoil floor cleaner.

  • Flexible Epoxy (e.g. Flexbond Marine Epoxy):
    • Expensive.
    • Near-permanent bond.
    • Cures underwater.

Summarized from "Complete Guide to Boat Maintenance and Repair" by David G. Brown:
  • Silicone: shorter lifespan, can peel loose, damages some plastics.
  • Polysulfide: best for ports, deck hardware, everything.
  • Polyurethane: too permanent for most jobs.

From SailNet - Don Casey's "Choosing and Using Sealants":
... think of silicone as a gasket material instead of a sealant ... because it depends upon mechanical compression to maintain its seal, silicone is also a poor choice for sealing hardware on a cored deck ...

... You can - and should - use polysulfide to bed almost everything. ... One caution: do not use polysulfide to bed plastic.

... Consider polyurethane an adhesive [that forms a permanent bond] rather than a sealant.

BoatLife's Life Seal: part silicone and part polyurethane. ... this mixture promises a longer-lasting seal for deadlights and other plastic fittings where compression of the sealant cannot be assured. ...

Solvents for cleaning up:
  • For silicone, use acetone.
  • For polysulfide, use mineral spirits.
  • For polyurethane, use rubbing alcohol.

Summarized from John Dunsmoor:
Use 3M 5200 when bonding to metal; the bond can be broken later by heating the metal.

Don't use 3M 5200 when bonding two pieces of fiberglass/plastic together; the only way to get the bond apart later is to saw down it.

From Bill Millson on the Morgan mailing list:
... 5200 and 4200 do not weather well in the sun -- mine started chalking and giving off black marks within a few months ...
From LB on the Morgan mailing list:
... let the 4200 cure well then sand lightly and paint. I have done this before and it works out well. The 4200 or 5200 is fine after years. It is only the UV that gets to it.

West Marine's "Sealant Selection Chart"

To smooth wet caulk without sticking to it, dip tools or your fingers in detergent such as Joy.

Any time you're rebedding deck hardware, consider taking the opportunity to add bigger backing plates to it.

For sealing deck leaks: Elmer's Squeez-N-Caulk (siliconized acrylic latex) ?

Don't use acetic-acid-cure silicone (with vinegar smell) on copper or aluminum.

From my brother Dan:
[When I complained about a cap that split and let all of my caulk dry in the tube:]
Buy a 99 cent toilet bowl wax seal, the very cheapest possible, and dip your caulk tubes into it when you finish a job. The wax will seal the end better than any cap can, and you can just squish it out later.

From Gary Elder:
[After he told me not to use silicone to bed metal hardware
or teak strips onto fiberglass deck:]
> Okay, so when should I ever use silicone ?

Silicone is good for metal, glass, lexan, abs plastics, etc.

> Is polysulfide harder to get off later ?

Not really, polysulfide may seem harder to remove, but silicone leaves a residue behind that can cause polysulfides to not stick real well.

I haven't purchased silicone sealant for this boat - ever.

From Marce Schulz on The Live-Aboard List:
> When we used BoatLife polysulphide, we had to re-do the entire deck
> because the stuff had cracked inside.

Wow! Same thing happened to us! We got BoatLife to replace the stuff that didn't work (although they didn't admit liability of course, and the labor involved was tremendous) but in the end we decided not to chance a complete product failure again and went with Teak Decking Systems SIS 440, after testing about 5 different products on the fantail and waiting a year to see what held up best. In fact, we just finished the job 2 weeks ago. We may even consider using the same stuff to bed the deck hardware. It's a joy to work with.

From Bob Hinely on The Live-Aboard List:
Lifeseal is a mixture of polyurethane and silicone. It is an excellent sealant for Lexan-Fiberglass ports.

From Ken on Cruising World message board:
There is a known chemical incompatibility between CETOL and Boat Life 2-part polysulfide caulk. The CETOL when applied over the caulk eventually breaks it down. You end up with a sticky mess, the caulk "bubbling" out of the seams like tar on an old ship. Heat (hot days) seems to accelerate the problem.

From Cam Foster on SailNet's Gulfstar mailing list:
... After struggling a number of times through the process of removing the old caulking, I found a "magic" product made by Boatlife called Release -- an adhesive and sealant remover. Costs about $16 for a 16-ounce spray bottle. Spray it on the old caulking (even at the top of the windows), wait a couple of minutes and you can almost pull the old stuff out in a string, with some help of a skinny putty knife. It even works on relatively new caulking ... If you spray it on and then change your mind, let it dry and it re-seals. ...

From Sailingdog on SailNet forums:
Marine Sealants in a Nutshell

One thing you have to do on boats is bed hardware. This has to be done on a regular basis, especially with hardware that is under heavy cycling loads, like cleats. However, using the right sealant can make this task much simpler.

Most people are familiar with silicone caulk, since it is the most commonly used type of caulk in normal household repairs. However, while certain Silicone-based bedding compounds are excellent for bedding ports, most of the time, silicone caulks really serves no useful purpose on a boat beyond bedding ports and covering the ends of cotter pins.

In most cases, on a boat, you want a sealant that will adhere to the two surfaces being joined — whether it is a through-hull and the hull or a cleat and the foredeck. The sealant should have a fair bit of elasticity so that it can stretch when the hardware moves or shifts under load without detaching from either side and breaking the seal.

For deck hardware and through-hulls, countersinking the fastener holes is probably one of the best things you can do, since it gives the sealant a natural place to form an o-ring-like seal.

There are four major classes of bedding compounds/sealants used on a boat:
  • Polyurethane-based sealants such as 3M 4200 and 5200, SikaFlex 291, 292, 295, 296.
  • Polysulfide-based sealants such as LifeCaulk and 3M 101.
  • Silicone-based sealants, such as Dow 295.
  • Butyl Rubber Glazing tape — this is not butyl rubber caulk.
Each of these sealants has specific pros and cons.

Polyurethane-based sealants are basically adhesives with sealant properties. They are often very permanent and have very strong adhesion strength, and can be used both above and below the waterline.

3M 5200, a polyurethane sealant commonly found in marine chandleries, is basically for all intents and purposes a permanent adhesive and should not be used on boats for the most part. 3M 5200 has a bonding strength so high that it can often cause delamination or damage the gelcoat when you try to remove hardware bedded with it.

However, polyurethane sealants have some of the best materials compatibility, so the less aggressive ones, like 3M 4200, are very useful. SikaFlex 291 and 292 are probably better choices, but usually more difficult to find. For bedding ports, Sika 295 or 296 can be used in place of Dow's 795 Silicone.

Be aware that using a polyurethane sealant can make removing hardware much more difficult than using other sealants. There is a solvent, called DeBond 2000, which can be used to weaken the bond if you need to remove hardware that was bedded with 5200. One other issue with the polyurethane sealants is that they have a relatively short shelf-life, once opened. This is due to their being moisture-curing compounds, and once exposed to the moist sea air ... they start to cure ... and you eventually end up with a solid tube of cured sealant.

Polysulfide-based sealants are the best general-purpose sealants for marine use. They are not as aggressively adhesive as polyurethane-based sealants and generally a bit more elastic and flexible. They can be used both above and below the waterline, like the polyurethane sealants, and are better than polyurethane-based sealants for hardware that has to be re-bedded more frequently.

Polysulfide-based sealants are excellent for bedding wooden items, like rubrails and cockpit coamings, since it adheres fairly well to teak. The fact that these items often need to be removed for periodic re-finishing makes it ideal IMHO.

The main drawback of polysulfide-based sealants is that they tend to attack many common plastics — most commonly acrylic and polycarbonate. They are safe to use on acetal, delrin, nylon, and marelon fittings though. If you're not sure what the fitting is made of, don't use polysulfide-based sealants with plastic fittings.

Silicone-based sealants aren't really sealants IMHO. They're really gasket materials, and need to have a minimum thickness and be kept under compression to work properly. Silicone-based sealants should only be used in above-the-waterline applications.

The only structural silicone sealant that I generally recommend is Dow 795. This is a structural adhesive which is generally recommended for bedding ports. It is not your common silicone caulk. However, beyond the very specific use of bedding acrylic* ports, it should not be used on boats.

Aside from bedding acrylic and polycarbonate ports, and certain plastic parts, like Beckson ports, and covering the exposed ends of cotter pins — it really has no place on a boat — primarily due to the residual silicone contaminants silicone can leave behind. These contaminants are almost impossible to remove thoroughly, and will prevent other sealants and paints from adhering to the surface properly. Even strong adhesives, like epoxies, have trouble bonding if the surface has silicone contaminants on it.

One other use of silicone is for sealing potable water tanks. However, I highly recommend that you use only NSF approved silicone sealants for potable water tanks and systems. These will not have any toxic components, unlike some of the other marine-grade sealants which may contain isocyanates.

Some silicone sealants are acid-curing and should never be used on metal. These are generally easily detectable by the strong vinegar smell caused by the acetic acid that is contained in them.

The last sealant is butyl rubber glazing tape. This may be one of the most versatile sealants you can use on a boat. However, it has the weakest adhesion and tensile strength and highest elasticity of any of the sealants. It is also the most easily affected by other chemicals, as it doesn't cure like the other sealants do.

Unfortunately, many petrochemicals and common solvents will dissolve or damage it. Because of its sensitivity to petrochemicals, I generally don't recommend it be used below the waterline.

It is great for bedding deck hardware, especially things like chainplates, where a certain degree of movement is unavoidable. It has the greatest materials compatibility of all the sealants and is also probably the least expensive of them.

One major advantage of butyl tape, since it doesn't cure, is the working life. This makes it ideal for bedding things like traveler and genoa fairlead tracks. The lower physical strength of butyl tape generally isn't an issue due to the large number of fasteners generally used on these tracks.

Other Sealants

Two other sealants of note for marine use are 3M 4000 UV and BoatLife's LifeSeal.

3M 4000 UV is a polyether based sealant, and as such is generally fairly well suited for use with plastics. However, it is not recommended for below-the-waterline uses. It cures relatively quickly, as it is tack-free in under half-an-hour and cures in 24 hours or so.

BoatLife's LifeSeal is a hybrid polyurethane/silicone sealant. As such, it isn't as permanent as a pure polyurethane sealant, but is more an adhesive bedding compound than a pure silicone material. However, it still has many of the contamination issues that any silicone based sealant will have. It also is fairly inelastic, and IMHO, 3M 4000 UV is a better choice.

*Most marine ports should be made of cast acrylic, rather than polycarbonate, due to several physical characteristics that make polycarbonate less suitable. First, polycarbonate tends to deform under load, which can cause it to shear the adhesion of the glazing to the underlying sealant. Second, it is less scratch and UV resistant than acrylic. Third, it is more difficult to find polycarbonate in UV/scratch resistant versions in sizes thicker than 1/4".

My experience:
I used to use 3M 101 (polysulfide) caulk on everything except plastic ports (used BoatLife Life Seal on those).

But the price of 3M 101 kept rising and it got harder to find. So I've switched to using generic acrylic latex "tub and tile" caulk. It's paintable and interior/exterior and "provides a water-resistant seal", and costs about 1/5 as much as 3M 101. Will have to see how well it works and lasts.

I've never used 5200 or 4200 adhesives on my boat.

I've used silicone caulk on the pilothouse trim and pilothouse windows, but nowhere else.

From Ocean Navigator: Roger Hellyar-Brooks "General Fabrication":
... In review of all the goops and glues we could use to connect things to the boat, some are better suited than others, but there are many methods that can work, as well. When fastening a composite or plywood structure to a boat (fiberglass or cold-molded wood), it is hard to beat the versatility and strength of an epoxy bond. Some vinylester resins have good secondary bonding characteristics (anything after the boat is molded), but avoid polyester resins, since they are good for boat construction but do not make the best adhesive.

The prep work for all bonding must be done carefully, because, as with painting, preparation is the key to a successful job. First scrub the area on the hull or deck with anything that gets kitchen floors clean and dewaxed. You'll know you are successful when the rinse water "sheets out," which is the opposite of water beading on a well-waxed surface. Do this before you even think about grinding or sanding, since that will cause you to drive contaminants into the surface. After washing and rinsing, wipe the surface with alcohol or acetone (ventilate well) and abrade the surface to provide a mechanical advantage. ...

Surface preparation (summarized from article by Brian Knight in Epoxyworks #20 Fall 2002):
  • Don't wipe a surface with an organic solvent unless there is good evidence that an organic contaminant is present.

  • Organic solvents can dissolve contaminants from rags (silicone from fabric softener, plastic from man-made fibers) and deposit them on the surface.

  • Use white or unbleached paper towels, not rags. Use them to wipe solvent on, and then more to dry the surface. You want to wipe the solvent off while it is still wet.

  • Don't rub your bare hand over a freshly sanded surface; that deposits skin oils and salt onto it.

  • To get sanding dust off: vacuum it, brush it, or wash off with clean water. Compressed air can have oil in it.

  • Commercial "tack rags" may deposit a residue. Solvent in paint or varnish may handle the residue, but epoxy won't.

  • Don't use sandpaper that has been treated with zinc stearate; that can contaminate the surface.

  • Amine blush (wax-like film) on cured epoxy is water-soluble.

  • To test for clean surface, wash it with clean water and look for beading or channeling caused by contaminants.

  • For good adhesion, surface should be clean, dry, solid, and either porous or abraded (sanded).

Underwater repair compounds

Summarized from article in 12/2001 issue of Practical Sailor:
Not many products specifically targeted at this use.

Some hull types (wood, aluminum) very hard to bond to.

No products were entirely satisfactory: some too slow-curing, some too weak.

Bio-Fix 911 cures quickly but only moderate holding. Use duct tape or wedges to hold a plate on, and Bio-Fix 911 to seal joint.

Epoxy sticks (AquaMend, QuikAluminum) good for filling small holes.

Replace stores of products every year or two.

From letter by John Vigor in 1/15/2002 issue of Practical Sailor:
Use a mixture of tallow and fast-setting Portland cement. Doesn't set until put underwater. Get a watertight can of the cement.

Remove frozen/corroded nuts/bolts/fittings

Chris Caswell's "Fastener Removal"

Remove a frozen nut:
Partly from "Sailing Tips" by William M Burr Jr, partly from article by Ken Textor in 6/1998 issue of Cruising World magazine:
  • Clean nut before trying to loosen it; rust/dirt increases chances of rounding it off.
  • Use box-end wrench, not open-end or adjustable wrench, or pliers.
  • Try tightening nut slightly.
  • Tap the nut gently with a hammer.
  • Use penetrating oil (or Diet Coke, which has phosphoric acid in it) (or Coca Cola and baking soda).
  • Use vinegar on rusty nut (dissolves aluminum oxide over time).
  • Use nutcracker to split the nut.
  • Heat the nut.
  • Drill diagonal hole in nut to expose threads to penetrating oil.
  • Drill small holes in nut (don't hit threads) until it can be chiseled apart.
  • Weld a bigger, square nut to the stuck nut.

Remove a frozen or sheared bolt/screw:
If head is still on:
  • Clean head before trying to loosen it; rust/dirt increases chances of destroying slot or rounding off hex head.
  • Use the best tool first (the proper size screwdriver, or a box-end wrench). If you damage the head with the wrong tool before trying the best tool, the best tool may fail too.
  • If a bolt doesn't move easily, use penetrating oil immediately, before applying excess force and maybe breaking something.
  • Try tightening it slightly before trying to loosen.
  • Tap gently with a hammer onto the screwdriver, to shock the bolt, and to seat the screwdriver well into the slot.
  • Substitutes for penetrating oil: Diet Coke (has phosphoric acid in it); Coca Cola and baking soda; vinegar (dissolves aluminum oxide over time).
  • Heat the nut or the bolt/screw.
  • Use an impact wrench.
If head is snapped off:
  • Use file or Dremel to cut a new screwdriver-notch in top of the remaining shaft.
  • Hammer a wrench onto the shaft, then turn the wrench.
  • Drill hole in top of the remaining shaft, then insert screw remover/extractor (left-handed screw; AKA "easy-out").
    Start with very small drill bit.
    Use a high-quality carbide or cobalt or titanium-coated drill bit.
    If top of shaft is flush and flat, use a center punch to make a dimple in the center of the shaft before drilling.
    If top is not flat, use a file or Dremel to make it flat before punching.
    If top of shaft is below surface, hammer a hardwood dowel into the hole and cut it off flush; the dowel will help support and guide the drill bit.
  • Drill entire screw out. Far better to use a drill-press rather than a hand power-drill.
  • Use a "hammer drill" (or "drill hammer" ?).
  • Weld a big, square nut to the head of the stuck bolt/screw.

From yachtgilana on The Marine Doctor's Forum:
Extraction of broken bolts and studs:

OK, here is the broken stud 101, that I use, and have used successfully many many times. Credit goes to Graham my Audi technician from Cape Town who taught me this. The smallest bolt I have extracted is 6 mm and the biggest 22 mm. It's not cheap but it works.

  1. Get a flat-ended pin punch, and beat the end of the stud square and flat, use many light taps, like hundreds!

  2. Get a centrepunch, and even if you have to grind it especially, punch a dot in the centre.

  3. Start drilling with very small bit, watch your feeds and speeds, make sure there is swarf coming out the hole otherwise the metal you are working is work-hardening (then give up) this is especially true on stainless.

  4. Keep a cool tool! Lube the cutting edge, go get out there and buy the cutting oil in a spray-can, it's worth it!

  5. Now go out and buy a torx or spline drive socket or driver. For those who don't know what it is, it's either a socket that fits on your socket set that has a very hard tip consisting of six sharp points in the case of torx, or 12 in the case of a spline, or a screwdriver type. They are numbered, like Torx #6 etc. Buy one that is smaller than the ID or root diameter of the thread in practice 1/3 the OD (leaving a third of "meat" either side of the hole otherwise it will shear off again).

  6. Examine the torx from the end, see that there is an inner and outer diameter ... (the valleys and peaks of the points) your final hole is the same size as the INNER diameter, like it won't fit right ... right!

  7. Take the torx to your bench grinder, and grind the tip, without overheating it, so that it is 90 degrees and has SHARP points not the nice shamfered end as new which aids getting it into the torx head screw.

  8. Hammer the thing into the hole you have meticulously prepared, the points should cut their way into the metal of the screw AND NOT EXPAND IT so that it is even tighter!

  9. Attach your handle and unscrew the little bastard!

Stainless steel fitting corroded onto aluminum mast:
Connect battery ground to aluminum, briefly touch battery positive to stainless steel. Heating at boundary will help free it.

Bronze frozen onto bronze: use Tabasco sauce.

From Ike Harter in Good Old Boat newsletter:
Get some glazier's putty, children's modeling clay or electrician's caulking compound and build a small dam around the nut or cap screw that is frozen in time. The stuff needs to be oil-based, not water soluble, such as Play-Doh or other washable goo. Degrease the area, and remove any penetrating oil you might have tried before.

The little dam needs to be molded so that it will keep the nut, screw head, stud end, or whatever is stuck, submerged in at least two ounces of liquid. Now fill the reservoir with regular Pepsi-Cola. Coke and some of the other colas and soft drinks may work, but Pepsi has more phosphoric acid, which is what does the job, along with the carbonic acid and something in the formula that makes the liquid penetrate into the threads and cracks.

Check each application for leaks and leave it alone for about six hours. If you have several stickers, make as many dams as you need. Check in an hour or so for leaks, but leave it alone and let it work. Don't loosen the dam just yet, unless you cannot get the wrench on the nut. In most cases the fastener will unscrew as if by magic. If it is still frozen, try another application of fresh Pepsi. Six hours later if it still will not move, then you need a nutcracker or cold chisel. Your problem is beyond the capabilities of channel locks and Vise-Grips.

Another possibility, which has caused many salty words from mechanics and sailors alike, is that there may be a hidden problem that even Pepsi cannot dissolve. If you don't know the history of the machinery or the fastener, consider this. Some well-meaning soul may have applied a LocTite compound to the joint. It might as well be welded.

LocTite is a family of anaerobic, cyanoacrylate resins which have unusually good penetrating qualities and which harden when out of the presence of air. If you think this may be the case, done either at manufacture or during a repair, get an ultra-violet "black-lite" source and in a darkened space, illuminate the subject in "black-lite". Any traces of LocTite will fluoresce in a color that will indicate the grade of LocTite that was used. Get out your propane torch or a really big soldering iron. The joint or fastener will need to be heated to about 350 degrees F before it will break down the resin. The fastener will need to be unscrewed while hot.

Never apply anaerobic thread and bearing sealant compounds without first considering whether you or some poor unsuspecting person will come after you and end up losing their temper, manners, and religion over a very tight joint.

On the matter of penetrating oil, most of the naphtha-based graphite suspension products have been withdrawn because of the carcinogenic qualities of the liquid. An alternative is Oil of Wintergreen, sold at the pharmacy, but try Pepsi first. Buy it by the case for flushing out fresh and seawater corrosion in motor blocks, pumps, and circulating systems. Good stuff.

From Norm on The Live-Aboard List:
Aluminum has twice the expansion of steel. To get the wheel off a shaft, I would apply a gear puller, with lashings or spiral clamps for security, put as much tension on it as you dare, then apply significant heat to the hub of the wheel. Personally, I find that lots of heat applied quickly, before it has time to spread, works best. ... invite all your friends and ask them to each bring a propane torch. Apply all the torches at once. When the heat is as high as you dare and the thing still does not pop off, whack the end of the screw on the gear puller with the biggest hammer you can find. If that doesn't do it then cut the hub in half with a hacksaw and weld it back later.

Aside about hammers. When you want to move something, use one great whack with a big hammer. Medium whacks with a medium hammer only move metal around. If any particular whack does not move the parts, many of the same force will not do it, and often will make the situation worse by peening metal around.

If you use WD-40 and then try penetrating oil, the WD-40 residue will prevent the penetrating oil from working. Use penetrating oil first.

Keeping bolts and nuts tight

Summarized from "The Voyager's Handbook" by Beth Leonard:
  • Lock washer.
  • Aircraft locking nut.
  • Drilling and wiring/cotterpin.
  • LocTite or a dab of silicone caulk.
Don't use Loctite when plastic is present (even a nylon locking sleeve inside a nut); it attacks some plastics.

Tapping a hole

From Larry Helber on Yacht-L mailing list:

... Don't forget to get the T-handle for the tap. It is worth it and makes the job of tapping a straight hole much easier.

Tapping a new hole is very simple. Just drill the hole and make sure it is perpendicular. Put the tap in the T-handle and screw it in. [Maybe use some lubricant too.] Every one or two turns back the tap out 1/4 turn. This will break off any burrs that would jam the tap. Keep doing this until the tap is all the way in. Unscrew the tap and you are ready for the next one.

From Eric Thompson on The Live-Aboard List:
When using either a tap or a die, the correct procedure is to turn the tool 1/2 turn, then back to 'break out' the cut metal. Then you proceed to the next 1/2 turn.

After cutting the threads, run the tap or die the length of the work area again to insure clean threads.

When using a tap it is important to have a hole that goes THROUGH the piece of metal, or you must buy a tap specifically designed for use in a 'blind' hole. It will have a much shorter tapered section (and be harder to turn).

Try to keep the tool as perfectly perpendicular to the work as possible. Movement side-to-side while tapping or when using a die will result in loose threads. They may still work, but will result in a weaker fastening.
From Gene Gruender on The Live-Aboard List:
There are 3 types of tap for each size: taper (first), plug (second), and bottoming (last).

If you're going all the way through something, use the taper, run it through until it doesn't cut, meaning you're reached past the tapered part.

As Eric mentioned, if it's a blind hole, you need then to run a plug tap into it, same size, just tapered much less, reaching the full diameter much cleser to the start. After the plug tap, you'd run a bottoming tap, which has almost no taper. It will cut the rest out to the bottom of the hole.

Keep it wet with oil. Motor oil will work. I've drilled and tapped a number of things while out cruising. You can tap aluminum, carbon steel, stainless steel and cast iron with the same taps and system.

As to the size question, in addition to using the drill to fit the tap, taken from the chart, my rule is if a bolt breaks or shears off, drill and tap to a bigger size.

From Chris Smith on The Live-Aboard List:
I can't imagine not having the tap and die set on board. The other item to take up space is my thread restoration tool set. It is basically a set of long taper dies, and a set of hardened steel files that match various thread pitches. This has saved numerous bolts from being scrapped. Let's face it, no matter how well the majority of us prepare, that one odd bolt that you don't have a spare for is invaluable and has to be re-used. The rethread kit has saved my butt more times that I can recall.

From mung on The Live-Aboard List:
Examples of when the Heli-Coil is the right tool for the job (as opposed to tapping a larger hole):
  • Spark plug holes, because you need to be able to get the old thread size back.
  • Head bolts, it's real easy to strip out an aluminum block with a steel bolt. Now, yes, you could enlarge the hole in the head to use a bigger bolt for the size of the tap you would have to use, but then you have one oddball bolt in your engine. Better to put the helicoil in and put the original bolt in, with the added benefit of not being able to strip that hole again because the helicoils are a lot stronger.
  • Sending unit; they don't really come in any size you want, so you want to keep the thread size the same.

Fixing a stripped threaded hole into a casting

From Andrew Bebbington on Cruising World message board:

If you can't either tap a bigger screw, or drill right through and bolt, then as a last resort put two-part epoxy cement (tradename "Chemical Metal" in the UK) into the screw hole, rub the screw in thin grease and screw home. When the epoxy sets, it'll hold all right. Usually it's still possible to get the screw out, especially if it is stainless and has a hex head, but you will be lucky to leave an intact thread behind.

Machining plexiglass

Chris Caswell's "Plastic Fantastic"
"Easy to Make Plexiglas Holders" (bending and machining) by Dennis Angle in issue 2000 #2 of DIY Boat Owner magazine

From Richard on Cruising World message board:
If you are going to do much cutting or machining of plexiglass, ask your supplier to give you cast acrylic rather than the more common and somewhat less expensive extruded acylic. The cast material does not melt when cut. It's a joy to work with compared to the extruded stuff.

From JMott on Cruising World message board:
Try a laminate blade and a jig saw (the teeth set downward) and go very slow to avoid melting the plastic. Apply tape to the base of the saw to avoid scratches. It worked for me. Plexi shops use a hollow-ground band-saw blade. Also to drill screw/bolt holes in plexi, some shops will sell you a bit for $5 to do the job.

From RichardS on Cruising World message board:
A sabre saw with coarse tooth blade running at low speed works well. Too high a blade speed will melt the plastic. A single speed saw can be controlled with a lamp dimmer just like a lamp would be. Lower speed works better for metal cutting also. The cut edges of the plastic can be "polished" with the adhesive used to cement acrylic together. A smooth edge to start with by filing or sanding helps a lot. I leave the protective paper on the plastic for all of the fabrication, taking it off just at assembly.

From Nick Wigen on Cruising World message board:
You should "polish" the edges with a little heat. Enough to melt the sharp corners and edges but not enough to distort the surfaces. It can be done with a propane torch with a little practice. Use some of the scraps and hold the torch well away. Once the rough edges turn shiny that's enough heat. It's not too hard once you get the hang of it.

From Glenn on Cruising World message board:
I have found that using a coarse carbon tipped blade in a table or circular saw just melts the cut and leaves a huge mess. If I move over to a fine-tooth plain steel blade, it cuts it like butter, little chips fly off, no-melting, leaving a nice clean cut surface. Last blade I bought was $6.50 at Home Depot. Well worth the investment.

From Peter Linwick on Cruising World message board:
I have done this for years, cutting new acrylics for hatches. Use a router, double-sided tape your template to the acrylic and rout around it. Flawless operation. No chipping cracking or other problems.

From Steve Studley on The Live-Aboard List:
There is a special plastic cutting blade for circular saws ... it looks like gritty sandpaper on each side. I've used the same blade for about 15 years. The blade doesn't heat the plastic too much. Used it for corian, avonite, lexan, pvc plate and pipe. You can cut outside curves fairly easily, inside curves are a pain. ...

From Ray Mummery on the Morgan mailing list:
There is nothing special about drilling Lexan. If drilling material thicker than about 1/4" it may be worthwhile to use a squirt bottle to use a little water to cool the material, or drill slowly since you can melt the plastic onto the drill bit if it gets too hot; same with Plexiglas or Lucite. Both are somewhat brittle so be sure to have a piece of wood behind the work if drilling in place or beneath if doing on the bench.

Fasten Lexan or acrylic with non-countersunk bolts or screws; countersunk heads will spread and crack the plastic. Put finishing washers under the heads to spread the load. Drill the holes oversize and caulk them. Don't overtighten the fasteners.

Lexan is destroyed (becomes crazed and brittle) by exposure to solvents, including gasoline and acetone. Some people said they had Lexan ports badly damaged by spray or exhaust from mosquito control helicopters.

Polishing Lexan or plexiglass ports

From Phillip Moyer on the IRBS live-aboard mailing list:
I own a Kawasaki Concours sport touring motorcycle and when I bought it it had a cloudy almost milk-color plastic windshield. You could not see through it. I used regular auto rubbing compound to rub it out and it became very clear. That was several years ago and it is still in good shape. Start with the most gentle and if that doesn't do it then work your way up to the next heaviest grade. Mine did well with the least abrasive, but took a couple, maybe three applications with soft cloth rubbing the abrasive on and off with a clean one. Be sure to keep the buffing cloth very clean.

From Denece Vincent on the IRBS live-aboard mailing list:
A couple of other 'cheap tricks' you can try ... a bit of toothpaste will tell you if you can reasonably restore clarity by polishing. If it seems like that works then you may want to invest in a better polish and go for it, but plain old toothpaste will clean and polish a lot of stuff.

I also like to use an "Island Girl" product (on the boat and name escapes me) to rejuvenate clear plastics. Even my badly crazed hatches were much clearer after a good soak in this stuff and the pre-cleaner removed the haze from the side ports easily.

From Rob/Florida Rigging on Cruising World message board:
... clean with soap and water, do not use stuff like acetone or similar cleaning agents, only use specified polishing compounds when removing scratches.

From David Straton on World-Cruising mailing list:
Never, ever, let anyone near Plexiglass (Perspex) with paint stripper.

From Doug on World-Cruising mailing list:
Re: Acrylic (PLEXIGLASS) or Polycarbonate (LEXAN, MAKROLON):

Acrylic has a harder surface but there are polycarb sheet products available with an abrasion-resistant coating applied to the surface. Such as GE's Lexan coated materials, but its only a coating, so once the coating goes ...

The polycarb coated product is very tricky to form without crazing or bubbles showing up on the bends.

Acrylic is fairly easy to bend, form or fabricate and offers nice clear bends. Acrylic also is easily polished, especially edges, where polycarb doesn't polish up well.

Acrylic is more rigid than polycarb; way back in the 70's a lot of dance floors were built from Acylic.

Acrylic is very tough and break-resistant, though notch-sensitive. Hence, cracks can emanate from unfinshed mounting holes or rough edges. Polycarb has a high degree of resistance to any impact, even on unfinished mounting holes or edges, and is very close to unbreakable.

Acrylic is also cheaper than polycarb.

Acrlic has excellent UV resistance. Polycarb products don't, though some are available with a UV coating; again it's just a coating and causes problems in forming.

Drilling fiberglass

  1. Put some masking tape down.
  2. Draw your hole positions on the tape.
  3. Look on other side to see that you aren't going to hit anything.
  4. Tape a plastic bag to other side to catch all of the dust and shavings.
  5. Drill very slowly with an undersized bit in the center of the first hole position.
  6. Look on other side to make sure hole appeared where you thought it would.
  7. Repeat for rest of holes.
  8. Drill holes to proper size. Slowly.
But someone else says: to avoid cracking, drill a "dish" or depression first, with a countersink or big drill bit, then drill in the center of that with a small bit.

To keep nasty fiberglass dust under control, dab a little shaving cream on the area before you start drilling.

Sawing fiberglass: use Fein Multimaster and HSS (high-speed steel) blades. To keep nasty fiberglass dust under control, dab a little shaving cream on the area before you start drilling.

Fiberglass molding article by Bruce Bingham in 11/2001 issue of Cruising World magazine

From Deborah Lloyd on the Morgan mailing list:
We had crazed lexan hatches. Ours are molded, completely lexan with no metal holder and very expensive to replace. For a quick fix a couple years ago that we have learned to love, we put a *very* thin coat of epoxy resin on them, sanded it, then Awlgripped them white. They look fantastic. We weren't sure it would work, but they've held up perfectly. Of course they no longer are see-through. We like that as we live in the tropics (Keys) but that may not be best for your location.

Gelcoat is a smoothly-finished, pigmented layer of polyester resin that is on top of the fiberglass-and-epoxy/polyester hull.

Gelcoat maintenance

SailNet - Don Casey's "Recovering the Shine"

Gelcoat is thin; don't rub it completely off down to the fiberglass.

Keep it hard, smooth, shiny, watertight.

  1. Wash off dirt and grit before it abrades the surface.
  2. Clean off stains (start with mildest possible way: Bon Ami household cleaner (non-abrasive), then rag with solvent, then commercial cleaner, then wax/cleaner, then automotive rubbing compound).
    For oil/grease/tar stain: kerosene or paint thinner, then wash thoroughly with detergent and water.
  3. Repair scratches, dings, etc.
  4. Protect with non-abrasive wax (except on walking surfaces); about 3 times per year.
    Don't use automotive waxes which are formulated for acrylic or alkyd auto finishes; use special fiberglass waxes which fill in pores and screen UV.
    But from Brett King on Cruising World message board:
    Do not use wax or soap on any of the two-part paints, it just makes them dull. Wash with ammonia and water. It will shine for 10 to 20 years. Then sand and repaint.
  5. Every 5 to 10 years, paint.

For faded/dull gelcoat, try these (stop when one works):
  1. Rub with fiberglass paste cleaner.
  2. Rub with automotive rubbing compound.
  3. Wet-sand very lightly with 800 grit sandpaper.
  4. Paint.

Gelcoat repair

From Leon Sisson on Cruising World message board:
First, I read up on fiberglass repair in two or three of the fix-up-your-old-boat books ("This Old Boat" by Don Casey, and "The Boat Repair Manual" by George Buchanan).

I then bought the large gelcoat repair kit from West Marine (later saw nearly identical kit in WalMart for about half the price), an additional qt. of white gelcoat with catalyst, a tube of tint (my topsides are sort of buckskin color), and a qt. of PVA.

I've discovered a couple of things that I don't remember reading much about:

Matching gelcoat colors was really hard for me. It took a lot of patience, and I threw out several batches after screwing up the color beyond recovery. I tinted in approx. 8oz. batches (large enough to complete my repair), and catalyzed in much smaller quantities.

For filler putty, I used tinted gelcoat thickened with Cabosil (coloidial silica?). It worked great.

To get the air-inhibited gelcoat surface to harden, I brushed on PVA mold release just after the surface was stiff enough to resist brush strokes.

At some point in tinkering with the cosmetic appearance of the repair, I paused to have a debate with myself about how many hours I was willing to invest in exchange for what level of perfection on a 20 year old boat. Don't forget to have this discussion with yourself, maybe more than once.

I wet sanded the repairs with 180 and 220, and the entire hull from shear to bootstripe with 320, 400, 600 by hand. I then power buffed with red rubbing compound using a multi-speed 7" disk sander/buffer.

So far I'm really pleased with the results (and modest too!). I'll probably power polish with fine white polishing paste before waxing.

From Roy Miles on Cruising World message board:
Gel coat repair kits are available at marine stores. First sand the base area with fine sandpaper, then clean with acetone on a rag [but Janet aka RavenIV says "never use acetone to clean after you sand, it can compromise the exposed resin. Instead either blow it clear or vacuum the area."]. Don't begin building up the gelcoat patch - first you need to practice getting the color match. No matter what you do, however, it will never be exact. Even if the color gets matched today, six months from now it will slightly discolor with ultraviolet light exposure, making a small change in color. If it's a small area, don't worry too much about it, just do your best. Start blending the pigment with the catalysed resin, put it on a piece of cardboard and let it kick off. When you get a feel for the correct pigment blend, make a little extra and "putty" it on to the affected area. Wipe off the excess while it's still "green" or soft. Then lay a piece of saran wrap on top to seal off the air (unless the instructions of the resin tell you it has a wax additive). When the resin is good and hard, sand it down flush with the surrounding glass using fine sandpaper. Then wet sand with increasingly finer wet-or-dry sandpaper until you get to 600 grit. At this point you will have a difficult time telling it from the original. Then rub a little car wax on top to bring the shine up.

If you use epoxies [instead], you will need to paint over them to protect from further ultraviolet degradation.

From Keven Sard on the Yacht-L mailing list:
There are three big mistakes people make when doing gelcoat repairs.

1) If you rout out the crack you will want to fill the area with some sort of resin based filler. Make sure that when the filler is cured that you de-wax the surface. Sanding to fair it out won't do it. You need to use a de-waxer to take the blush off the repair. If you don't you run the risk of the gelcoat not adhering or curing correctly.

2) Novices will always a) way overfill the routed area leaving a huge hump, or b) way underfill the area leaving a trench. Personally I prefer to see a trench since the hump will undoubtedly be haphazardly sanded and look worse than the original crack. Remember that the filler will shrink slightly. Don't be afraid to back off the catalyst a bit so that you have time to work the area into a nice smooth repair. If you have never worked with resins, make up a batch and practice on a piece of wood or Formica until you get the hang of it. By the way if you have never used a Dremmel tool you might want to practice with that too.

3) The color won't match. Remember that like paint, when the gelcoat cures it will change tint slightly. When I worked in the repair shops we would match the color as best we could, then smear a bit (without catalyst) onto a nearby area and wait a minute or two. This will show you how close you will be to the original color. Don't worry if it isn't perfect; it never is, but the sun and salt will soon take care of that.

With that being said, I'll add one more piece of advice. If the cracks are cosmetic, think about leaving them alone. I know boat owners want their vessels to look pristine forever, but the fact is that cosmetic cracks are inherent in gelcoat. You can't stop them from happening, and if you don't enjoy working with resins and epoxy, and cabosil (micro glass beads) forget about them. Soon you will find that they have plenty of company.

BoatU.S.'s "Fiberglass Repair"
SailNet - Don Casey's "Repairing Gelcoat Cracks and Chips"
Gelcoat repair kits tested in 8/15/2001 issue of Practical Sailor

Resins (epoxy, etc)

From John Dunsmoor:
Polyester resins are laminating resins, they were designed to lay up cloth. A finishing resin is also a polyester resin but has the addition of wax, that will rise to the surface. When you use laminating resin you will notice that the surface remains sticky, this is designed this way so you can lay on another layer.

Epoxy resin is an adhesive, it is made to stick to things. A lot of the time when repair is done epoxy resins are the choice.

Now here is the rub. If I am working on a glass repair, and grind down to fresh material I would normally recommend using polyester resin rather than epoxy resin. I have found that polyester sticks to polyester better than epoxy sticks to polyester. Polyester will not stick to epoxy, if you do a repair in epoxy, then you will have to do every repair on into the future with epoxy because polyester will not stick to epoxy.

New construction. I paint a layer of polyester resin, thinned with acetone on to fresh wood so it sinks in deep. Once this is done the surface is basically a polyester surface and I laminate the cloth onto the wood with no problem, never had a delaminating problem with this method if the surface was fresh.

Epoxy resin is more expensive. I would not use WEST System epoxy. I would drive to Fort Lauderdale and use Fasco epoxy. I have used both on repairs and Fasco worked better than WEST. Joe's Auto Marine sells Fasco, I am not sure who else does.

Be careful of high solids epoxies like Steel Flex, they can be very very tough to sand. Bondo is not a marine product and should not be used. It will suck up moisture like a sponge.

If you need to do some filling on a polyester repair, just mix some resin with cabosil or micro balloons and you have something the consistency of Bondo.

Same with epoxy, mix with the same fillers and spread away.

Progressive Epoxy's "Marine Epoxy Home Page"

From people on The Live-Aboard List:
Instead of expensive filler from WEST/Gougeon, use diatomaceous earth (used in swimming-pool filters; sands easily), powdered silica, cab-o-sil, or pulverized lime (very hard to sand).

Electronics repair

From Rusalka Mist:
... [Radio] soon caught a direct hit from a pint of sea-water coming in the main hatch. It did not work again during the crossing.


Believe it or not, all electronic circuits are completely waterproof. It is the conductivity of water, especially sea-water, sitting across the connections that makes them malfunction. The corrosive powers of sea-water can also do terrible damage if left in place for more than a few days. I took the plastic case off the machine off and ended up with three circuit boards (a computer, the radio receiver and the cassette machine), a buzzer and the loudspeaker, all interconnected and sitting in the washing-up bowl. I washed and re-washed the whole lot in several changes of cold, fresh water, washed and oiled the telescopic antenna and the battery terminals, and rinsed out the two halves of the plastic case. When I was convinced that there were no more salt crystals lurking anywhere, I put all the parts around the cockpit seats in the sun and carefully began to dry everything with clean, absorbent kitchen paper. When reassembled and then left overnight to dry completely, it all worked again perfectly.

This seems very bold at the time, "Electricity and water don't mix" we are told. I have done this to many pieces of sensitive electronics including Autohelm autopilots, digital watches and cameras. It usually works, if the corrosion has not gone too far and if you are careful not to touch any of the delicate adjustments. All you have to do is remember how to put it all back together again when it's dry!

From article by Clark Beek in 7/2003 issue of Sail magazine:
  1. Check obvious things: power, wires, fuses, switches, corrosion, connections.
  2. Take apart, separating out printed circuit boards.
  3. Check obvious things again.
  4. Look for cracked soldered joints.
  5. Wash the circuit boards; don't wash batteries, motors, speakers or displays. Wash with fresh water, scrub with water and a little dish soap, rinse thoroughly.
  6. Dry very thoroughly and for a long time. Also sun-dry or put in oven at very low temperature.
  7. Put it back together and try it out.

Stainless steel

Stainless steel maintenance/failure article by Ralph Naranjo in 3/2001 issue of Cruising World magazine.
Stainless steel article by Steve D'Antonio in 6/1998 issue of Cruising World magazine.
Principal Metals (data on more than 5000 materials)
"Metal Corrosion" article by Mark Smaalders in July/August 2001 issue of Good Old Boat magazine
"Drilling Stainless" article by Wayne Redditt in issue 2001 #1 of DIY Boat Owner magazine.

Keep stainless steel clean (rust-free), and polish it frequently.

From John / Truelove on The Live-Aboard List:
> 304 or 316 stainless: I am getting ready to
> purchase the steel for my solar panel rack and am
> wondering what the real-world difference is in
> the corrosion resistance of these two alloys.

I think 316 is the stuff to use. I made mine out of 304 7/8" ss tube. It supports four 75 W panels. It's fine, but it rusts badly, just as the pulpit rails do. If I do it over I'll use 1" passivated 316. My external chainplates are passivated 316, and they *never* rust, but I'm always after the railings.
From Bruce Bowman on The Live-Aboard List:
Whatever you use, make sure the fastenings and the structure are the same material. Mixing materials, even differing grades of stainless, can invite corrosion in something that would otherwise be OK.

Summarized from "Rigging Lessons" article by Tom Zydler in May/June 2001 issue of Ocean Navigator magazine:
Type 316 stainless steel is vulnerable to "stress corrosion cracking"; don't use 316 for chainplates and other fittings. Use other stainless steel alloys, or Monel, which are "immune to stress corrosion cracking".

Mostly summarized from stainless steel article by Steve D'Antonio in 6/1998 issue of Cruising World magazine:
  • Galvanized steel: "hot-dipped" usually has 3 mils of zinc; electroplated usually has 1.5 mils.
  • 302 and 303 SS: crevice-corrodes freely; rusts from saltwater; never use below waterline.
  • 304 SS: somewhat greater corrosion resistance than 302 and 303; rusts from saltwater; never use below waterline.
  • 18-8 SS: surgical stainless; similar to 304.
  • 304L SS: better than 304 for welding.
  • 316 SS: much greater corrosion resistance than 304; 85% as strong as 302 or 304; use above water; if for shaft protect with zinc.
  • 316L SS: better than 316 for welding.
  • 321 and 347 SS: good for welding; use above water.
  • Aquamet and Aqualloy: SS's for shafts; corrosion-resistant and weldable but expensive.
  • SS needs oxygen to remain stainless.
  • Welding SS (other than "L" versions) creates zone of mild steel around the weld.

From Mark Mech on The Live-Aboard List:
The key to drilling stainless steel is first: a good bit, don't even attempt it with cheap bits.

The second most important thing is to drill at a constant speed that doesn't overheat the metal. This is the most important reason to lubricate (you could use water); if you overheat the metal by either going too fast or too slow, it will "work harden" and you will toast the bit. If it is a deep hole, you may not get the bit back because it will gall in place then break off or get REALLY stuck.

So keep it moving, keep it wet, and keep it sharp.
Also: "use Moly-Dee cutting fluid".

I enlarged some holes in stainless steel: bucket of water to cool work-piece and bit after every 15-30 seconds of drilling, vegetable oil as cutting fluid, and keep a steady feed pressure of the bit on the work-piece.

From "Drilling Stainless" article by Wayne Redditt in issue 2001 #1 of DIY Boat Owner magazine:
  • Use low speed.
  • Feed bit into material as fast as it will go; press hard. If using a bit smaller than 1/4", you should press hard enough to make the bit flex.
  • Center-punch to keep the bit from wandering when starting.
  • Use lubricant.
  • Don't stop or slow down until hole is finished.
  • Best bits are HSS jobber bits, not titanium oxide coated or special tip grind.
  • Drill pilot holes.
  • Using a drill press is best.
  • If bit turns blue while drilling, it's turning too fast or is damaged.

Epoxy onto steel

  1. Clean the metal.
  2. Sand with coarse sandpaper.
  3. Thin coating of epoxy.
  4. Sand again while epoxy is still wet.
  5. Put other piece onto epoxy.


Good articles in May/June 2000 issue of Good Old Boat magazine

From articles in May/June 2000 issue of Good Old Boat magazine:
  • Much of the "bronze" sold technically is brass (contains zinc, and often lead). Real bronze is copper and tin. Brass is easier to machine.

  • Stainless steel is stronger and tolerates aluminum, but bronze doesn't rust or crevice corrode.

  • Deterioration of bronze is signaled by white powder or flaking metal.

  • Many different alloys of bronze: silicon bronze (alloy 655), manganese bronze, HT bronze, etc.

  • Many different alloys of brass: free-cutting yellow brass (alloy 360), a red brass (alloy 230), etc.

Bristol Bronze


From Yahoo Answers:
The color terms yellow and red are American terms referring to the composition of the brass. Yellow brass is 33% zinc and 67% copper. Brass goes from dark reddish brown to light silvery yellow depending on the amount of zinc. The more zinc the lighter the color. Red brass is really not brass as it is an alloy of copper, zinc, and tin. It is also called gunmetal.

Any brass whether yellow, red, whatever, will be fine for a fuel system. You should always uses silicon bronze for below-water fittings and no brass.

No one that I have ever seen makes bronze nipples. Bronze is cast and brass pipes can be extruded. Bronze does not extrude well into pipe form thus no bronze nipples. There is no need for either red brass or bronze in a fuel system. Moeller (used to be Tempo) is one of the largest suppliers of marine fuel fittings and they are all brass. ABYC does not specify anything other than brass either.

There are two kinds of brass on the market, yellow brass and red brass. Yellow brass is made from a variety of metals such as zinc, tin etc. This gives the brass a yellow appearance and has a life expectancy of somewhere between 10-25 years. However, red brass when compared to yellow brass has a reddish look due to the high copper content (80-85%) and has a life expectancy of 50-100 years. Note: Life expectancies assume clean water and environmental conditions. Harsh water and/or environmental conditions may shorten the life expectancy of brass products.


WWA WoodSampler (pictures of woods)
Windsor (detailed info about woods)

Fine Woodworking magazine (good articles/tips online)

Machinable modern materials, that won't corrode like metals or woods

  • StarBoard
    Can't glue or caulk or seal an edge against it, except maybe with special glue and tools from manufacturer.
  • PlasTEAK
  • UHMW plastic.
  • Garolite / G10.
    Easier to cut/sand/paint than metal/wood/fiberglass, but must paint to protect it from UV.
  • Flexiteek
  • Wood/plastic composites: Trex, ChoiceDek, TimberTech
  • Arborite ? (Or maybe it's a veneer over composite, like Formica ?)

Some of these materials (such as StarBoard) are too soft/porous for applications (such as galley counter) where they might get chipped or stained.

From Mike on Gulfstar Owners mailing list:
Be careful with StarBoard out in direct sunlight. UV degrades it over time and any stress points will split. I installed PVC (StarBoard) handrails instead of teak. After 4 years on deck, they all cracked at the screw points.

Manufactured fibers

(Summarized from article by Hugh Horton in Epoxyworks #16 Fall 2000)

Strong in one direction only.
A&P Technology
  • Carbon fiber: strong in tension, strong in compression, fairly easy to abrade and shape. But fibers are noxious, edges are sharp, dust is irritating and noxious, black color gives heat buildup.

  • Kevlar braid: strong in tension, weak in compression, hard to abrade and shape. Easy on the skin.

SailNet - Tom Wood's "It's Winch Servicing Time"
SailNet - Tom Wood's "Keel Shield"
"Wooden Rails Made Easy" article by Gary Grinnell in issue 2000 #3 of DIY Boat Owner magazine.

Batteries not holding a charge

  • Bad charging system voltages ? Bad float voltage ?
  • Bad cell in battery ?
  • Unequal acid gravities in cells of same battery ?
  • Loose/corroded wires/connectors/switches ?
  • Intermittent load ? Disconnect battery from all loads and see if it stays charged.
  • Do load test of battery.

From John Dunsmoor:
> I'm confused about when I should use grease,
> spray WD-40, or teflon lubricant.
> For example, my dinghy davits have sheaves in them.
> What should I lubricate them with ?
> How about the blocks in my running rigging ?

WD-40 is a good all around spray around saltwater, more of a rust preventer and general light lubricant, but not the same as a grease. Grease is a heavy lubricant that sticks to parts, like wheel bearings and winch bearings. But not as something you would put in a transmission per se. A gear box needs a lubricant that flows, so does an engine.

Most running rigging, sheaves use no lubricant, nor should they. These are made with Rulon or Nylon bearings that are self-lubricating. If you were to use grease, teflon or waterproof, then what happens is that the "grease" gets full of grit, dirt, salt crystals, grime and this forms an abrasive and destroys the bearings. Mostly with things like running rigging blocks and such, a good dose of fresh water once in a while to keep them clean is the best bet.

Davit sheaves ... depends whether or not they have bearings, bushings or what. The best bet is to know what the manufacturer recommends.

From Rob Homan on the Morgan mailing list:
Subject: One way to fix a polyethylene water tank.

Yesterday I was talking to one of our fellow sailers in a boating store, and he said that he had worked in the RV industry for quite a while and we had been discussing my dilemma with my water tank, and the fact that it appeared that there was no way to buy an OEM replacement.

He suggested that I go to "Camping World" and get a Polyethylene Plastic Welding Kit. Well, I did. It is named just exactly that. It is manufactured by Kennedy's Enterprises, PO Box 82544, Bakersfield, CA 93380-5400.

I "welded" my tank today using their product, and below I will describe the process:

My tank that resides below the forward V-Berth had a crack at the rear center bottom behind the outlet nipple on the tank. The crack was about 3 inches long and was one that allowed a very slow leakage of water.

I cleaned up around the area and then took my Dremel tool with a very small router bit and followed the crack routing a groove into where the crack was. I drilled stop holes in both ends of the crack. I cleaned all the bits and pieces away from the area and then took the "welding rod" and laid it into the groove and started heating up the rod to melt it into place with a rather hot "heat gun". I followed the directions on the package which called for melting the rod an inch at a time. You have to let it cool a little and do this while holding this very still. The objective is to get the welding rod as deep as you can into the crack. During this whole time you have also been warming the surrounding areas of the tank, and so then you take and heat up the larger plastic stick melting it and letting the melted plastic roll over where you welded in the smaller rod. The second stick provides a seal that covers over the work area and closes up any tiny holes that may be present.

The whole process didn't take but about 30 minutes after I pulled the tank out and found the crack in the tank. I have to warn you ... If you choose to use this product, do not touch any of the area you have worked on for a couple of hours ... this stuff really holds heat and it will stick to you. I found out by being too curious.

I'm going to let the tank sit over night and "cure", then tomorrow I'm going to put a second "sealer coat" on it and let it cure again. Then I'm going to put it back in its molded cradle and fill it with water ... and then I'll come back and let you know if this product works as it is supposed to.

Repairing plastic: maybe use fiberglass cloth and G/5 Adhesive from Epoxyworks.

Diving on your boat

Summarized from "Below the Waterline" article by J. J. Stives in July/Aug 2001 issue of Ocean Navigator magazine:

Sometimes, it is best not to dive on your boat. Alternatives: wait for better conditions (daylight, calm, etc), wait for help, get a tow, get professional diver, get boat hauled out.

It may be best not to dive on your boat if you haven't used your SCUBA equipment in years, if you're not in good shape, etc.

Planning list for a dive:
  1. Survey problem from on board as much as possible.
  2. Pick tools (minimum: wire cutters, diagonal cutters, knife, pliers, screwdriver).
  3. Decide how to enter and exit the water.
  4. Will boat be safe while diver is in water ? What are winds, currents, hazards, depths, sea room ?
  5. What will happen when problem is solved ? Will boat sail/blow away from diver ?
  6. Consider using dinghy as platform for a partner and tools.
  7. What are water conditions (temperature, visibility, depth, current) ?
  8. Decide level of clothing diver will need (minimum: hand and foot protection).
  9. Prepare gear.
  10. Prepare tools (all should have breakaway lanyards).
  11. Hook up safety lines (diver should be able to cut them if needed).
  12. Check for traffic, display diver down flag, broadcast alert on VHF, light up the boat.
  13. PFD's on everyone; BC on diver.
When in water:
  • Watch out for motion of boat.
  • Watch out for recoil when lines are cut or propeller is freed.
  • Nets, sheeting, fabric, fishing line are very dangerous; don't get tangled.
  • First, evaluate the problem, inform others of problem and plan to solve it, get agreement. Then execute the plan.

From Doug Barnard on The Live-Aboard List:
Re: Securing shelving to fiberglass hull:

[... epoxying wooden blocks to the hull and screwing shelving unit to these ... ]

For a first-timer, I'd suggest going with West Systems, and getting their book. It's available at most marine stores. At about half the price, try the Basic No-Blush at . You can still use the West methodology, just follow the different mixing instructions. I wouldn't go with the cheaper polyester resin, as it's tough to use, very temperature-sensitive, and will fume you out of the boat as you apply it.

For a super-strong installation, get some of West's microballoons (or use very fine shop sawdust, if you're cheap like me) and mix up a peanut-butter-like paste. Use it to glue the block to the hull, and apply with a Bondo squeegee to make a nice rounded fillet between the hull and the block. Still want it stronger? Apply some fiberglass cloth over the fillet, and give it a few coats of epoxy. Use disposable bristle brushes and surgical-type gloves. No air bubbles allowed!

I've had good luck (so far) with gold-anodized drywall screws, much cheaper, easier to use and stronger than solid brass screws. We shall see about how well they hold up, but I'm in a very dry climate, YMMV. They're so cheap, I can always replace them with solid brass, and only be out a few bucks.

Probably the easiest way to mount the shelves is to attach the blocks to the shelves first, goo them up, and then wedge the whole deal into place with whatever's handy. After the epoxy's kicked off, but before fully cured, careful unscrew the shelves and remove. You can then scrape away any extra epoxy, much easier (and cleaner!) than sanding. Mix up another batch, and do your fillets. You should treat the wood (paint, varnish, whatever, at least Thompson's Water Seal) fully before re-attaching your perfect-fitting shelves.

From SailNet - Tom Wood's "Mounting Deck Hardware":
"Consider lashing or taping a new piece of gear in place and using the boat that way for a week before bolting it down permanently."

From Sandy Gurnell:
To avoid dropping a screw into the bilge, tie a thread to it. Screw it in most of the way, then cut or snap the thread.

See Periodic Maintenance section of my Lists for Operating a Boat page.

"Hit on it until it breaks, then back off one hit."

To-do list