Official Luthiers Forum!

Several months ago I read a couple of very good articles on using polyester finish.
Having just purchased a bunch of nitro, I decided to spend some time & money on a dedicated gun & a better spray booth & change over to polyester when the nitro was used up.
Well... The time has almost come, & now I read that some folks are having some pretty serious problems with the polyester finishes. (I believe Mario recently wrote about adhesion problems he's been having)
Has anyone got a handle on what is causing the problems?
Are there specific woods that are problematic? Sealer / primer issues? How about catalyst quantity relative to temperature &/or humidity?
I'd really like to switch to a process where pore filling & leveling is less of a chore, but I'm a bit reticent to give it a try if the finish is likely to peel off.
I went through that with the early polyurethane aircraft finishes & don't feel the need revisit that disappointment.
Any advice will be greatly appreciated.
Thanks in advance, Daniel

I've only read positive things about polyester, mostly from Mario. All I've seen him state is that you really, really need to make sure you've sealed rosewoods off with a dedicated sealer (sold by the finish mnf) before spraying a finish. Other than that, it sounds like an almost ideal finish: hard, clear, cures very fast. It also sounds like a pretty 'picky' finish, especially compared to Nitro, which is a pretty forgiving finish, overall.

Thanks for your reply Mattia;
That was my impression too. After reading Mario's first set of posts on MIMF, I was convinced that it was worth the investment in setup & tooling.
I was hoping Mario would jump in & give us an update... See if he has the bugs worked out.
Guess I'll order some polyester & do some test sprays.
Cheers,   Daniel

Been busy....

Yes, I have the bugs worked out. BEst advice I can give is RTFM. And don't try to out-smart the guys that made the stuff. When they say 'do this', do it, or else <bg>

Thanks Mario;
As soon as I can find an FM, I will R it & follow like the proverbial lamb.
I tend to get "clever" & cut corners... Usually it works out fine, but I'll resist temptation in this case.
Dan'l