Official Luthiers Forum!
http://luthiersforum.com/forum/

When old finish becomes soft and gummy
http://luthiersforum.com/forum/viewtopic.php?f=10137&t=50909
Page 1 of 1

Author:  Tim Mullin [ Sat Aug 18, 2018 9:39 pm ]
Post subject:  When old finish becomes soft and gummy

We’ve likely all seen guitars where the finish, at least in areas that come in contact with skin, becomes soft and gummy. A really icky feeling.

I’ve had an enquiry from a player about refinishing a mid-70s Norman whose finish has become gummy. I haven’t seen the guitar yet, but these old Normans are not really worth putting a lot of money into. I’m wondering if there might not be cleaning methods that might remove/neutralize the offending grime and leave a non-reactive surface, without refinishing.

Naphtha is the obvious first candidate, I guess. I’ve also heard of Easyoff used for heavy-duty cleaning, but never had the guts to try it.

And maybe cleaning won’t restore an acceptable non-icky finish. if a respray is the only answer, what kind of surface prep?

Ideas for dealing with old gummy finish?


Sent from my iPad using Tapatalk

Author:  B. Howard [ Sun Aug 19, 2018 7:13 am ]
Post subject:  Re: When old finish becomes soft and gummy

Sometimes dirt and grime just build up on the surface making a sticky mess on top of the finish, naptha will clean that up.

Other times the plasticizers in the finish fail and the lacquer itself gets gummy. There is no hope that I know of besides refinishing to deal with this situation.

Author:  Tim Mullin [ Tue Aug 28, 2018 7:13 pm ]
Post subject:  Re: When old finish becomes soft and gummy

Well, attempts to clean the grung failed. In fact, I found that the finish was soft pretty much everywhere, was highly soluble in alcohol and absorbed water easily. The guitar is not super valuable, which may be a good thing, but was bought new by the client in the early 70s and in otherwise excellent condition.

So, the decision was made to refinish with nitro. Sanding produced nothing more than sticky balls of soft finish, so I resorted to furniture stripper. Not fun, but the dirty work is done. The original headstock decal was melting into the finish as well, so it’s gone, leaving a space for some custom inlay. The client is considering.

I hope I never have to use stripper again on a guitar!

Image


Sent from my iPad using Tapatalk

Author:  mountain whimsy [ Tue Aug 28, 2018 8:50 pm ]
Post subject:  Re: When old finish becomes soft and gummy

I feel your pain. Though multiply it by 100 and you have the stripping I had to do!

A 14' skiff. The varnish reacted badly with the epoxy. Stripped completely wtih gallons of stripper, revarnished. And still wouldn't harden. I had to strip the fiberglass, reglass, then finally varnish.

Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/