Renewing a Poly Exterior Door Finish

Short of stripping to bare wood, is there a way to freshen up a polyurethane finish on a door? April 17, 2009

I have two exterior doors that get east/west exposure. They have been installed about five years and are starting to show their age and the client would like to bring them back to life (without replacing or stripping and re-staining). The original finish was a dark stain on douglas fir doors finished with a couple of coats of satin poly.

Any recommendations on new finish that may hold up a bit better and/or tips on approaching this project will be greatly appreciated. The client readily accepts that the refinish (not being completely stripped) will probably not be as good as the original.

Forum Responses
(Finishing Forum)
From contributor B:
If you want it to look right, strip and refinish. What you have here is polyurethane that has begun to oxidize and loose its flexibility, thus the peeling you are most likely seeing. Sanding it down and throwing on another coat may brighten it up but it will not look like a new door finished and it will probably fail since the coating underneath is much, much older and much less flexible.

From the original questioner:
Thanks for the input. Actually, there is absolutely no peeling on either of these doors. The biggest, and as far as I can tell, issue is simply the oxidation. I will agree with you about the best solution being a strip and refinish, as does my client. However, this is a rental property at present.

From contributor L:
It sounds like if it is strictly oxidation with no peeling, just a good overall sanding to get down to fresh coating and a recoat should suffice. It is not going to look new, but it should look much better. You might find that you can't get to a decent looking layer of finish if it is oxidized all the way through. If this is the case then there will only be one way to make it look good again, strip and refinish.

From contributor R:
Just clean it real good first and then sand it with some 150 or 120 grit paper and apply another coat or two of poly. Itís what the customer is looking for and he/she isnít interested in a complete re-do. Make sure you inform them of the pitfalls of doing this and that you will not be responsible when down the road the finish starts flaking off.

From the original questioner:
That's what I'm looking for input on - what are the pitfalls? What do I need to warn my client about? Why is the finish going to flake off? Care to expound on any of these comments?

From contributor L:
Polyurethane doesn't like to bond to itself. It will be bonded by the roughness of the surface, no chemical bond and poly will not melt into itself. This is the pitfall. Most likely, if you do a good job cleaning and scuffing there should be no issues. But it can happen. Just put a small disclaimer in your contract and have the client initial it so they know what they are getting into.

From contributor R:
Just explain to the owner of the door that they are asking you to wax a dirty car, without asking you to wash it off first. The finish that is on there now is a number of years old and its most likely dried out and the color is fading. For me itís kind of a no-brainer but for a customer whoís trying to save money "just because itís a rental" itís not easy to digest.