Is it worth the hassle of removing a polyurethane finish?

deja · #1 03-19-2011, 05:33 PM

I have an all laminate Yamaha that I would like to refinished in additional to resetting the neck. The problem is that it has a polyurethane finish, and I've read about the nightmares associated with removing poly finishes. I see this as a challenge and not necessarily an obstacle but then again I don't want to attempt the impossible. Is this one of those ill-advised projects? I don't want to end up with a Frankenstein monster.

gitnoob · #2 03-19-2011, 05:46 PM

Reseting a Yamaha neck and refinishing a poly finish have got to be the two hardest projects.

I've read that poly comes off with caustic chemicals or heat, both of which are dangerous and will damage the binding.

But if you're going to be removing the neck, then sanding may be an option. I've sanded off the poly finish from a neck before. The poly gums up the sandpaper pretty quickly, but it comes off.

The tough part of sanding is in the nooks and crannies, like the neck joint, but with neck off, it shouldn't be as bad.

Kitchen Guitars · #3 03-19-2011, 05:54 PM

You will. The finish will not come off even. You will end up with dark and light spots. Also the top Veneer is just that. Pretty easy to sand through.
Give it a shot. Especially if you are attempting a reset. Yamaha's are tough. Hey you can always paint it Gloss Black.

deja · #4 03-19-2011, 05:57 PM

That would be the plan - with the neck off. I think I would do the heat method as I wouldn't want to melt the plastic bindings with the chemicals but then that has the potential of other problems associated with scorching, etc. I suppose sanding would be the a decent compromise. With the neck reset, I plan to do the bolt-on conversion route rather than the "proper" method. It just makes more sense to me.

Anyway, thanks for the response gitnoob!

deja · #5 03-19-2011, 06:01 PM

Quote:

Originally Posted by Kitchen Guitars

You will. The finish will not come off even. You will end up with dark and light spots. Also the top Veneer is just that. Pretty easy to sand through.
Give it a shot. Especially if you are attempting a reset. Yamaha's are tough. Hey you can always paint it Gloss Black.

The veneer issue was my biggest worry. Maybe I'll just go with the neck reset.

macleay · #6 03-20-2011, 11:17 AM

On another forum, someone tried the heat gun method on a solid body and the glue holding the halves of the body got soft and the body separated.

random works · #7 03-25-2011, 07:54 PM

My dad showed me how to use a piece of glass from a broken bottle to scrap finish off of wood. You can get really good control. the thing is to get the pieces that have a slight curve and are big enough to hold. They do get dull after a while, but unlike sand paper will not gum up. I have used this method in the past, no gloves, never cut myself, and as far as I could tell, no dust in the air. Never tried it on poly though, just varnish.

Kitchen Guitars · #8 03-26-2011, 05:44 AM

A scraper kit from Grizzly is $12. No need to shatter glass. BTW ask for Grizzly's catalog. Every tool known to man. The guy that owns the company is a guitar builder and keeps about 20 pages of well priced Luthier supply in the catalog.

deja · #9 03-26-2011, 11:07 AM

Quote:

Originally Posted by Kitchen Guitars

A scraper kit from Grizzly is $12. No need to shatter glass. BTW ask for Grizzly's catalog. Every tool known to man. The guy that owns the company is a guitar builder and keeps about 20 pages of well priced Luthier supply in the catalog.

Thanks for the tip...just made a purchase. I've decided not to refinish but go ahead with the neck reset.

Guitar Hack · #10 03-26-2011, 09:33 PM

In a word, No. poly gets a bad rap but is a great finish for a guitar. Every bit as good as nitro if not better.

Bill Pillmore · #11 04-02-2011, 06:30 AM

Get a wood scraper. They are not expensive and the will work just fine. Need to take off the bridge too.

SwimTrunks · #12 04-10-2011, 08:44 AM

hey, im trying to gloss up an old beat up guitar for fun. can i use a spray aerosol polyurethane? if so, can i use water based or oil based?
This is just a fun project and doesnt have to be perfect, but i want it to look like glass and dont want the clear coat to just fall off one day.
im trying to find something I can buy at the local home depot.

thanks

Kitchen Guitars · #13 04-10-2011, 11:13 AM

Maybe. It depends on the original finish. It might bubble. Best bet clean it with Naphtha, lightly sand with a block and 320. Clean again. Spray on a layer and cross your fingers.