When we bought our 41 DCMY it was a mess. A good friend that is a master with brightwork taught us how to strip and refinish without dimensionally changing or removing any wood. The key is to NOT sand off the old finish. Below is the procedure. It is allot of work, messy and requires 12 to 15 coats of varnish, but the results are spectacular and long lasting.
If you are a tree hugger - don't read any further.
1. Use a strong (non-green) paint and varnish stripper. Back in the day we used Petit marine paint and varnish stripper. Brush on the stripper, let it rest until the finish bubbles. Then scrap with a plastic putty knife. You may have to repeat this step several times until all old finish is removed from the surface.
2. Apply another coat of stripper. Using a short bristle brass brush - about 1.5 inches X 1.5 inches (like used to be used for cleaning white wall tires) brush the old finish from the wood grain. This may take a couple of applications working in about 1 foot square areas. A smaller brass brush (toothbrush size) may be needed around trim, etc. Tap the brush on a piece of newspaper to remove the debris collected.
3. Lightly sand the stripped and dried surface with a DA sander with 220 grit paper. Hand sand trim and curved surfaces.
4. Vacuum the surface of the wood using an upholstery brush. Clean, clean and clean again the entire area.
5. Wipe the surface with a lint free rag and a generous amount of automotive painter's Dupont Prep-Solve or equivalent. Mineral spirits will work, but takes longer to dry. The look you see while the wood is wet immediately after wiping is the finished look you will get. If there are splotches, go back with the stripper and fix them now.
6. Wipe the area to be finished with a tack-rag (a wax impregnated cheesecloth available at paint stores). Don't rub hard and transfer wax, just wipe lightly to remove dust.
7. If you wish to apply a stain, now is the time to do it. After staining and drying the surface, repeat steps 5 and 6.
Important Varnishing Tips: The most important thing is avoiding contamination of the finish with dust and dried varnish debris.
THE BRUSH
Use a high quality Badger hair brush.
DO NOT clean your brush between coats. Drill a hole through the handle and suspend the brush on a nail or wire in a tomato can of lacquer thinner. Don't let the brush touch the bottom of the can. Keep adding lacquer thinner as it evaporates. Every few days you may need to dump and refill the can with fresh lacquer thinner.
Sling the lacquer thinner out of the brush just before applying the next coat. A couple sheets of newspaper make a good target for collecting the slung out lacquer thinner.
VARNISHING TECHNIQUE
Open a fresh can of varnish. Using a clean straight bladed screw driver (and holding the can securely) punch two or three holes with the screw driver through the bottom of the can's sealing groove. This will allow varnish to drip back into the can rather remain trapped in the groove. It will not effect the lid's seal but will prevent a large build up of dried and semi dried varnish.
NEVER DIP THE BRUSH in the varnish can. Use a plastic or paper dish, cup or bowl into which you have poured the varnish from the can. Reseal the varnish can immediately and pour only the amount of varnish you can use in a 15 to 20 minute period.
When pouring varnish from the can into your brushing container cover the top of the varnish can with a piece of pantyhose. This will filter out any debris that may have entered or generated in the can.
When preparing to pour from a partially full varnish can a skin may have formed on the surface of the remaining varnish. Do not attempt to remove this skin. Just puncture/tear it with a screwdriver and let the varnish run through the tear while pouring through the pantyhose.
NEVER POUR UNUSED VARNISH back into the can. When finished with one coat, invert your brushing container over a can or bowl to allow any remaining varnish to drain/drip out. Leave your brushing container inverted to drain and dry until the next use. This way it won't collect dust. You can use the same container for a long time.
NEVER SHAKE OR STIR VARNISH. Varnish does not settle in the can. Agitation only introduces air bubbles that will cause problems.
Lay the varnish on and brush out, but do not overwork or apply so much varnish that runs form. Try to brush from the "dry" towards the "wet" area before lifting the brush. Try to avoid starting the brush at a surface edge. This will result in drips running down the edge. Plan your work to always maintain a "wet" line as you progress.
8. Using your Badger hair brush, apply the first coat of varnish. On the interior I have had great success with Interlux No. 100 Speed Varnish for the first 9 or 10 coats. It dries fast enough to let you get several coats a day on. Some say that thinning the first coat aids adhesion. I have never thinned the first coat, nor ever had any problem with adhesion to properly prepared wood. If you are varnishing outside brightwork, use a UV inhibited varnish from first coat to last.
9. Between coats sand lightly by hand with 220 grit paper just to remove any trash and dust. If any severe runs are evident sand them down, but don't try to remove them completely if it means breaking through the surrounding finish or stain to bare wood. After sanding repeat steps 4, 5 and 6.
10. After about 9 coats sand large flat areas with a DA sander and 120 grit paper. DO NOT break through the stain to bare wood. Sand trim and curved areas by hand with 120 grip paper. At this point the "grain" texture should be mostly gone. Don't worry that you may seem to have sanded off most of the varnish you just applied. The objective is to fill the grain without breaking through the stain.
11. Repeat steps 4, 5, and 6. Then apply the next several coats using a quality marine spar varnish compatible with Interlux No. 100 if that is what you used for the filler coats. If you used a UV inhibited varnish from the beginning, continue with that. For interior work I have had good success with Interlux "Original" No. 90 spar varnish for the finish coats. You will need to wait 24 to 48 hours between coats before sanding the finish coats since these varnishes take mush longer to dry.
12. Apply another several coats of finish varnish, sanding between coats with 320 grit and cleaning between coats, until a smooth grain free surface is obtained. It is sometimes necessary to do another DA sanding with 320 grit to remove remaining grain texture after a few more coats.
13. THE FINAL COAT (YOU HOPE)
Repeat steps 4, 5 and 6. If you are satisfied with the "wet" look, do all you can think of to clean the area and prevent dust (including turning off the AC, closing the windows, stripping your clothes off, etc.). Making no sudden movements - Repeat step 6. Then apply the final coat working to maintain a "wet" line as you progress across the area to be coated. Since it may be hotter than normal due to your dust control efforts, be mindful of dripping sweat into your brushing container and onto the surface being varnished. It is helpful to have allot of bright lighting. Occasionally stop and look at the finished surface on the "wet" side of the line from a variety of angles to be sure you have not left any "dry" spots that you did not see. If you see a dry spot or trash in the finish beyond the "wet" line, resist the temptation to do anything about it. You will only make it worse.
My wife and I refinished the mahogany interior of our '65 Hat using this technique 26 years ago. It is much brighter and durable than the original factory finish. We used something like 13 gallons of Petit stripper and 7 cases of Interlux No. 100. Every 10 years or so we lightly hand sand and apply a new top coat to brighten the finish.
