Refinish and Black Mold?

GutOil · #1 02-24-2010, 02:47 PM

Hi, I'm refinishing a double bass. After stripping the lacquer I've discovered black areas that seem to be black mold on the front and back (not sides). I'm wondering if the mold was trapped under the dried lacquer during the finish process. I purchased the bass new a few years back from a rep US shop we've all heard of. Now I'm curious how to properly remove this.

Also, to elaborate, althought the purfling was obviously visible through the old finish, I never noticed the black spots until the old finish was removed.

arnoldschnitzer · #2 02-24-2010, 04:13 PM

I don't think that's mold. I think it is embedded stain, used to color the wood. If I'm right it will probably not be possible to remove it.

ctregan · #3 02-24-2010, 04:33 PM

You could try a solution of oxalic acid (white powdery stuff) mixed with hot water, let it sit on the stain a wile and soak.

Try a small test area first.

**Matthew Tucker** · #4 02-24-2010, 09:10 PM

Are you hoping to get a blonde bass out of this?

GutOil · #5 02-25-2010, 08:48 AM

I was hoping to do a blonde finish. There's got to be some off-the-shelf solution to lift the stain.

basswraith · #6 02-26-2010, 09:56 PM

Arnold what do you think of wood bleach? It comes in a 2 part system. Some time you can get in commercially. Ever try it? What about CLR?

You may just have to revarnish the bass dark enough to make those dark areas blend away.

**Matthew Tucker** · #7 02-27-2010, 05:53 AM

I don't think you'll get a nice blonde finish. make life easier for yourself and go light brown.

arnoldschnitzer · #8 02-28-2010, 12:57 PM

Quote:

Originally Posted by basswraith

Arnold what do you think of wood bleach? It comes in a 2 part system. Some time you can get in commercially. Ever try it? What about CLR?

You may just have to revarnish the bass dark enough to make those dark areas blend away.

Wood bleach can help lessen natural pigment in the wood, or reduce mineral stains, but I don't think it does anything with old stain that has been applied directly to the wood and has sunk into the fibers. I think the only way to remove that is to scrape or sand past it, which will run the risk of destroying the instrument.

Forget the blonde finish.