Removing a Poly Urethane Finish

[saxnbass]

What would you suggest for removing a Poly finish? I have a cheap-o that I want to take the finish off of, but don't think it's worth it to have it done by a pro so I've decided to do it myself. Any tips? thanks.

[Yell03SpecV]

IIRC, both Grainger and McMaster Carr have urethane strippers. not sure how badly it would damage wood though, if at all.


Otherwise, wait for someone with a helpful response, lol.

[62bass]

The factory polyurethane finishes are 2 part finishes that cure very hard. They are not at all easy to remove like the polyurethane finishes you buy in a can for home use. I haven't found a stripper that will touch it. Some say a product called "Aircraft Stripper" will remove it. I don't know as I couldn't find any here. Sanding it off takes forever. That stuff is tough. The best method I've found is a flexeble paint scraper and an electric heat gun (about $40) I stripped a few basses this way. There's still some sanding to do after you melt off the finish with the heat gun, but it's not nearly as bad. If you use a heat gun, you should do it outdoors as the fumes are toxic and will set off all the smoke detectors.

It's a lot of work and worth it if the wood underneath is nice. Then you can do a natural finish. Otherwise, it's a repaint.

[keyboardguy]

I used Formby's paint and poly stripper. It 'kinda' worked.

n the end I got out my electric sander, bought 50 grit sandpaper, and went to town.

Be prepared for a long haul though. It was worth it; I tung oiled it and it looks great!

Mike

[blipndub]

Jasco works but it still takes about a week of setting and scraping, setting and scraping. You might want to just sand off the finish but it will make a big mess and you should have proper respirator equipment.

[62bass]

Originally Posted by blipndub

Jasco works but it still takes about a week of setting and scraping, setting and scraping. You might want to just sand off the finish but it will make a big mess and you should have proper respirator equipment.

That's why I used the electric heat gun. You can get most off in less than an hour. Then do the corners and crevices with sandpaper.

The worst was my 70s Fender. The heat gun got the coloured finish off without too much trouble but wouldn't lift the clear sealer, a polyester resin. Heat, enough to burn the wood, wouldn't bother it. That took a lot of sanding, starting with 36 grit and working finer. I had to make up sanding tools from plastic drain pipe to get into the curves. Ordinary sandpaper wore out too quickly. I finally got some belt sander belts with a ceramic grit and that held up. it was a good afternoon of hard work.

[BassyVick]

how bad is the dust from sanding a poly finish, hopefully not to harmful i did use a wet rag and a breathing mask, the breathing mask was, however, for non toxic

any thoughts?

[202dy]

Heat is the way to go. A heat gun will minimize the time and pain. If there is a chemical answer I, for one, would like to hear it. Aircraft stripper will not lift this finish.

As far as the '70's Fender sealer coat goes, back in the '70's I used an acetyline torch to crackle the finish and picked the flakes off with a sharp, stiff paint scraper. You have to move fast or the wood will char in short order. Takes about an hour to an hour and a half to be ready to sand.Obviously, today we would not be stripping that layer off because of the value of the guitar in the marketplace.

[62bass]

Originally Posted by BassyVick

how bad is the dust from sanding a poly finish, hopefully not to harmful i did use a wet rag and a breathing mask, the breathing mask was, however, for non toxic

any thoughts?

Oh no. Did you already inhale some? I figure you've only got a few days left at best. Better send me all your gear. I'll look after it in your memory.

Seriously, as long as you're not inhaling or otherwise ingesting the dust you're fine. Using a heat gun for stripping, toxic fumes are released. You'll want lots of ventilation for that.

Don't bother with commercial strippers. They won't work. Either do it the hard way, sanding all the way, or get most of it off with heat, then finish up with sanding. The heat method is much faster. If you use heat, do it outdoors. The electric heat guns are fairly cheap now and are easier to use than a torch with open flame. That works but you can easily burn the wood if not careful.

Either way, it's a lot of work. Luckily, when I did it on my Fender I found the body was ash with an attractive grain. It took me the better part of 2 days to get it ready for refinishing. I wouldn't bother on a cheap bass.

[elwood]

Originally Posted by GlennW

Advance Auto and/or AutoZone carry Aircraft Stripper.

Zip Strip is another good product.

FYI the product is called, "Aircraft Remover". Some auto parts places carry it. It runs around $35-40 a gallon, which is enough to do about 20 basses. The main ingredient is methylene chloride. Don't use it if you're pregnant.

I used it to strip polyurethane from a 1990 Yamaha BB5000A. It took a number of applications and a lot of time, being careful to wait between applications because it had a tendency to get the wood wet after prolonged application. The plastic scrapers I used to remove the stripping goo lasted a little while before dissolving themselves. It still required a fair amount of patience, finesse, and elbow grease to remove that PU- it really does not want to be removed.

A luthier who's been around a while said he used to use a torch. I suppose this would be less hassle, if you are good enough not to burn the wood up while toasting the finish.

[BassyVick]

Thanks 62 bass for the advice

i had to carve the horn on my TRB6II i didn't like the way it felt across my chest