On Refinishing Veneered Wood
When I was a kid, I spent a lot of summer weekends working with my father on his sailboat, including refinishing the wooden mast and boom several times. He and I learned a lot about bright-finishing wood and how urethanes and varnishes react to exposure to the elements.
When I was in college, I employed those lessons when I built a plywood sea kayak that I also gave a natural wood finish. 15 years later, the kayak is still in perfect condition despite its extensive exposure to sun, water and generally rough abuse. It draws favorable attention wherever I paddle it.
If I ever need to refinish the wood in a coupe, I'll follow exactly the same procedure, because the results are just as beautiful and DRAMATICALLY more durable than simply using varnish or polyurethane. Most importantly, it's actually quite easy to get a top quality result.
The difference is the use of a marine-grade clear epoxy like those produced by West Systems. After proper preparation of the bare wood, you can mix the epoxy and roll it on with a thin foam roller to get a nice even coat. The foam roller will produce very small bubbles on the surface, but if you draw a brush gently over the surface after rolling it on, you'll get a perfectly even, crystal clear coat. Give the wood 2-3 coats of epoxy on all surfaces (front, back and sides), allowing proper curing time in between and using steel wool or very fine sandpaper to prepare the surface for the next coat. Then use the same procedure to apply 2-3 coats of marine-grade varnish, thinned appropriately, for the final finish. I used Z Spar Captain's Varnish. All good marine varnishes have UV inhibitors that will prevent cracking, fading, etc.
The wood veneer on coupes generally breaks down in areas that have been exposed to excessive water, sun or abrasion (i.e. pieces of veneer chipping off at the edges). However, using a base coat of marine epoxy below the varnish will seal the wood entirely and will completely prevent the veneer from peeling away. Trust me, the epoxy is much, much harder than the wood itself. Water will never be able to seep into the wood, and any cracks that may eventually appear in the varnish or urethane won't reach the wood either, keeping it beautiful for a VERY long time to come.
Ian