by Pmullen503 » Fri Sep 01, 2023 9:53 am
Any plywood, especially cheap luan, will eventually deteriorate with just Poly or paint. The wood is constantly expanding and contracting with changes in humidity and temperature. Any finish alone will not stop this process.
Short of sanding down to the bare wood and covering it with epoxy and glass cloth, and then maintaining a UV resistant poly or varnish finish, the key will be to limit the temperature and humidity swings. So park it in the shade or garage it. If you tarp it, make sure that air can circulate around it so humidity doesn't build up. Plan on sanding and recoating with Poly every year or three and inspect carefully for any sign of damage, especially under the aluminum trim at the bottom of the sides.
Mostly, enjoy your TD. You'll have to invest some time and care in maintenance but if you are vigilant, it should last a long time.