As with anything worth doing, preparation is the key to a job well done.
Take a close look at your topcoat paint for a minute. With all the salt, sun, scrubbing and swabbing, it’s hard to believe it’s held up as long as it has. And when the finish starts to go, it’s easy to overlook because the process is so gradual. But if you really stop and inspect the surface, does it appear chalky or porous? Do you have an uneven sheen or areas that are discolored? If so, it might be time to start thinking about new topside paint. Like anything else on your yacht, staying ahead of the projects can help reduce the cost and reduce your downtime.
With all the choices out there, choosing the right paint and process can prove to be a daunting task. That’s why we’ve put together a series of articles on what to consider before deciding on a new topcoat application. With help from experts at major paint manufacturers, we’ll help you get to the key things you need to consider. This month, we’ll examine some ways you can recognize paint deterioration and how you can get a head start on prep work, whether you do the work yourself or if you ultimately decide to have a qualified yard do the actual painting.
Tripp Nelson, Alexseal Yacht Coatings:
One of the biggest mistakes I see is that people start sanding their old topcoat right away.
As you’re repainting the boat, you’re applying products to that boat that you will never take off, at least not for many years in the future. You have to have good surface preparation so that when you apply the coatings to the boat, when it’s time to repaint again, the surface will still have good adhesion. In order to get that, it’s really important that you clean the surface very well before starting the sanding process. That helps remove any contaminants that would otherwise get pushed down into the valleys of the sand-scratch pattern. So you want to clean the surface while all the boat is still watertight and all the portholes are in place and all the fittings are still caulked.
Jack Hickey, Blue Water Marine Paint:
Assuming the topcoat finish and the related primers are single-package products; this can be done as a do-it-yourself project.
The paints needed, primers and finishes can be applied, but it is wise to test your application skills on a substrate other than your boat beforehand to see if the finished look is acceptable.
Before attempting to start a project like this, talk to the store about the brushes you will need to maximize the appearance, what reducer to use and how much reducer you need to add to the topcoat finish for a successful application. Also, ask what thinners are acceptable for clean up of the painting tools after application of the topcoat finishes and primers used.
Unless you have experience with spray-paint applications and the amount of labor involved in tenting your boat and the air flow required, you should consider sticking with single-package systems and leave the professionals with spray painting. For any DIY application, read the painting manuals available from the marine paint suppliers and read them carefully.
For many applications of topcoat finishes and systems, there are many filling, fairing and surfacing compounds available. Make sure the one you choose to work with is compatible with the system you plan to apply.
Jim Seidel, Interlux Yacht Finishes:
With the right preparation and a good amount of patience a do-it-yourselfer can paint the topsides (bare gelcoat as long as it’s not cracked) and get a really good finish.
This is a simplified explanation and assumes you’ll need two coats of primer and two to three coats of finish.
Make sure to read the instructions carefully! The first step is to clean the surface really well. Then, hose the surface off and watch the water. If it sheets off then the surface is clean. If it beads up and separates, you need to clean again. After cleaning, using a dual-action sander with 80-grit sandpaper, remove the sanding residue by wiping with fiberglass solvent wash using the two-rag method – wipe on with a wet rag and wipe off with a dry rag – and change rags frequently. Once the surface is ready, apply the tape. Use a good quality masking tape that can be left on for several days. Use a plastic squeegee to press down the edges so the paint does not creep under the tape.
Topside paint will adhere to clean, sanded gelcoat, so primer is not needed for adhesion. You are applying the primer/undercoat to improve the finished surface, take care of minor surface defects, fill any porosity and get a smooth ‘canvas’ on which to apply the finish. Once the area has been taped, apply a coat of primer/ undercoat and allow it to dry. As you are re-sanding, inspect the surface for defects and apply a fill compound to any areas that are dinged, nicked, dented or not exactly smooth and fair. To avoid flat spots when applying and sanding fillers on curved surfaces, use spreaders and sanding boards that are twice the width of the area being filled. No matter how smooth a finish you have achieved, when filling or fairing, all fillers must be sanded before overcoating to ensure good adhesion.
Coming next month: We’ll look at the different types of topcoat finishes (single-pack, two-part polyurethane) and explore the various applications for each product.