White haze on finish, how do I get rid of it?

[evantide]

MyTaiwan hand made Yamaha classical GC-7, has developed a white smoky haze on the finish, a couple of spots like a thumb size remain clear as original, but most of the back and not as much on the sides, has this film. I don't know if it's humidity problem, nor do I know the finish they used. I assume made late 70s or early 80s since it was made in Taiwan.
I tried everything in small area, dunlop 65, old english oil, waxing, etc. to no avail.
Any help will be appreciated.

[mirwa]

Hi,

Do you have any photos, its hard to guestimate via an internet forum on the best of times, but a photo goes a long way in diagnosing.

Steve

[Kitchen Guitars]

Try Naptha. But, the Yamaha glop on finish is notorious for white air? build up as the guitar gets older. At the neck joint is the worst spot usually. Got a few great Yamaha's cheap because of it.

[Ned Milburn]

Originally Posted by evantide

MyTaiwan hand made Yamaha classical GC-7, has developed a white smoky haze on the finish, a couple of spots like a thumb size remain clear as original, but most of the back and not as much on the sides, has this film. I don't know if it's humidity problem, nor do I know the finish they used. I assume made late 70s or early 80s since it was made in Taiwan.
I tried everything in small area, dunlop 65, old english oil, waxing, etc. to no avail.
Any help will be appreciated.

Is it a haze in the finish, or a film on the finish??

Well, I expect it is within the finish, since surface products have not helped.

Sometimes, humidity is trapped within a finish and this can cloud or whiten the finish. Very common on coffee tables when people put a hot wet cup down without a coaster.

This can be sometimes fixed somewhat by dry ironing a white T-shirt on the trouble spot.

However, this operation on guitars becomes more delicate and probematic. First, the guitar is made with thin woods (and many Yamahas have plywood in them). The heat can soften the glue and cause joints to creep (move slightly), or in worst case scenarios can open up glue joints. Also, since most guitars are finished with a mirror-like shine, the ironing technique could lead in certain cases to some transfer of T-shirt weave impression into the finish.

If you had a photo, you may get some more comments. There is a good chance that the best to be done is to accept it and live with it as is.

[John Arnold]

Moisture is the usual cause of finish cloudiness. Unfortunately, I have not found a way to remove it from the Asian polyester finishes without a total refinish. If the finish was lacquer, I would simply wipe it with denatured alcohol.

[Sperry]

Collings uses NOVUS 2 on their nitrocellulose finishes.

I've used Novus, after naphtha. Also I've experimented with acetone, rubbing alcohol, & gin.

[Kitchen Guitars]

Originally Posted by Sperry

Collings uses NOVUS 2 on their nitrocellulose finishes.

I've used Novus, after naphtha. Also I've experimented with acetone, rubbing alcohol, & gin.

Is the Gin used for the cleaning process or to keep your attention on the project?
As an aside. I got my hands on some local moonshine to mix / melt Shellac. I didn't have the heart to tell the moonshiner that it wasn't high enough octane lol

[Sperry]

Originally Posted by Kitchen Guitars

mix / melt

Melt is right. I used gin to remove varnish along a seam of a violin, then mixed a pinch of potting soil, linseed oil, and a drop of varnish (my famous "Oil & Soil" finish) to recreate an Olde World authenticity.

I've found acetone works great on the super-thick finish of a cheap guitar. Removes just about every mark. ALWAYS test on a small spot around back.

[Ned Milburn]

Originally Posted by Kitchen Guitars

As an aside. I got my hands on some local moonshine to mix / melt Shellac. I didn't have the heart to tell the moonshiner that it wasn't high enough octane lol

Same here. I (and friend) ended up drinking it!! ;-)