Painting a wooden boat on your own can be a daunting task. The amount of information about the correct way to paint a boat is staggering! First time boat owners may be at a loss when trying to make a plan for their first project. The Bottom Paint Store’s aim is to make this process as stress-free as possible so you can enjoy working on your boat and ultimately, enjoy the fruits of your labor!
If you have a boat that sits in the water for long periods of time, but don’t have a problem with fouling in your area, you will need a durable topside boat paint that can be submerged. (Fouling refers to the buildup of slime, algae, barnacles, and other organisms that adhere to the hull of a boat.) To determine what paint is best for your boat, ask yourself these questions:
1. Will my wooden-hulled boat be submerged long-term?
Constant submersion will require a more durable, 2 part coating. The protection that a 2 part coating can provide is superior to almost all single stage paints. Primer is also very important. It provides a surface for the paint to bond with and it also protects the wood from water seepage.
Recommended Primer: Etching Primer 664D Preparing Raw Wood (Unpainted): Bare wood should be sanded smooth with 80 grit paper before the application of SM-664D Etching Primer. Select this primer to fill the grain of the wood and create a smooth easy to adhere to surface for the paint. It has an unusually high amount of solid material, sands beautifully and locks our air and moisture. Recommend allowing primer to dry for 2-4 hours before sanding with 120 grit paper. Often repeated coats are applied to achieve a smooth finished surface. Repeated primer coats and sanding may be continued until the grain has been filled and the surface is completely smooth. Recommend 180 grit sandpaper for use in finish sanding. Fasteners in wood hulls are always countersunk below the surface of the planks. It is necessary to fill these countersinks in order to achieve a completely smooth finish. Surfacing putties are preferred over epoxy or polyester putties because epoxy putties can be harder to remove should it ever become necessary to remove a plank for repair. Carvel planked boats require a seam compound. Traditional seam compounds are never applied until after the hull has received a primer base coat. Traditional seam compounds should never be applied to bare wood, however, polysulfide seam compounds must be applied only to bare wood. Apply polysulfide seam compounds into the seam prior to applying primer.
Recommended Paint: Supreme Urethane (SM-266) The most durable, “rough and tough” coating. This can be brushed, sprayed, or rolled. Unless you are experienced with spray equipment the best way for the “do-it-yourself-er” to apply it is the “roll and tip” method. Traditionally, one person rolls a thin coat of paint onto the prepared surface while a second person follows the roller with a brush. Using just the tip of the brush, smooth out the coating in long sweeping strokes. Tipping removes bubbles created by the roller. This product sets up quickly so speedy application and proper thinning will help prevent brush or roller drag. Spraying offers the best film thickness control, however, rolling is often the best way to achieve the recommended maximum Wet Film Thickness which is 4 mils. The recommended DFT (Dry Film Thickness) is 4 mils minimum. Applications applied too thickly may not adhere or level properly, run, sag take longer to cure or result in unwanted amber resin color. Always adhere to the manufacturers recommended WFT and DFT (Dry Film Thickness) for best results. Theoretical coverage is 300 sq.ft/GL. Ironside has a mixing ratio of 7:1 with a 10 minute induction time. Be very careful to mix the paint correctly to avoid problems with curing. Apply 2 or 3 coats to the hull. For best results, recoat within 4 hours or after 24 hours. Sand between coats after 48 hours have elapsed. Recommended minimum cure time is 5 days under most conditions.
2. Will my wooden-hulled boat be hauled out after use?
If the boat will be hauled out after use then a 2 part coating is not absolutely necessary. A less expensive coating can be used and the wooden hull will still have protection.
Recommended Primer: Supermarine Etching Primer (SM-664) This primer creates a virtually unbreakable chemical bond to whatever it has been applied to which allows it to be used almost anywhere and most any application! Sand the Bare Wood Hull smooth with 80 grit sandpaper. For the 1st coat of primer, thin the primer down 10-15% with SM-605 Synthetic Thinner and apply to the bare wood. Etching Primer will fill the grain of the wood and create a smooth easy to adhere to surface for the paint. It has an unusually high amount of solid material, sands beautifully and locks our air and moisture. Apply the 2nd coat of primer without thinning. Dries to the touch in 30 minutes, tack free in 1 hour, recoatable in 2 hours, dries hard in 4 hours. Recommend waiting until 4 hours have passed before recoating with primer or paint. Coverage is approximately 250 sq.ft/GL, depending on the texture and porosity of the surface. Apply by brush, roller or spray. Next, Apply your choice of 1 part Epoxy topcoat.
Recommended Paint: Mono-Epoxy Paint Single stage epoxy formula – less hassle than a 2 part epoxy. Mono-Epoxy is highly water-resistant, resistant to chalking, fading & chipping, resists peeling & cracking, weather-resistant, submersible long term. Recommended DFT: 5 mils. Coverage is approximately 250-300 sq. ft. per gallon @ 3 mils wet. For best results recoat within 24-48 hours or sand between applications. Allow top coat film to cure thoroughly before allowing it to enter full service duty. The recommended minimum cure time is 5-7 days under most conditions. DO NOT allow newly applied paint to get wet for a minimum of 48 hours. The dry cured film may be wet sanded and buffed to remove runs and blemishes. See the Mono-Epoxy product data page for more application tips.
Note: Both Supreme Urethane (SM-266) and Mono Epoxy are compatible with Etching Primer (SM-664). If your boat will not be in the water constantly and you would still like top of the line performance, you can apply a 2 part primer and a 2 part Epoxy Topcoat. There are no hard and fast rules for painting your own boat. That being said, you could also apply a single stage primer like SM-664 and go with a durable 2 part topcoat. Just be sure to follow all manufacturer recommendations for priming, mixing, and thinning to avoid problems with curing.
3. Does the wood hull have a coating on it now?
If the wood hull has a coating on it currently, the suggestions for Question 2 should be followed. There will a few different steps in the prep stage of the project, but everything else will be the same.
Prep: Sand the existing coating with 80-120 grit sandpaper. Wipe down with a clean tack rag. All surfaces must be thoroughly clean and dry before the application of any primer. You don’t have to totally remove all the previous coating. Just try to get rid of all loose paint and be sure that the surface is sound.
Recommended Primer: Etching Primer (SM-664) When applying primer, do not thin it down like you would for bare wood surfaces unless you are spray applying. Some thinner may be used to run the primer through the spray gun. Apply a minimum of 2 coats of primer. Etching Primer should be allowed to dry a minimum of two to three hours before recoating with subsequent primers or marine finish coatings. It should be applied to a dry film thickness between 0.3-0.5 mil.
Recommended Paint: Mono-Epoxy or similar coating listed here. Follow all manufacturer guidelines for each product.
Other Paint Products for Single Day Use
Here are some other products that are not recommended for long-term submersion but can be applied to wood-hulled boats. These products are much less expensive, but are also not as durable and long-lasting as the products mentioned above.
Duralux Yacht Primer and Duralux Topside Marine Enamel
Pettit EZ Prime and Pettit Easypoxy
Interlux Pre-Kote and Interlux Brightside Polyurethane
For other Helpful “How To” Articles about Topside Boat Paint, Click one of the links below.