# Polyurethane question...



## Spikezone (Feb 2, 2006)

I just went to have a visit with my friend that is going to clear my guitar for me. I was talking to him about the process and he had a concern, so I am passing it on here for some advice. The sanding sealer I can get is alkyd and he is clearing it with automotive catalyzed polyeurethane. He is worried that the poly might react with the sealer and lift it. Does anybody here think this is a viable concern? Thanx, 
-Mikey


----------



## ajcoholic (Feb 5, 2006)

Those material I am not familiar with...

IF IN DOUBT TRY IT ON A TEST PIECE FIRST!

There is nothing more brutal than putting on your last coat of clear and having the whole job spoiled by the finish wrinkling, or worse.

AJC


----------



## Lowtones (Mar 21, 2006)

Spikezone said:


> I just went to have a visit with my friend that is going to clear my guitar for me. I was talking to him about the process and he had a concern, so I am passing it on here for some advice. The sanding sealer I can get is alkyd and he is clearing it with automotive catalyzed polyeurethane. He is worried that the poly might react with the sealer and lift it. Does anybody here think this is a viable concern? Thanx,
> -Mikey


Check with the manufacturer of the sanding sealer. It will usually say on the can ( and many do ) not for use with urathane top coats. This would include polyurathane. In most cases the problem is not a reaction with the finish but rather that the urathane product will not adhere to the sanding sealer. If you've already sealed the guitar you can always give it a coat of lacquer , sand it and then give it the poly clearcoat. Or just do it in lacquer. Try to find one with a catalyst. I'd check with a furniture restorer. The cure time for nitro is quite a while ( I leave it a minimum of three weeks) before you can wet sand and buff.


----------

