Here’s a post from Dean!
“People often ask what finish they should apply to exterior wood so that it will maintain its beautiful natural glow indefinitely. We have found that the only way to achieve this effect is proper care and maintenance.
Natural resin spar varnish, the same finish traditionally used on the bright work on boats, is the best finish to use. Initially, a minimum of 10-12 coats must be applied. After 3-4 coats have built up, the finish must be flat sanded in between succeeding coats until all grain and pinholes are filled with finish. Now your piece looks beautiful! Job well done! Finished! …Not quite.
All exterior wood must be properly maintained and cared for. If in a salt water environment, the piece must be rinsed weekly to ensure that the magnifying properties of salt and sun (U.V. rays) won’t expedite the fading of the wood color.
While rinsing, look for any chips, scratches, or other damage to the finish. If damage is found, that area must be “touched up”, that is, sanded and sealed with several coats of spar varnish. Water must not reach the wood itself or graying will begin to occur.
The bright work on boats should be sanded with 220-320 grit sandpaper then spar varnished at least twice a year for proper water and U.V. protection. Most exterior doors and gates can be sanded and recoated a minimum of once a year.
This to most seems to be an excessive schedule of maintenance. Even though it requires such extensive yearly maintenance, we have determined that spar varnish is the best finish available. Because of its elasticity it handles the constant movement of wood well and has been found to protect wood’s natural beauty best, both in our experience and by all of the boat finish experts that we have talked to. Any harder finish, such as epoxy, does not move with the wood, ends up cracking, and has to be completely removed (a very costly and tedious task). An oil finish at the other extreme, although very flexible is permeable, and will gray rather quickly, even if reapplied frequently. We believe that the beauty of wood is worth the labor intensive process of spar varnishing, and is worth maintaining.”
