Since most wood boat racers seal their entire hull inside and out to waterproof it, weight build up is a huge issue. When sealing, allow the thinned expoy to soak in for 10-15 minutes. Then take an old credit card or similar stiff plastic scraper & hold it 90° to the surface & scrape off all the epoxy you can. After it has cured, do the same with a single edge razor or utility knife blade. Scrape it down smooth. Repeat the entire process one more time. Leaves you with a well sealed, smooth surface that needs VERY little sanding for final finish with minimal weight gain. My personal preference is an epoxy that calls for a thinning agent that flashes off comparatively slowly. I believe this allows the epoxy to stay thinner longer letting it penetrate into the wood deeper.