Stained Mahogany door needs refinishing advice

[Don Morris]

My southwest facing stained Mahogany door had a shop applied "spar" poly finish applied 15 years ago. Now it shows spotty areas of a whiteish film. What's my best approach to bringing it back to the original luster or something close to that? Thanks for any and all ideas!

[Steve Schoene]

Usually, when varnish lifts it makes yellow spots. The only solution to that is to strip and re-finish. While spots may just be the varnish surface failing. You may be able to sand, with 320 grit paper, the dull spots away so that you can apply fresh varnish without stripping the old. But it really must be in good shape after sanding the surface. New varnish won't "glue down" varnish that is starting to lift from the wood.

If it lasted 15 years, it was likely a spar varnish but not a spar varnish with polyurethane, which I'd bet would have failed much sooner. Given what appears to be a relatively benign location, the door might be recoated with a tradtional marine spar varnish, whether over aa stripped door or over the sanded old finish. Epifanes Clear Gloss, Interlux Schooner, or Pettit Captain'sare the ones you should consider.