Cracked Lacquer Finish Repair?

TEST ON SCRAP FIRST! If your question is about repair work, either regluing or refinishing, please post it in our Repair Section.
Post Reply
John E Giarrizzo
Posts: 140
Joined: Sat Feb 04, 2012 10:17 am

Cracked Lacquer Finish Repair?

Post by John E Giarrizzo »

I did a restoration on my Dad's guitar about twenty years ago. It was in pretty bad shape. Neck was separating. Finish really bad. Frets worn and falling out. Tuning knobs crumbling. I think this was the one he carried around when serving in WWII. Went through The Battle of the Bulge. Some of my earliest memories are playing with it when I was 3 years old or so (1950).

Reset neck. New frets. Refinish.

Problem being this was before I knew about humidity. It was done during the winter months. Extremely low humidity --- probably 20 percent or less. Over the years the finish has cracked, I assume due to the wood expanding. I don't think the wood is cracked, just the finish.

Can this be repaired? I hope so --- it is one of my most prized possessions

Thanks,

John
JEG_100_3932.JPG
JEG_100_3941.JPG
JEG_100_3942.JPG
JEG_100_3944.JPG
Steve Senseney
Posts: 673
Joined: Fri Jan 06, 2012 2:45 pm

Re: Cracked Lacquer Finish Repair?

Post by Steve Senseney »

Do you have any idea what kind of finish you applied?
John E Giarrizzo
Posts: 140
Joined: Sat Feb 04, 2012 10:17 am

Re: Cracked Lacquer Finish Repair?

Post by John E Giarrizzo »

All I know is that it was a "guitar lacquer" that I purchased from a local guitar repair shop. It was definitely a lacquer.
John E Giarrizzo
Posts: 140
Joined: Sat Feb 04, 2012 10:17 am

Re: Cracked Lacquer Finish Repair?

Post by John E Giarrizzo »

P.S.

The guy bought his lacquer in bulk, and poured some in a plain glass jar for me, which is why I don't know what brand or type. It thinned and cleaned up with lacquer thinner.
Michael Lewis
Posts: 1474
Joined: Thu Jan 12, 2012 1:22 am
Location: Northern California USA
Contact:

Re: Cracked Lacquer Finish Repair?

Post by Michael Lewis »

From seeing the pic of the back it looks like there are some cracks in the wood that have been there a long time and accumulated stuff in them, which is why they appear darker than the surrounding surface. It is less easy to say about the front because of the contrasting linear arrangement of the wood grain which tends to hide things a bit, but I suspect it is in much the same condition as the back except for the difference between the wood species. You can make it very nice again, but it will never be new again. Some of the discoloration will show.
User avatar
Barry Daniels
Posts: 3186
Joined: Thu Jan 05, 2012 10:58 am
Location: The Woodlands, Texas

Re: Cracked Lacquer Finish Repair?

Post by Barry Daniels »

Anytime you see cracks following grain like this you can rest assured that the wood is also cracked. The appropriate repair would be to fix the wood cracks with reinforcement patches and splints if necessary, then touch up the finish. But since this is not an original finish, it would not lessen the instrument's value to strip the old finish and refinish it after fixing the wood cracks. And this time, you can use a more flexible finish that may hold up better.
MIMF Staff
John E Giarrizzo
Posts: 140
Joined: Sat Feb 04, 2012 10:17 am

Re: Cracked Lacquer Finish Repair?

Post by John E Giarrizzo »

Thanks for the replies.

Refinishing I think I could do. Fixing the cracks? That may be a job for a pro. Can the they be fixed without taking the top off?
User avatar
Barry Daniels
Posts: 3186
Joined: Thu Jan 05, 2012 10:58 am
Location: The Woodlands, Texas

Re: Cracked Lacquer Finish Repair?

Post by Barry Daniels »

Yes, no need to repair top.

Edit: I meant, no need to remove top in order to repair it. But the repair would be more complicated since you don't have a larger soundhole, only f-holes.
MIMF Staff
David King
Posts: 2690
Joined: Sat Jan 07, 2012 10:01 pm
Location: Portland, OR
Contact:

Re: Cracked Lacquer Finish Repair?

Post by David King »

or remove the top...
John E Giarrizzo
Posts: 140
Joined: Sat Feb 04, 2012 10:17 am

Re: Cracked Lacquer Finish Repair?

Post by John E Giarrizzo »

Is a complete stripping and refinish required?

Or if someone knew what they were doing --- could just those areas be touched up? Which would be beyond my abilities.

Thanks again for the help.
John E Giarrizzo
Posts: 140
Joined: Sat Feb 04, 2012 10:17 am

Re: Cracked Lacquer Finish Repair?

Post by John E Giarrizzo »

Oops --- Just read the forum section definitions. I posted this in the wrong section. Sorry about that Charlie. Should have been in Repair section. But you guys were kind enough to answer anyway.
Michael Lewis
Posts: 1474
Joined: Thu Jan 12, 2012 1:22 am
Location: Northern California USA
Contact:

Re: Cracked Lacquer Finish Repair?

Post by Michael Lewis »

It would probably be easier to remove the back instead of the top if you need to access the inside. To remove the top you just about have to remove the neck first.
David King
Posts: 2690
Joined: Sat Jan 07, 2012 10:01 pm
Location: Portland, OR
Contact:

Re: Cracked Lacquer Finish Repair?

Post by David King »

John,
If you aren't too fussy about the results you could certainly fix the cracks and drop-fill over them over time as the new lacquer shrinks.
If you weren't happy with that you can always strip and refinish.
If the cracks are old and dirty you'll need to clean them up with a solution of bleach and water first Once that's thoroughly dried you can thread your patches onto a needle and thread that you've pushed through each crack from the outside and retrieved from the inside through the F-hole. Once the patch is past the needle and onto the thread you cut the needle off the end and tie a knot at the back of the patch. Apply glue and then pull the patch tight to the inside. I've never done this but I've seen it done. Use small neo magnets to help with the clamping and/or retrieving the needle. I'd set up a cctv inside to monitor progress if you have that capability.
User avatar
Barry Daniels
Posts: 3186
Joined: Thu Jan 05, 2012 10:58 am
Location: The Woodlands, Texas

Re: Cracked Lacquer Finish Repair?

Post by Barry Daniels »

Yes, that would be the way to patch the cracks without taking off the back or the top. I have some old tuners mounted to a small block of wood used to clamp the patch in place after being threaded though the soundhole on a small diameter ball-end string.
MIMF Staff
Post Reply

Return to “Glues and Finishes”