Repairing scratches in black poly finish

idoru · #1 11-13-2006, 05:35 PM

g'day guys - did a search, some useful info but nothing specific to my problem:

I have a '93 SSD with a black finish - nothing shows scratches like black, as the rough surface inside the scratch tends towards a white colour. I'm trying to sell it, and obviously I want it looking as good as possible. I've tried buffing the scratches out, but they're just a bit too deep.

Sanding is apparently very difficult, but maybe in spot areas only it won't take too long? Would the super-glue fill technique work on black?

I can always experiment on the back of the bass first, but I figured I'd tap the vault of knowledge here

cheers

**Mickey Shane** · #2 11-15-2006, 09:02 AM

I bought a black bass from a cat in Nawlins that had been 'touched up'. It looks fine from three feet away, but up close you can tell that the finish has been repaired.

I wish he hadn't done that. I much prefer the scratches to the touch up. Your bass that you want to sell is 13 years old. It should have scratches. It's a relic.

Just my opinion, as always.

idoru · #3 11-16-2006, 04:11 AM

heh - maybe not a relic yet, if the arbitrary definition of vintage is 25 years or so. I just want the best price I can get for it

It's not so much a refinish that I'm aiming to do - if my hunch is correct, sanding down to take out the scratches should leave plenty of the original finish. We're talking fractions of a millimetre here, and there's no bare wood visible at all. Seeing as how the Re-Ranch forums are bugging me out, I'm just going to try a spot on the back of the body and see how I go. I'm aware poly is a bitch to sand, but I only work part-time. Time is on my side, yes it is...

202dy · #4 11-16-2006, 06:50 AM

Rubbing out (sanding) is the only way to get to the bottom of the scratches. And that is exactly what you're trying to do. As you indicated, the problem is burn through or exposing bare wood. When some instruments are painted the first couple of coats are clear coats. This is a problem when you burn through because the remedy is to paint the body.

Be careful. Start with 600 grit and see where that takes you. If you've never done this before find some painted items-or better yet, pick up a piece of junk guitar at a flea market for a couple of bucks-and practice. Learn to estimate when to stop the rub out while you can barely see the scratch(es) and begin the buffing process. Why? Because sometimes the burn through doesn't occur you've almost finished buffing. It is frustrating when this happens and it's all too easy to do.

Good luck.

Hambone · #5 11-16-2006, 07:11 PM

Quote:

Originally Posted by 202dy

Rubbing out (sanding) is the only way to get to the bottom of the scratches. And that is exactly what you're trying to do. As you indicated, the problem is burn through or exposing bare wood. When some instruments are painted the first couple of coats are clear coats. This is a problem when you burn through because the remedy is to paint the body.

Be careful. Start with 600 grit and see where that takes you. If you've never done this before find some painted items-or better yet, pick up a piece of junk guitar at a flea market for a couple of bucks-and practice. Learn to estimate when to stop the rub out while you can barely see the scratch(es) and begin the buffing process. Why? Because sometimes the burn through doesn't occur you've almost finished buffing. It is frustrating when this happens and it's all too easy to do.

Good luck.

I wouldn't sand it in this case. The chance of creating an uneven finish is very high and then a real repair would be needed. I would jump straight to the buffing compounds and a power buffer. You would be surprised how well you can make a decent finish pop. I use 3 3M grits and can really get a deep shine. It will buff over the scratches and make them black again. It IS a 13 year old bass and imperfections are expected but you can make them hard to spot.