Tips and tricks for achieving a quality finish
Tips and tricks for achieving a quality finish
By Bob Comstock
As a member of an antique and classic boat club and owner of a 1938 Chris-Craft Deluxe Utility, I see a lot of brightwork. Some of the best work I’ve seen is on Charles M. Royce’s collection of five classic wooden boats, among them the 35-foot 1939 Herreshoff tender Corsair. The person responsible for everything from maintaining the brightwork to running these classics is Kirk Reynolds of Westerly, R.I.
Staining and varnishing is a task many boat owners face, whether an annual touch-up, a small repair, or a complete refinishing or restoration. Reynolds’ techniques, as described here, will get you started on the right course to a quality finish.
If you’re refinishing and not just recoating, determine if there is enough wood to strip and sand. Keep in mind that sanding will remove about 1/16 to 1/8 inch of wood. Look at how deep the bungs are, and determine if they need to be replaced.
Wash down the boat if there is a lot of salt on it and let it dry; vacuum it if it’s very dusty. Remove all hardware and place in individual labeled plastic bags. This is especially helpful in keeping track of screws, and saves time when reinstalling the hardware.
Depending on the project, you may need to mask off an area. For short-term masking, use 3M blue masking tape. It can be left on only for a short while, with minimal exposure to heat and moisture, or it will leave a glue residue behind. For longer-term use, use 3M green masking tape, which has more UV and water protection. For even longer-term use, use 3M silver tape. For final coats and light masking, use pressure-sensitive blue tape.
Kirk’s tip: Before getting started, especially if it’s your first time refinishing wood, experiment on an inconspicuous place.
Removing the old finish
If you’re sanding, put on a dust mask and safety goggles, and remove the varnish down to bare wood. Depending on the magnitude of the project, you can use a heat gun to remove the finish. On hull sides, Reynolds uses a paint remover to strip varnish because of the size of the area. He likes Rock-Miracle paint remover for removing marine finishes, including varnish.
A heat gun can scorch wood, so be sure to keep it in motion. And use a heat shield, such as a 9-inch spackling blade, to protect adjacent surfaces. Hold the heat gun at a slight angle in your left hand (if you’re right-handed) and the scraper in the other.
Scrape off the varnish as it loosens, using a 1-inch hook scraper, with the blade at a 45-degree angle to the surface. The 1-inch scraper allows better control than a 3-inch one, and there is less chance of gouging the wood. Use moderate, consistent pressure until the finish is removed down to bare wood. If there are many coats of varnish to remove, you’ll need to make several scrapes to get through the entire finish.
Sun bleaching and stains in the wood also can be removed with the scraper. Be sure to remove all the varnish and stain from the wood; it will save work in the long term.
Kirk’s tip: Use a 1-inch Red Devil scraper with a hooked blade, and make a new 3- to 6-inch wooden handle so your fingers don’t get burned. Plastic scrapers don’t hold up well to the heat.
Reynolds uses 3M Gold Stick-it paper for sanding everything. The “Gold” designation represents the type of glue the abrasive is put on with. (The Gold sandpaper also lasts longer.) It is available in disks that can be trimmed with scissors to fit your sander, if necessary.
On large surfaces, start with a 6-inch disk and 80-grit paper. Do an initial sanding to get down to the workable wood surface in terms of color. Reynolds uses an AEG oscillating sander that turns 10,000 rpm. As soon as a piece of sandpaper quits, grab another one — don’t scrimp on the amount of sandpaper you use. If you’re sanding by hand, be sure to go with the grain and use a soft 3M pad for final sanding, especially on bare wood.
For the second sanding, switch to 150-grit, then 220-grit for the next sanding. If you’re staining mahogany, end with 320-grit paper to eliminate marks in the wood from the previous grits. With the AEG sander, no swirls will be left behind. If you’re varnishing teak, finishing with 220-grit is sufficient. Again, all hand-
sanding should be done with the grain.
When you’ve finished sanding, vacuum the area to remove all dust. Remember, never apply a water-dampened cloth to bare wood. You’ll have to wait until the surface dries completely before getting started, and because water raises the grain, the surface may then require additional sanding.
Kirk’s tip: For the initial staining and varnishing, don’t use a tack cloth — vacu-
um only — and apply the first coat of varnish at full strength, not thinned.
Work in a warm, dust-free area and wear rubber gloves to protect your hands from the stain. Use whatever stain is consistent with existing stains on the boat. Interlux makes both brown and red mahogany stains; Chris-Craft makes a golden-walnut stain for use on its boats.
Stir the stain or put it in a shaker, making sure all solids are dissolved. If the solids are not completely dissolved, the stain will be thinner and its color paler. Be sure to seal the can properly when not in use, or the stain will get darker as the liquid evaporates.
To thin stain, pour it into a quart container and cut it with whatever the manufacturer suggests until it’s the consistency of heavy cream. Use a plastic container, since solvents will leech into those made of paper. If you’re dealing with a small area, you can use an inexpensive 1-, 2- or 3-inch disposable chip China brush or a foam brush.
For larger areas, use a 3-inch disposable brush or clean white cotton rags to apply the stain. If using rags, work quickly to get the stain onto the wood, rubbing against the grain to work it in. Wait until the stain gets a little hazy, then do a final buffing with a clean cloth. Let the stain dry, following manufacturer’s directions, before applying varnish.
Kirk’s tip: Most manufacturers say to let the stain dry for 24 hours. That way, if you’re applying a thinned varnish, it won’t pull up the color. But when using full-strength varnish, waiting a half-hour is sufficient.
Reynolds uses Epifanes varnish, in part because it’s been used before on Royce’s boats, and blends well with the existing work.
Apply the first coat of varnish full strength using a good-quality badger brush and working with the grain of the wood. Reynolds prefers thinner badger paintbrushes, such as a Red Tree 1-1/2- to 3-inch brush, because they tend not to hold as much varnish and the bristles are more flexible. Let the varnish dry thoroughly, according to manufacturer’s directions.
Sand between coats using 320-grit sandpaper to enable the next layer of varnish to grab onto the surface. This is known as “tooth-scratching.” Never sand between coats with coarser than 220-grit paper, and be sure not to remove the shine down to the stain. If using a buildup varnish, use a tack cloth to remove dust between coats. If using a non-buildup varnish and sanding with 320-grit paper, it’s best to vacuum and use a tack cloth between coats.
Aim to achieve a flat, smooth finish, with the grain of the wood completely filled. When building up layers of varnish, “gassing off” occurs, so you may see sanding marks from varnish that hasn’t cured. It will take about six to 12 coats of Epifanes, depending on the type of wood, and at least one or two final coats over that to achieve a finish that will last the boating season. A good rule of thumb is that one coat will last one week, two coats will last two weeks, and so on.
When you’ve built up the desired layers of varnish, you’re ready to apply the final coats. If you’re using Epifanes buildup, use the standard Epifanes gloss varnish for the final coats and a Scotch-Brite pad for scratching the
surface between final coats. For a nice finish, apply a topcoat of full-strength
Epifanes and let cure for 24 hours.
Kirk’s Tip: For interior varnish work, use a rubbed-effect varnish, which has limited UV properties. Both Epifanes and Interlux make this type of varnish.
Decks and other horizontal surfaces that get wear and tear and full sun exposure need three coats of varnish annually. Remove the hardware and sand with 220-grit paper, if you’re confident that there are enough layers of varnish underneath. After the first coat of varnish sand with 400-grit paper. Apply two final coats of varnish and use a 3M Scotch-Brite pad between coats.
If the varnish is cured with time or age, Reynolds recommends using the gray 3M Ultrafine Scotch-Brite pad, which doesn’t have the tooth that sandpaper does. If you need a bit coarser pad, use the red Scotch-Brite pad. (This will not remove dust or any irregularities.)
For the hull (topsides), apply two coats of varnish, depending on the condition of the surface. You’ll need to apply additional coats if the surface isn’t in good shape. Using these steps as a guide, your varnishing projects should be more enjoyable this season. n