Official Luthiers Forum!

OK, so this guy I met on an automotive forum who sought my help with his refinishing problem. He is refinishing a goldtop that someone painted black with latex paint....

He had his gold metallic lacquer looking good, and began spraying his clear coat.
http://s588.photobucket.com/user/studem ... sort=3&o=3

It wrinkled a bit as it dried, and as he went to sand it off... this is what happened.
http://s588.photobucket.com/user/studem ... sort=3&o=2

http://s588.photobucket.com/user/studem ... sort=3&o=1

http://s588.photobucket.com/user/studem ... sort=3&o=0

The whole layer peeled right off.... He called his paint supplier for help, and they basically laughed at him. That's when he got hold of me. It's obviously a plastic finish, but I can't imagine what caused one whole layer of clear to do this.

Anyone?

_________________
"Act your age, not your shoe size" - Prince

Adhesion issue, so it's down to surface prep. Paint, like glue, needs a surface it can chemically bond to. That means the surface needs to be clean, dry, and dust free. If he used a stripper to remove the previous finish, then it could have left a messy layer on top of the wood. If the surface was contaminated with dust, oil, or remnants of prior finish then same thing.

Best bet would be to get down to bare wood chemically or mechanically, sand or scrape the whole surface clean, then blow it off with compressed air -thoroughly- to get rid of the tiniest, stickiest bits of dust.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services

I have to agree with the previous comment. Wow. Not a good day

_________________
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The Taking Of Offense Is the Life Course Of The Stupid One !
Wanna Leave a Better Planet for our Kids? How about Working on BETTER KIDS for our Planet !
Forgiveness is the ability to accept an apology that you will probably NEVER GET
The truth will set you free , But FIRST, it will probably Piss you Off !
Creativity is allowing yourself to make Mistakes, Art is knowing which ones to Keep !
The Saddest thing anyone can do , is push a Loyal Person to the point that they Dont Care Anymore
Never met a STRONG person who had an EASY past !
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I advised him to strip the whole instrument completely and make sure it's absolutely clean before starting again.
I also advised him to get finishing materials that are compatible, and to get advice from different suppliers.
I thought perhaps he had switched brands of finish, or used dissimilar finishes - but he assured me he used all acrylic lacquers.
That peeling layer sure doesn't look like any acrylic lacquer I've ever seen.
I told him I'd ask some other folks for their take... and that's ya'll.

_________________
"Act your age, not your shoe size" - Prince

is it a Gibson, or a knockoff? i wonder if a sheet of gold colored plastic or foil was laminated on, then loosened up when the guy tried to strip the black latex?

It's an Epiphone which he stripped down to bare wood (the top had knots in it).
He applied the goldtop finish himself (picture 1).
The clearcoat either absorbed part of the gold finish, or peeled part of it off.
It's really weird in my experience.

_________________
"Act your age, not your shoe size" - Prince

heh it is kinda comical looking, like a skinned beast from a hunting excursion. some kind of catastrophic chemical incompatibility is all i can say, which i realize is unhelpful. whatever he did- don't do it

There is a whole world of difference between painting cars and finishing wood when it comes to surface prep. It sure don't look like this was striped to bare wood. Looks like he stripped the back and sides to wood and tried to shoot lacquer right over the poly finish That was originally there without so much as a kiss from a piece of sandpaper....no wonder it peeled.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

Oh, boy... I've been talking to the guy again this morning, and..... he's not as smart as he thinks he is. He told me he was using acrylic lacquer. I had him read me the cans, and it turns out he was using water based lacquer. He thought water-based meant acrylic. No wonder his paint supply guys laughed at him when he asked for help. Now he's sure they did it to him to be mean.... I may be wasting my time with the guy. I'll let you know.

_________________
"Act your age, not your shoe size" - Prince

Ummmmmmmmm I hope he is better at automotive !!!

_________________
The Shallower the depth of the stream , The Louder the Babble !
The Taking Of Offense Is the Life Course Of The Stupid One !
Wanna Leave a Better Planet for our Kids? How about Working on BETTER KIDS for our Planet !
Forgiveness is the ability to accept an apology that you will probably NEVER GET
The truth will set you free , But FIRST, it will probably Piss you Off !
Creativity is allowing yourself to make Mistakes, Art is knowing which ones to Keep !
The Saddest thing anyone can do , is push a Loyal Person to the point that they Dont Care Anymore
Never met a STRONG person who had an EASY past !
http://wiksnwudwerks.blogspot.com/
http://www.facebook.com/groups/GatewayA ... rAssembly/

Well, he redid it - and it looks much better.
He say this is finished, despite the big holes and no pickup rings.

By the way, he can't figure out PhotoBucket, so he sends me the pix to post for him......

http://s588.photobucket.com/user/studemax7/media/nox5.jpg.html?sort=3&o=0

_________________
"Act your age, not your shoe size" - Prince

Eclectec

_________________
The Shallower the depth of the stream , The Louder the Babble !
The Taking Of Offense Is the Life Course Of The Stupid One !
Wanna Leave a Better Planet for our Kids? How about Working on BETTER KIDS for our Planet !
Forgiveness is the ability to accept an apology that you will probably NEVER GET
The truth will set you free , But FIRST, it will probably Piss you Off !
Creativity is allowing yourself to make Mistakes, Art is knowing which ones to Keep !
The Saddest thing anyone can do , is push a Loyal Person to the point that they Dont Care Anymore
Never met a STRONG person who had an EASY past !
http://wiksnwudwerks.blogspot.com/
http://www.facebook.com/groups/GatewayA ... rAssembly/

This is awesome. I don't think I have ever seen a finish do that in my entire lifetime of projects.

My 2C. Whenever you are unsure what type of finish is on a guitar you are restoring/refinishing/overspraying you have to know what type of finish, pore filler or sealer is on the wood. In this case i'm guessing, and just guessing that the guitar had a poly finish and he tried to put lacquer over it. It appears as though the gold did bond to the wood as well....

If you are unsure what type of finish you have, you can always apply a layer of shellac. It is the only workable material that both poly and lacquer bond too.... I use it as a pore filler as well when guitars have been stripped because it gives you a nice clean prep surface and doesnt turn funny colors.