Minwax Helmsman Spar Urethane exterior door refinish

[David Oborne]

Hello,
Does anyone know if this type of finish has to be completely stripped off?
It is on wooden exterior doors that are at least 5 years old, but there are some spots that are overall dull.
Is this something that I can just lightly sand out and put another coat on or remove it completely?

Thank you for your information,
Dave

[Todd Bender]

I have it on my front doors, and just sand and recoat when needed.

[Steve Schoene]

You can sand and refinish, but it can only ve done a few times, before the thickness becomes an issue that can cause the finish to crack or lift from the surface. In that case you need to remove entirely and start over. If(when) you reach that point I strongly recommend using a better spar varnish. Tests have shown the Minwax stuff to be the least capable of the lot. Good marine varnishes such as Epifanes, Gloss, Pettits Captain's, or Interlux Schooner will generally outlive the Minwax by several multiples of time.

[Doug Hepler]

David,

It's hard to predict. Old, fully-cured polyurethane varnish is notorious for being a poor substrate for additional coats. Even so, I'd probably sand it all well to clean off any foreign matter and give the surface some "tooth", and then apply a few coats of good marine spar varnish as mentioned above.

Doug