These are a pair of paneled unpainted garage doors that I can’t get a nice finish to stick. Brutal sun shrinks and cracks and peels the Minwax Helmsman Spar Urethane. The wood had been stripped and sanded before application and was peeling back within two seasons. I’m ready to paint the buggers! Any ideas?
I would try a couple coats of semi-transparent stain-sealer WITHOUT a topcoat of poly or varnish. YES, this means every couple of years you'll have to wash/brighten garage doors lightly, and then reapply stain. BUT no sanding and stripping every time.
Choose a lighter color because you can put on additional coats and wood will darken over time (which you can brighten and condition with a wash: Behr #63 biodegradable or a Sherwin Williams product)