Author: hamilton_adm

Safety Requirements for Recreational Boats

As the owner of a recreational boat, you are required to carry aboard your vessel a minimum of safety equipment. Most of us go about our boating experience giving very little thought to the possibility of misfortune, and rarely are our experiences anything but positive. But remember the motto: Be prepared!

As vessel owners we are subject to the requirements placed upon us by our state and federal governments regarding the operation of, and the equipment we carry on, our boats. Some might feel this is a case of Big Brother being involved more than they would like but the reality is that safety items we are required to carry on board are usually only the minimum. Sometimes when a tragic situation does occur, vessel operators wish they had gone beyond the minimum. These requirements are for our own good.

So, what exactly are we required to carry on board? Certainly, the size and type of vessel has some impact on that decision. Here is the list, made as convenient as possible.

SAFETY EQUIPMENT LIST

  1. Lifejackets (PFD- personal flotation device). One properly sized, U.S. Coast Guard (USCG) approved PFD for each person on board. These must be in serviceable condition, easily accessible, and are a requirement for ALL vessels. Boats 16 feet and longer, except canoes and kayaks, must also carry an additional PFD called a throwable (Type IV) device. Type V PFDs (inflatable) must be worn at all times aboard to be considered a PFD; wearers must be 16 years of age, or older.
  2. Visual Distress Signals. A minimum of three signals for day use and three signals for night use must be kept on board. We suggest pyrotechnic devices (flares). There are red signals that qualify for day/night use. We recommend these. Signals must be currently dated (they have a 3-year lifespan). If you venture more than a few miles from shore, orange smoke signals and rocket type flares make a smart addition. Save your outdated signals in a separate location from the currently dated ones, so you will have back-up signals.
  3. If your boat is over 16 feet you must carry Visual Distress Signals. Exceptions are: vessels on lakes (except the Great Lakes), sailboats under 26 feet without propulsion machinery, manually propelled boats, and boats participating in organized events—for these vessels VDS are not required. Non-pyrotechnic devices and electric distress lights may also be acceptable under certain situations.
  4. Fire Extinguishers. There are many types of fire extinguishers and the regulations are rather complicated. Essentially, if your boat has an engine or a cooking system aboard, you are required to have the minimum compliment of fire extinguishers. These must be USCG approved Marine devices. If your vessel has much wood aboard be sure the devices you carry are also rated for wood/paper fires (“A”), not just gas, oil, and grease (“B”) or electrical (“C”). There is always confusion here as the sizes of fire extinguishers also use the letter “B”—as in B-I, B-II, to indicate the volume of suppressant. Fire extinguishers must be mounted in their brackets, have operating gauges (if any), must be in good physical condition (no rust, dents, etc.), and have seals/tamper indicators in place. Those with indicated weights, should be weighed to verify no propellant or suppressant loss. Dry chemical extinguishers should be inverted and tapped periodically to keep the powder from compacting. Vessels less than 26’ require one B-I; 26’ to 40’ vessels require two B-I or one B-II; 40’ to 65’ require three B-I or one B-II and one B-I. Think about it, why would you not have more than the minimum requirement?
  5. Ventilation. Boats that use gasoline for propulsion, mechanical power, or electrical generation are required to have adequate ventilation. This narrows down to permanently installed engines in enclosed spaces and the gasoline storage tanks that are adjacent to, or vent into them. Adequate natural ventilation and/or a powered ventilation system is required to remove the toxic, potentially explosive fumes. The regulations are complex, but if your boat was built after August 1, 1980 it must meet these requirements. A good rule of thumb is to install a powered ventilation system so there is good ventilation in all areas of the boat where gasoline fumes may linger, if one does not presently exist. Outboard motors are exempt.
  6. Backfire Flame Control. Gasoline engines installed in a motor powered boat after April 25, 1940, except outboard motors, must be equipped with an acceptable means of backfire control. A backfire flame arrestor must be secured to the air intake with a flame-tight connection and must be USCG approved or comply with SAE-J-1928 or UL 1111 standards and be marked accordingly.
  7. Sound Producing Devices. Navigation Rules require that sound signals be made under certain circumstances. Recreational vessels are required to carry sound producing devices as follows: 12 meters (39.4 feet) or more: whistle; 20 meters (65.5 feet) or more: whistle and a bell. An air horn or an electric horn counts as a whistle. Currently these requirements are the same for Inland and International Waters.
  8. Navigation Lights. Refer to the Navigation Lighting section in our current catalog. As the regulations are rather complex, suffice it to say that for sailing vessels under 23 feet (7 meters), if lights can’t be shown, then a handheld flashlight with white light must be shown in time to avoid a collision. Vessels under oar or paddle power may also use a white flashlight, if navigation lights are not part of the vessel’s equipment list. All other vessels should exhibit proper lighting as required.
  9. Other Requirements. If your vessel has a toilet it must have an operable Marine Sanitation Device (MSD) Type I, II, or III. Vessels 26’ and longer must display a Garbage Placard. Vessels 26’ and longer with a machinery space must display an Oil Pollution Placard. Vessels longer than 12 meters (39.4 feet) operating in U.S. Inland Waters must have a copy of the Inland Navigations Rules aboard. U.S. Oceangoing vessels over 12 meters (39.4 feet) with a galley and berthing, or engaged in commerce must have a posted Waste Management Plan on board. Vessels with propulsion machinery must be either State Registered or Documented with proper numbers correctly didplayed. Documentation papers or registration papers must be carried aboard.
  10. Common Sense. Surprisingly, there is no requirement that a communications device be carried aboard recreational vessels under 65.6 feet (20 meters). Common sense dictates that every vessel traveling more than a mile from shore carry a marine VHF radio—either a handheld or a fixed mount. If you do have a VHF radio aboard there IS a requirement to monitor Channel 16 or Channel 9, whenever the radio is powered up.

EPIRBs (Emergency Positioning Radio Beacons) have been around for over 20 years. The technology has advanced tremendously and the system has proven itself thousands of times. Some versions incorporate a GPS to pinpoint your location. If you are going offshore, especially in colder waters, or making a passage an EPIRB is the cheapest insurance there is. Consider investing in one.

Paint Help/How to Links

Information Provided by Hamilton Marine

Information Provided by Pettit Paint

Information Provided by Interlux Paint

Information Provided by Sea Hawk Paints

Topside Painting

Safety

We’ve learned a lot about how Volatile Organic Vapors (VOC’s) affect the human body over the last decade, and none of the news is good. Only a few years ago it was thought to be OK to work all day bathed in fumes, wash our hands in paint thinner, and go home at the end of the day. Now we know we must protect ourselves with disposable gloves and vapor-absorbing filters, and wear coveralls and head socks to keep dust and spatters off our bodies. If you are about to begin a project and these things are unfamiliar to you, check them out in our catalog or web site. Get a hold of a good article or book on boat painting and learn from it. Follow this simple rule of caution: If you can smell it, you need more fresh air or the next higher grade of respirator mask.

Help is Available

We at Hamilton Marine, along with our paint and paint supplies manufacturers, want you to get the best possible results from the products we carry. You will find basic hints here in this article. For more specialized tasks, see the selection of books listed in our catalog or available on our website. Several of our major paint suppliers list phone numbers on their web sites that you can call during business hours for technical assistance. As always, feel free to contact us here at Hamilton Marine at 800-639-2715.

Preparation

More than likely, you’ve encountered the advice…whatever imperfections lie on the surface to be painted will only be enhanced by painting…so, get the surface right before you paint. Experienced painters will tell you that if the surface does not feel smooth to your hand, putting another coat on top will not fill in the surface imperfections or improve it. Careful and thorough preparation from the start and during each successive step is the secret to professional-looking results. And preparation, in many instances, is just another word meaning having the right supplies on hand and knowing how to use them correctly. You need an abundant supply of the proper grades of sandpaper, the exact thinner and wiping solvent recommended by the manufacturer and lots of clean rags to make the job go smoothly and to help you achieve a superior final result.

Primers and Undercoats

Paint chemistry has become enormously more complicated since the days when all that was required was to grind up some pigment and mix it with oil and thinner. Today’s paints are far brighter, tougher and longer lasting than those of even a few years ago. And today’s paints often require special surface preparation and specific additives to get the results you desire. So read the instructions, on the can—or printed literature, if available– making sure to have exactly the right products on hand to complete the step-by-step process. You can always find people around boatyards who will tell you to take shortcuts, like substituting materials or painting when it is colder or hotter than recommended. Unless you are sure they are correct, why be part of a “lab” experiment?

Choosing the Right Paint

One-Part Polyurethane: The most popular topside and deck paint choice, this is the one we recommend most highly. We consider it ideal for do-it-yourselfers who can achieve near-professional results with a brush or roller (or both, as with rolling and tipping). Even though it’s not quite as hard or durable as two-part polyurethanes, many professional painters find it close enough in appearance that they prefer it to all other enamels.

Alkyd Enamel: This traditional oil-based paint is easiest for the amateur to apply using a brush. Still very popular, it is more compatible with underlying surfaces, more economical and doesn’t require as much fuss as polyurethanes; however gloss and color retention are lower. For the traditionally planked wood boat, alkyd enamel is a good choice for dealing with the expansion and contraction of wood. Also, its oils are chemically compatible with the wood’s natural oils.

Two-Part Polyurethane: This is the hardest, highest-gloss, most durable paint available. Some can be brushed or rolled but others must be sprayed. More attention is required for surface preparation and priming than for one-part polyurethanes, and they are generally more toxic, especially when sprayed. Some two-part polyurethanes will “lift” oil-based paints, so check for compatibility with the paint that’s now on your boat. Most manufacturers recommend application by professionals only. If you decide to go it on your own, visit the manufacturer’s website and follow their advice to the letter.

Paint Application Tips

Remember cleanliness. Between each coat, oil and dirt residues must be removed. Refer to the manufacturer’s recommendations. Some prefer dishwashing detergent and water; others wipe down with a compatible solvent wash. Plan ahead so ample drying time is allowed after each step.

When applying paint over epoxy, allow the epoxy to cure at least 7 days (10 days is better) and remove the amine blush from the surface of the cured epoxy…even non-blushing epoxy. Warm fresh water will do this just fine– be sure to allow it to dry. Compatibility issues still pop-up between paints and resins even when these steps are followed.. If you have any concerns, no matter how small, consult with both the epoxy maker and the paint maker.

Don’t apply paint when it’s windy, wet, foggy, snowing, or late in the day. Forming dew can turn a high gloss paint job into a satin nightmare. Waiting an additional day may save you from re-doing a failed paint job.

Heed what the manufacturer says about the temperature at which the paint can be applied. Most manufacturers suggest a 50°–80°F range. Professional painters can compensate for temperature variations and can change a paint’s drying characteristics using thinners and reducers, but that’s risky business for amateurs. Drying may also be slowed by a relative humidity above 65%.

Wear protective clothing, especially respirators and eye and hand protection, when dealing with toxins and strong chemicals. Provide adequate ventilation, and keep all products away from sparks and open flames. When the job is complete, wash sanding residue and solvents off of you immediately.

Read the instructions on the can again. It sounds simple, but it can prevent you from overlooking a small tip that can make a big difference.

Good brushes are like good shoes and shirts: they may cost more initially, but they are a pleasure to own, last longer and work better than cheapies. Use less expensive brushes for projects with resins and bottom paint and where the final finish does not matter.

Use Fine Line tape to ensure sharp, clean divisions between colors. Although more expensive, its thin profile, sharp edges and better adhesion will do a much better job than other tapes.

Stir—do not shake—enamels. Bottom paints need to be shaken because their heavier contents settle, but shaking topside paint causes bubbles that hinder the application and cause blemishes in the final finish.

Clean the surface with a tack rag to remove the last vestiges of dust and residue immediately prior to painting. If you use a solvent wash, allow it to evaporate completely before painting.

Applying the Paint

  1. Paint will hide underlying color, but not texture. How many coats and what type of paint you use will be important. However, the use of sealers, sanding surfacers, putties, and sandpaper will have as much to do with your final results. Be aware of proper application techniques and cure times for the products that will be applied to the surface to be painted.
  2. Always observe appropriate drying times between coats of paint. This means paying close attention to labeling on cans and manufacturer’s instructions.
  3. All surfaces should be lightly sanded between coats, and especially prior to applying the finish coat, unless otherwise recommended by the manufacturer. Sanding smoothes-out the surface, fills-in small blemishes, and sets-up the surface for proper adhesion of the next coat. We recommend hand sanding, lightly. Consider a sanding board for large faired surfaces. A power sander is not recommended as it can load-up the sandpaper very quickly, polish the surface, and generally make a mess very fast.
  4. Multiple thin coats are far better than one or two thick coats. However, applying a film that is too thin may result in uneven gloss or visible brush marks, so always strive to get at least good coverage. For the first coat this may not be possible, so plan on at least three coats for your application.
  5. Brush or roll paint in one direction without interruption. Paint should be spread evenly and as quickly as possible to a uniform film thickness. Rolled paint will generally leave small surface bubbles or footprints. If you desire a smooth, high gloss surface, immediately draw a dry brush at right angles to the direction you rolled on the paint (if you rolled up and down—then drag the brush from right to left, for example). Work in small areas…maybe two feet wide, from gunwale to waterline…and work fast, not going back over your work. New paints applied this way (rolling and tipping) dry to tacky very rapidly; going over the area you just painted will likely damage your work.
  6. When you notice a thin spot or a dry spot, resist the temptation to go back over it. Wait for the next coat to cover it completely.
  7. If spraying is the desired application method, please refer to the manufacturer’s instructions. A top-quality spray finish requires proper materials, lots of painting experience and professional equipment. Most spraying is done by maintenance yards and experienced professionals, not by recreational boat owners. Spraying creates a myriad of environmental and health hazard issues, as well.

Cleanup

You can reuse leftover paint in a can if you cover the surface with a layer of plastic wrap to prevent a skin from forming—however, that’s a bit messy. You can also seat the lid of the can firmly with a rubber mallet or other soft instrument and store the can upside down (displacing the air to what was the bottom of the can.) Also, Hamilton Marine offers a nifty oxygen-blocking product, called Bloxygen, that is used to displace the air in a can, replacing it with nitrogen, effectively preventing paint and varnish from skinning-over in the can. It comes in a small, pressurized container about the size of a spray paint can.

Clean your brushes in used paint thinner that has been left undisturbed in a can. Thinner allows paint solids drop to the bottom of the can and can be reused many times. Use clean thinner for the final rinse. Wash brushes in warm soapy water (dish detergent works great) and rinse out, then wrap with a paper towel to help keep the bristles aligned. You can also keep the brush suspended in clean paint thinner, in a covered container—ready for the next use.

Clear Wood Finishes

Entire books have been written about the proper surface preparation for and application of clear wood finishes—this brief review, naturally, can only touch some of the highlights. You may wish to not only protect but also enhance wood’s natural beauty with oils, varnishes, or other clear sealants. A good finish applied to the wood on your boat will provide a barrier to protect against the elements that will attack the wood during the season–sea, rain, wind and sunlight. Deciding which to use is often confusing…frequently, appearance plays a big part in deciding what to apply.

Surface Preparation

Different woods will require variations on proper surface preparation prior to the application of the finish. That said, basic preparation includes getting the surface smooth and clean– to allow for a pleasant looking base, but also to allow the finish to adhere properly to the wood. This usually includes:

  1. removing the existing finish
  2. bleaching faded or oxidized wood
  3. removing natural oils from woods such as teak (alcohol or acetone may be used—but, beware the extremely toxic nature of the latter)
  4. sanding the surface as desired (sanding raises wood grain—so, application of a sealer or thinned product when applying varnishes would be a good idea—requiring a sanding again, prior to application of further coats.)

Varnish

Varnishes have long been the traditional clear wood protector. They are generally made up of oil, solvents, resins, dryers, thinners, and other additives. By varying these ingredients, and by adding UV inhibitors and other proprietary ingredients each manufacturer’s varnish will have different characteristics. Although in many respects they may all be quite similar. Varnishes can have a gloss or a satin appearance. They can be extremely hard and durable, and can vary in color from clear to dark amber. One very good idea is to cut the varnish for the first coat on bare wood by as much as 50% with the recommended thinner. This may sound a bit overboard, but it actually allows that first coat to penetrate deep into the wood’s grain, allowing for an exceptional bond between the wood and subsequent coatings of varnish. Varnishes generally require at least 6 coats…10 coats is not uncommon. Satin finishes are usually applied only for the last coat on exterior surfaces. The two-part varnishes are polyurethane based. They are even tougher and longer lasting, and can frequently be applied two– some types three– coats per day, saving time. Examples—(Conventional): Epifanes Clear Gloss Varnish, Petit 1015 Captain’s Varnish, Interlux Original Varnish, and many more. (Two-part Varnish): Bristol Finish, Interlux Perfection Plus, Epifanes Poly-urethane Varnish, and others.

Oils

Wood or Teak Oils will penetrate more deeply into the wood fibers and maintain the original look of the wood better than other finishes that are simply surface coatings, but oil has a shorter lifespan than varnish or synthetic finishes. Oils range in color from clear to dark brown. As with any wood finish, multiple coats will result in a more uniform finish and greater longevity. Oil is usually the easiest to apply– but, as with any wood finish, it requires some basic preparation for the best results. Clean, sanded teak with several coats of oil can provide 3-6 months of protection. There are several varieties of wood and teak oils to choose from—all seem to provide satisfactory results within the 3 to 6 month lifetime of this product. Examples: Deks Olje (#1 is a Satin; #2 is a Gloss which is similar to a varnish, in some respects. More coats will last considerably longer than traditional oils); Various Teak oils, and Tung and Teak oils.

Synthetic Wood Finishes

(Sealers) Synthetic Wood Finishes become more popular each year. They can be as easy to apply as an oil finish and they have almost the same durability as a varnish, yet can be somewhat simpler to refinish when the need arises. They are an easy-to-apply alternative that offers good durability and a good-looking finish that offers a different (slightly cloudy) appearance than either varnish or oil. These are available as tinted or clear finishes. These finishes require basic initial surface preparation, and application is essentially the same as the first coat of a varnish. After that first coat, multiple coats can be applied easily with no surface preparation. Maintenance coats are much simpler than varnish (hence the appeal!), generally requiring only a cleaning of the existing finish and re-application of a new coat of finish. If there are damaged spots, the technique generally used is a touch up of the damaged area, then an application of finish to the whole piece. Examples of Synthetic Wood Finishes includes: Armada Wood Finish, Cetol Marine Finish, Epifanes Rapidcoat.

Resources

Some books worth checking into for more detailed information include: WoodenBoat’s Painting & Varnishing (edited by Peter H. Spectre) Sailboat Refinishing by Don Casey (McGraw-Hill) Also, read the labels on the finishes you are considering—oftentimes there is a wealth of information there.

Blisters & Barrier Coats

Gelcoat Blisters

When fiberglass boat building started, very little thought was given to the possibility that the fiberglass or the tough gelcoat surface might eventually break down. Gelcoat was developed to protect the fiberglass structure and was thought to be an impermeable layer that would keep the underlying resin and fibers dry for the life of the vessel.

As time has borne out, blisters (osmotic blisters) appear on some boats; sometimes quite quickly, and in other vessels only after many years of use. Water in warmer climates seems to encourage them (with the proportional longer boating season) and the builder’s specific choice of resin may also help deter them. The fact is, to date, we can’t accurately predict when a blistering problem might occur.

To understand more about blisters here is a quick review how the typical fiberglass boat is constructed. First, mold release wax is sprayed onto the inside of the mold, then the layers of gel coat, a specially formulated pigmented polyester resin that gives the boat its color and smooth exterior finish, are sprayed on. Laminated above the gel coat are layers of fiberglass, usually in the form of chopped-strand mat and woven roving, saturated with polyester resin. It is inside the laminated fiberglass matrix that osmotic blisters can begin when water seeps through the gel coat, seeking out pockets of incompletely cured resin within the fiberglass layers.

Tiny amounts of water get inside the fiberglass and begin to dissolve the chemicals found there. This solution then attracts additional water through the gel coat barrier by the process of osmosis. As more water enters, the pressure increases and eventually, a blister is formed. Under the right conditions this blister might expand and begin to delaminate the local area around the blister. As more blisters occur, the situation can become a problem that might threaten the structural integrity of the hull. Cored hulls present a complex problem in that both the core material and the fiberglass/ gelcoat may be damaged in extreme cases.

As builders determined that blisters resulted from water penetrating the gel coat surface, the barrier coat (usually an epoxy, or similar material that seals out the moisture better than polyester gel coat) was born. Water barrier techniques and products have grown into maturity over the past few decades.

Applying a barrier coat today is almost as easy as rolling on bottom paint, and thousands of boat owners have completed this project, protecting their boats from osmotic blisters. There are three types of barrier coat protection: 1) preemptive barrier coating on new boats; 2) blister repair alone; 3) blister repair with a barrier coat.

New Boat Preemptive Barrier Coating

New boats are sometimes delivered with a barrier coat applied at the factory, and may even include a 5 or 10 year blister warranty. It is important to note that you may have to treat the barrier coat in a specific way to keep the warranty intact, so consult your warranty before you do a thing to the bottom of your new boat. If your boat does not have a barrier coat, you may want to investigate whether the builder has used specific resins which are resistant to osmotic blistering (commonly, vinylester resins are used in this instance– this type of resin is considerably more costly) so that you may not have to apply a barrier coat to the underwater portion of the hull.

If the vessel has no special barrier protection and your boat is in the water year round, especially in a warm-water area, or if other boats from the same manufacturer (or of your model) have a history of blister problems, barrier coating as a preventative measure makes a lot of sense. It is far easier to apply a barrier coat to an intact hull than to clean out and fix blisters first, and then roll on the epoxy. A properly applied barrier coat may also increase the resale value of your boat.

If you want to take this preemptive action, then wipe-down the bare hull with a solvent dewaxer, sand thoroughly, but lightly, and apply the recommended thickness of barrier coat (usually 2 or 3 coats), followed by antifouling paint appropriate to the area’s waters.

Hamilton Marine offers barrier coat products from a number of paint manufacturers. A review of their manuals will reinforce how seriously they take this problem. They give drying times along with precise recommendations as to the number of coats that will give the optimal film thickness, after it dries. Follow these instructions closely and you will have satisfactory results.

Blister Repair

Many times when a boat is hauled you’ll see isolated blisters on the hull, or possibly on the rudder, but in general the gel coat looks smooth and there is little evidence of major damage. In these cases, it may only be necessary to fix the blisters and put off the much more costly barrier coat application for a few more years—with luck, forever!

As soon as the boat is hauled, scuff-sand lightly over the blisters before they ooze all of the liquid out, deflate, and become hard to identify. Mark the blisters, so you don’t miss any later. Open the blisters by scraping or grinding away the damaged material until there is no sign of delamination. Flush with water and allow the damaged areas to dry, which could require from several days to a few weeks. Circulating warm air will speed the drying process.

When the cleaned out areas are dry, the first step is to seal the laminate with low viscosity 100% solids epoxy resin. This coat penetrates the surface and prepares it for the epoxy filler, which is spread in place to fill the void. Deep pockets, or large areas, may require a few coats of epoxy filler compound, although the material will cure even if it is applied in a thick layer. When the void is filled, sand the surface to match the surrounding hull contours. A final coat of regular density epoxy (do not use 5-minute epoxy, as this is not waterproof) will seal the filler. Sand after curing and you’re then ready for bottom paint.

Blister Repair with a Barrier Coat

Older boats must be very dry before you attempt to repair them. By dry, we mean that the hull laminate must have the water evaporated from it, either through natural drying (very slow), by artificially warming the hull (expensive), or by using a vacuum to draw out the moisture (technically complex and expensive). Any moisture that is resident in the hull laminate will be trapped by the barrier coat, if it is applied prematurely. Avoid doing this—or all your efforts will be in vain. Sever problems might require stripping the gel coat entirely, testing the laminate with a moisture meter and letting the boat sit on the hard for as many months as it takes for the meter to read the same– both above and below the waterline. Six months or more is not unheard of.

The coating procedure is a combination of the first two procedures above: coat the areas of the hull where the gelcoat was removed with unthickened epoxy, fill the holes with epoxy filler and fair, and then apply 4–6 coats of the barrier coat material to the outside of the hull. Putting on all of these coats can be greatly speeded up by coating “wet on wet”. This means that you wait until the layer you are overcoating has reached a partial cure, but is still a little “tacky”. If you roll on another coat at this point, the two layers will chemically bond, and you won’t have to sand between coats, or wait for each coat to cure completely. This may allow three or more coats per
day under ideal conditions, and it produces a better bond between coats of barrier coat epoxy.

More Help

Hamilton Marine recommends and sells a number of good books on hull repair: Don Casey’s Sailboat Hull and Deck Repair and This Old Boat are both good resources. We also recommend two introductory publications from Gougeon Brothers’ series of WEST SYSTEMS books: Fiberglass Boat Repair and Maintenance and Gelcoat Blisters: Diagnosis, Repair, and Prevention. They are inexpensive and full of information. For free information on the topic you also may want to check online at www.yachtpaint.com, or www.pettitpaint.com. You’ll also find up-to-date information based on current experience can be found in many boating magazines and on other web sites. Analyzing and following procedures outlined in these publications and web sites should help you find a solution to your boat’s particular blister problem.

Antifouling Paint

Boat owners quickly discover that the combination of boat bottoms and water almost always yields a very healthy biology experiment…bottom growth! Although we are not aware of a perfect preventative, modern anti-fouling paints are quite effective and considerably healthier for the environment than their predecessors.

As is typical in our times, the available selection can be confusing. We don’t profess to have the “magic bullet” for preventing bottom growth…however; we can explain the basic choices.

SOFT BOTTOM PAINT

The time-tested, affordable, copper based antifouling paint commonly know as “soft” bottom paint has been all but replaced by modern technology. It is moderately effective, especially in cooler waters where growth potential is less than in warmer climates, as it slowly washes off the bottom of your boat. Depending on how heavy an application is applied and how long your boat is in the water, it may be mostly gone by the time you haul the boat out at the end of the season. Pressure washing the hull all but guarantees a very minimal build-up of paint. If you are on a tight budget, soft antifouling paints may be the way to go. There are two notable downsides to soft antifouling coatings- they are becoming more difficult to locate, and once you commit to using a soft paint you must stick with a soft antifouling paint…or remove all the paint completely before applying a different type of paint. This probably accounts for the lack of popularity, and hence, the difficulty in finding this type of paint.

HARD BOTTOM PAINT

Hard antifouling coatings are probably the most commonly used. They tend to have more biocide (generally, cuprous oxide) in them and are more effective because of that. They tend to go up in cost based on a higher percentage of copper in the paint. As hard paints have a tough surface, which can be burnished in many instances, they make good finishes for the bottoms of racing boats (especially sailboats, where every 1/10th of a knot increase in speed counts!)

This hard surface comes with a cost however—paint build-up over multiple seasons. When you notice areas of paint flaking off the bottom of a boat when it’s in storage during the off-season, you can bet that you are looking at multiple layers of a hard antifouling paint. This flaking is the result of layers of paint build-up and separation of the base coat from the hull. When the flaking gets to be too severe, one must resort to the Draconian practice of removing the existing layers of paint down to the hull surface…either by stripping/scraping or by grinding/sanding. In any event, should you find yourself in this situation…remember, the paint dust is toxic, as are most stripping compounds. Protect yourself…gloves, hat, painter’s suit, and a facemask are a must for this job.

ABLATIVE (POLISHING) ANTIFOULING PAINT

In the last 15 years, ablative antifouling paints have gained in popularity for a variety of reasons. They are designed to “dust off” (think of a bar of soap) the outer surface while still having an ample amount of biocide. This allows ablative antifouling paints to work quite well in most environments, assuming the boat is used on a regular basis and the outer layer’s particles are coming off as designed. The great advantage here is that ablative antifoulings, while generally quite hard to the touch, do not build up thick layers of paint that require removal after a period of time. Most often, a pressure washing at haul-out and a quick wipe down with a solvent prior to recoating is all that is required…no scraping or grinding.

There are single season antifoulings and multiple season antifoulings. The single season product will work well for “a season”— loosely defined as for as long as the boat stays in the water, is used regularly, and the antifouling coating lasts (generally, 12 to 18 months, depending on the thickness of the coating.)

Multiple season ablatives work for well over two years and don’t require the boat to be in the water continuously— that is, you can haul-out at the end of a season, re-launch the following season, etc.— until the paint is wearing away.

A common recommendation is that a base layer of a contrasting color of the same ablative paint be used beneath the final coating. In this way it is easy to see when recoating is required while still maintaining antifouling protection.

SPECIAL PURPOSE ANTIFOULING PRODUCTS

Waxes are an alternative to conventional antifouling paints. These are most frequently used on fiberglass boats moored for short periods of time, or kept on trailers, racks, or lifts.

METAL HULLS

When there is a metal based biocide in an antifouling paint, there is always the possibility of a reaction between the metal in the paint and that of the hull. This is a complex physics problem dealing with the flow of electrons from one metal to another. If the flow is from your hull, guess what? You will soon have holes in your hull. Not good. There is nothing quite so disconcerting as realizing that your beautiful aluminum boat has become a giant sieve and can not be repaired. Simply put, either use an antifouling with no metal biocide (or at least one less noble than the hull material), or apply an insulating barrier between the metal hull (this applies to all in-the-water metals: outdrives, etc.) and the antifouling coating. There are a number of great information sources dealing with this topic. We suggest that you consult them.

ENVIRONMENTALLY FRIENDLY PRODUCTS

To think that a product designed to prevent (read “kill”) growth of living organisms on a boat bottom is environmentally friendly is an obvious conflict. We are dealing with toxins and pollutants—however, there are some that are considerably easier on our ecosystem than others. These are all quite new and the jury is out on most of them. That said, they are growing rapidly in popularity, and they seem reasonably effective. Quite frankly, they will be the wave of the future, if for no other reason than they will be mandated by state and federal environmental regulations.

Most of these products use alternative biocides less toxic than copper and tin– or a “slippery” technology, creating surfaces that growth simply can’t get a good hold on.

Water-based antifoulings, as opposed to solvent-based product with high VOC (Volatile Organic Compound) content, have also made rapid gains in popularity—partially because some of the solvent based products have been legislated as too hazardous for general public consumption, while many manufacturers have developed excellent water based products than can be produced more cost effectively. These products, for the most part, have been around long enough to be proven effective.

If there is a caution with water-based antifouling paints, it relates to wooden hulls. Be sure the hull is dry enough to allow the paint to dry properly prior to launching. If the hull is too damp, the paint may not be cured and will lift off when the vessel is launched. Most wooden hulls, if they have been out of the water for over 30 days, are dry enough to apply water-based antifouling paint

SAFETY

Take all recommended precautions listed on product labels. Be aware of the hazards of fumes, dust or product contact with skin and eyes, and flammability. Many antifouling products and their support products can be very toxic.

COMMON SENSE

Conventional wisdom dictates that one gets what one paints over—so, surface preparation is important. Be sure that you can apply that hot new antifouling paint that you want over the existing paint.

You may want to use a conversion coat over “soft” bottom paint, rather than remove it. If you need to remove the existing paint, do so carefully, being sure not to damage the hull surface. If you have a fiberglass hull, when you are down to the hull surface, consider applying an epoxy based barrier coating on the hull. This will prevent further water migration into the fiberglass. If you have osmotic blistering, now is the time to address that situation. Consult product literature, as this process is well beyond the scope of this advisor.

Be sure the hull surface to be painted is roughed-up and cleaned with a solvent wash, so the paint will adhere properly to the hull surface.

Metal hulls, especially aluminum, should have an insulating barrier coat applied to the bottom prior to application of antifouling paint.

Read the product labels. All antifouling products are not created equal. Manufacturers will stress using specific procedures or their own proprietary products. While shortcuts may be possible as well as non-proprietary products (such a thinners), cheap insurance usually includes following the manufacturer’s recommendations to the letter when prepping a bottom and applying antifouling products. Fixing a failed “bottom job” tends to make one consider giving up boating.

Naturally, always feel free to consult with us here at Hamilton Marine for professional advice regarding antifouling products—or anything else regarding your boat. We will do our best to give you all the information you’ll need to do the job right…the first time.