Question: Repairing scratch on LSI piano black finish

[Mike in Ohio]

Hello all - new here but have been a polk lover for 15+ years! Just scored a beautiful pair of LSI9's to put together a new system. The top of the right speaker has a nasty scratch in it. I'm guessing it's a laquer finish so a careful sand with some progressive sandpaper up to 2000grit then relaquer? OR would you consider using automotive scratch removal and buff it out that way?

Anyone cross this road before?? Any advice appreciated.

Mike

[F1nut]

How deep is the scratch? Let's go by the following;
Light surface scratch - can see it, but only up close. Doesn't snag a fingernail dragged across it.
Medium scratch - more obvious to the eye, slightly snags the fingernail.
Heavy (deep) scratch - very obvious to eye from a distance, snags and holds a fingernail.

Also, how long is the scratch?

[Upstatemax]

I'm going to guess that a "nasty" scratch falls under the heavy scratch label...

a full sand and repaint would be my dead last option.

You could always try touchup paint and buff with rubbing coumpounds to get it smooth and polish it up. Will still be somewhat visable but much less involved and less chance of further damage to the speaker.

[Mike in Ohio]

I'd definately qualify it as a heavy scratch - it's about 5" long. It appears to just be in the clear finish vs deep enough to be in the black pigments - hence the rubbing compound solution idea. When I was going to sand, I was going to start with pretty fine grit (probably 400 or so) on the end of a pencil so I only affected the scratch area and releveled everything.

That sound about right?

[F1nut]

NO, don't do that. I'm short on time, more later.

[Mike in Ohio]

Bump

[F1nut]

I forgot about this, sorry.

When a scratch is deep, you can't sand it out without leaving the area lower than the surrounding area. Not to mention the high probably that you'll sand though the color. You need to build up the scratch. Burn in is the best way to do that, but if you've never done it you're much better off taking it to a professional. Might run $200 to $300 depending.

[Evrythngmatters]

I was going to tell you how but I was timing out here every time I typed it up. Two ways, I can give you my # and you call me. I will explain everything to you on how to fix your issue or take it to a piano rebuilder. They have to fix scratches like this all the time and pretty easy to fix after you have done it a few times. Either way, you will get it done. Piano rebuilders would be THE person I would goto first. Your finish is not very hard to fix really.

[F1nut]

There is no such thing as timing out here.

Why piano restorers/refinishers, any furniture restorer/refinisher would be able to fix it or are you thinking that because it is a black lacquer type finish that a piano guy would have more experience? Perhaps you are not aware that the typical black lacquer finished piano has nothing to do with lacquer. It is actually a polyester finish, which is a real bitch to fix properly.

Anyway, I'd love to hear your ideas on how to repair this damage easily. Hell, I might learn something.

[Evrythngmatters]

By the time I typed it up and went to finalize it a screen came up asking me to log in again. I guess it timed out or something. That is what I meant.

I did some basic piano rebuilding back in the day many years ago. The way we did it was to
get a razor blade knife and cut out the offending area. We just cut wide and long enough to
give the deep scratch/gouge clean lines. Make sure everything is cleaned out of the scratch/
gouge. Next up we melted a lacquer stick of the same color (polyester actually and some
times you had to mix colors which can be a challenge)) into the affected area until it was 1-1/2
inches higher than the affected area itself. We let it cool which was pretty fast then we
sanded it down. We used sand paper wrapped around a wooden block to sand initially till we got
down to about 1/4" from flush. Next we would switch to a very fine grit sandpaper with water and
sand till flush. Yes, some of the sanding does rub onto non affected areas but if you do it
lightly enough with the right sand paper you are fine. After everything is sanded and flush
we would use a high quality wax with NO abrasives such as Meguires or Mothers (only certain
ones though) and buff to a high glass. Wax was put on wet and taken off wet with a variable
speed professional buffer. If you stay in one spot to long when buffing you will cause an indention,burn a
hole in the finish or even worse. Not a hard process by any means after you have done it a few
times. Hence why I suggested a piano rebuilder. This is something they do day in and day out. Only thing I will say though is that unless you do the whole speaker the affected area will look really good but if you look at it in bright light at just the right angle you will be able to see where it was a little.

[F1nut]

What you are describing is called a burn in repair, which is what I stated earlier. It is not easy to do properly, requires special tools, materials and is best left to a pro.

BTW, you don't need to cut anything to get clean lines. One of the beauties of burn in repairs is they can be done to the scratch as is with excellent results.

[Evrythngmatters]

It is not easy to do properly, requires special tools, materials and is best left to a pro.

BTW, you don't need to cut anything to get clean lines. One of the beauties of burn in repairs is they can be done to the scratch as is with excellent results.

I agree with the leave it to a pro but no special tools are needed imo. Nothing more than a hand held torch,lacquer stick which is not hard to find,block of wood,sandpaper,water,wax,and a buffer. I was always taught to cut the offending area out to minimize future cracks. There are always super small cracks you cannot see with the naked eye than can run like a crack in a winshield over the years. Changes in temperature cause this and while they are very minimal inside a home they do occur. Like how you never place a piano near a heat/ac vent in a home. It will and does screw up the soundboard and tuning.
I did this repair so many times and while the first few times I was supervised, the third time and after I was on my own. One of a few things that are almost a no brainer that even someone not skilled in piano rebuilding can do. I did alot of the spraying,stripping,polishing,fixing Ivory on the keys,stringing,felt work,minor action work etc. I did do lots more but rebuilding a piano is like watching grass grow, boring.

[cnh]

Evrtngmatters...

When you log in, click the 'Remember Me' box next to your name box and you won't 'time out'!

cnh

[Mike in Ohio]

Great - thanks for the input - I'm an experienced woodworker but just never have used burn in sticks before. Since the scratch into all the way into the wood I believe I need to use clear. I have a good professional random orbital porter cable sander I've used refinishing my car so it sounds as if that will work fine when I get to the polish stage. I'll keep you filled in on my progress!

[chadam44]

Wet and dry sand paper, as high of a grit rating you can get. Sand it down, then tape off the speaker and respray the side with black enamel paint until you get it back to flush (sanding down and repainting a few times.) Then hit it with a few coats of clear, high gloss enamel and you are good to go. Might not be as nice as the original piano black, but I can still see my reflection in the sides that were repaired. Only runs about $20 to take care of it too.