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I just received a couple of gorgeous sets of Mun Ebony (sorry, no photos yet). There are a few very small cracks that on initial inspection appear to run mainly outside the instrument outline. These run through the thickness of the back or sides. There is however one crack that appears to be a square inch or maybe more "flake" of wood slightly lifting from back at the center join, running parallel to the face of the back.

I'd really like to keep these sets if there is a good fix for them. Since I have little expertise in such fixes, I was looking for suggestions. Also in addition to general repair procedures, two specific concerns:

1) I imagine it would be best to perform a fix prior to stickering and storing so that the cracks don't spread, right?

2) Will there be a problem during bending if a side has a repaired crack near the edge?

Thanks in advance for your help!

If I were to do it myself without benefit of an answer from the larger forum here, I'd try thin CA on the crack. But, any voice of experience should supercede this guess.

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Jim Kirby
kirby@udel.edu

i've ca'ed through cracks on a variety of woods including ziricote, maple, mahogany and ebony and not had any problems, ...yet!!

have to admit to feelings of gross trepidation when it comes bending time though.

the chip crack you mention would be problematic on a side. i think i would find other uses in that instance. but on a back like you mention it should pose no problems. i would mark it though and try to have it on the inside if possible.

If the cracks are not opened up then just wick the crack with thin CA. If opened then rig clamps to pull them back in place , Do not over tighten, then wick in CA, Same on the chip, get it in place perfectly find some way to secure it that allows you to wick in Thin CA. you need the wood to seated perfect or you end up with a layer of CA as opposed to the CA infiltrating the wood.MichaelP39052.4747685185

Thanks for the responses so far.

A couple of additional questions have occurred to me ...

1) Regarding wicking in thin CA, I've done that on an Indian Rosewood guitar, and it worked perfectly. I also did that on a piece of Bubinga scrap I was hoping to salvage, but the CA didn't stick to it for anything, and the crack (which was easy to press together) opened right up after releasing the clamping pressure. Is there anything I can do if I have the same problem on the MUN EBONY?

2) I was thinking of flooding the cracks with a little Naptha or something in order to assess their full extent, since that wicks in and darkens the crack. Will any residues left behind by the Naptha hamper use of CA to later fix the cracks?

It shouldn't affect it.

Get some CA Accelerator from your local hobby shop. That will aid in getting it to stick to things. The hobby shop will probably sell CA of all types there also. If you don't have a hobby shop hear you, there's one not far from me that I know carries it all. I can give you directions to there, or get it for you.

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Get some CA Accelerator from your local hobby shop.

Thanks for the offer, Don, but I've got the Stewmac #10 and accelerator, so I should be all set. Now when using accelerator for cracks, isn't that going to kick the CA before it has a chance to wick all the way into and down the crack?

CA first then spay with accelerator.

Yes apply the Thin CA first, it will wick almost instantly then spray the accelerator

Now someone please correct me if I'm wrong here, it's happened many times before

Doesn't the CA accelerator make the CA more brittle? And why would you really need to accelerate the CA, you'd really want it to wick in as much as possible and let it do what it does all on it's own. I mean, 10-15 seconds is quick enough yes?

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The only reason that accelorator was suggested was that Peet was having issue with the wood oils interfering with the CA setting up. I have used CA on Malaysian Ebony with no Issues. I use no accelarator ever if I can help it. But It is only giong to affect the CA on the surface. The CA that has wicked into the seams will not be affected.

sometimes ya gotsta read the whole book eh?

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My Facebook Guitar Page

"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson