Trying to polish up a gloss black finish

mattyfez · 8 Jun 2013 at 12:16

Hey all,

Just wondering if anyone is good at polishing/finishing,

I'm trying to fix up an old guitar, and I've used a mild rubbing compound designed for car paint work, in combination with a microfiber cloth, and its come up quite well so far, but its got a lot of swirl marks in the light.

Is the compound too abrasive? any tips form anyone who knows about this stuff/

Thanks

doofer · 8 Jun 2013 at 12:19

Mustard.

Irish_Tom · 8 Jun 2013 at 12:27

As with polishing most things, it will probably require 'grading'.

Start with a fairly abrasive compound which will 'cut' the surface back to the bottom of the deepest scratch. You then use less-and-less abrasive compounds to remove the 'scratches' caused by the previous grade of abrasive until it's a perfect surface.

It could be done with polish or wet-and-dry sand paper.

The biggest problem/challenge with any polishing job is the thickness of the surface you're polishing. With cars you often have a very thin coat of actual paint (colour) and the rest is clear coat (a bit like varnish) on top. When polishing the car it's usually this clear coat you're polishing and if you get down to the actually paint you've gone too far.

mattyfez · 8 Jun 2013 at 12:41

Thanks, Yeh that makes sense, there's a couple of proper scratches that I'm not bothered about, but the main issue seems to be swirl marks in the lacquer / clear coat finish.

The problem I've found is looking for product to use.. cutting compounds/polishes don't really seem to be graded as to how aggressive they are.

I've just used some cheap 'carplan' rubbing compound so far.

Biohazard · 8 Jun 2013 at 12:51

Find paint restorer. Try that.

OT: I'm after a piano finish black gloss for some trim I'm painting but I can't figure out if to have a black base and lacquer or black lacquer? Anyone?

mattyfez · 8 Jun 2013 at 12:53

Maybe sandpaper is the way to go, as you can buy graded packs and work your way down...it's hard to know what your buying when you buy rubbing compounds/cutting compounds etc...I remember me and a friend 'lapping' a CPU a few years back, and we literally got a mirror finish on it. but that was just metal, we didn't have to worry about cutting through lacquer into the actual paint etc.

mattyfez · 8 Jun 2013 at 12:58

Biohazard said:
Find paint restorer. Try that.

OT: I'm after a piano finish black gloss for some trim I'm painting but I can't figure out if to have a black base and lacquer or black lacquer? Anyone?

I guess it depends what it is, I would guess black primer, black paint, then a few coats of clear would be the traditional way of doing it? not sure though.

Biohazard · 8 Jun 2013 at 13:00

matt black paint and clear lacquer?

mattyfez · 8 Jun 2013 at 13:04

Biohazard said:
Find paint restorer. Try that.
QUOTE]

Is that just a mild cutting compound though? that's the annoying thing, none of these products seem to be on a scale of abrasiveness..

Pinter75 · 8 Jun 2013 at 13:06

I have used Brasso, or Peak Metal polish to buff out stuff before. Will take out the small swirls.

Rub it in sections, let it dry then buff off.

Test on a part you can't see 1st tho'

Biohazard · 8 Jun 2013 at 13:24

mattyfez said:
Biohazard said:

Find paint restorer. Try that.
QUOTE]

Is that just a mild cutting compound though? that's the annoying thing, none of these products seem to be on a scale of abrasiveness..

Click to expand...

It isn't severely abrasive ie it won't make swirl marks worse, if you get car paint restorer, I have autoglym stuff it does work but requires a lot of effort.

If the scratches are too deep you'll need to rub it down and paint it.

mattyfez · 8 Jun 2013 at 13:41

Biohazard said:
mattyfez said:

It isn't severely abrasive ie it won't make swirl marks worse, if you get car paint restorer, I have autoglym stuff it does work but requires a lot of effort.

If the scratches are too deep you'll need to rub it down and paint it.

Click to expand...

Ok, sounds worth a shout, the stuff I'm using at the moment is like a thin paste, I've given it about 2 goes, an I think I need to step down in abrasiveness as I seem to be polishing swirl marks back in into the finish at the moment.

It looks great from some angles, but if the light catches it just right, it looks really bad