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Fixing a Top Crack
http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10122&t=29983
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Author:  Scouter [ Fri Nov 19, 2010 10:40 am ]
Post subject:  Fixing a Top Crack

I've taken some time to poke about the various OLF forums and, although I've found bits and pieces of what I'm
looking for, I've not found the complete discussion.

So... I thought I'd come outright and post the question (and a couple of pics).

The Issue:
I've 'inherited' a Revival RG-27 in near new condition with one problem: It comes with a top crack running from
the bridge to the binding above the block.

As far as I can tell (from my significantly under-trained ear) the crack doesn't affect the 27's sound. However,
I've got to believe that not addressing the crack properly in the near term will result in it becoming
a) more obvious as dust & dirt particles and oils & skin flakes are introduced into it over time thereby darkening the
line, and (much more importantly)
b) potentially a larger crack with subsequent sound/playability problems.

Here are two images of said crack.

Image

Image

Now, admittedly, the 27's are not expensive guitars (~$650 MSRP); so I hesitate to have a professional Luthier fix it
for $300 or so (just a guess, but everything seems to cost more in the Bay Area...) And when you couple the guitar
value with Pro-Luthier costs to fix it with my wood shop, my years of experience in furniture construction and wooden
toys, and the few articles I've read on this forum (and other sites), I'm lead me to believe that crack fixing - "non-
structural"
crack fixing - isn't rocket science. So, well, I thought I'd give it a go myself.

What I'm looking for:
Is there a forum discussion (or group thereof) that would provide sufficient direction for my to take a run at fixing the
crack? Or am I simply daft for even suggesting doing it myself? ;-)

Thx in advance for your consideration.

Thomas

Author:  Barry Daniels [ Fri Nov 19, 2010 4:01 pm ]
Post subject:  Re: Fixing a Top Crack

You should be able to do this without too much hand holding. The basic process is to rub some glue into the crack. Hot hide glue is the preference but Original Titebond is an acceptable substitute if you are not setup to do HHG.

The crack appears to be fairly closed and clean so that makes things a lot more simple. Take the strings off the guitar and place your arm in the guitar, putting some finger pressure under the crack. The soundboard should rise a little with the crack opening up. At this point you can run a bead of glue down the crack and rub it into the crack with your finger while you continue to press under the soundboard opening the crack. Massage the glue in for 15 seconds or so then release the pressure under the soundboard. You should see a little glue squeeze out of the crack which is a good indication that you got good glue penetration. Squeeze out on the bottom side of the top will indicate full penetration, but that isn't always seen. Use a damp rag to clean all traces of the glue off the top and any that squeezed out on the inside. Assuming the crack is really tight, you are basically done. Otherwise a padded clamp across the lower bout might help tighten up the crack marginally. Don't overdo the pressure on the clamp. One last thing to check before the glue sets up is the levelness of the two halves of the top. If you can feel any uneveness, try to press the parts into better alingment.

It is not necessary, but the addition of some cross grain spruce cleats on the inside will provide a little insurance in keeping this crack from reappearing. If you do this, wait until the crack has been glued, then add the cleats. Two or three would suffice.

Author:  Scouter [ Fri Nov 19, 2010 5:18 pm ]
Post subject:  Re: Fixing a Top Crack

Thx Koa! Much appreciated. This will be my holiday weekend project.

As for glue... After watching several interesting videos on HHG, I'm definitely
not set up for that (yet).

What about the Titebond HG? Is it all that its billed or should I steer clear and
stick to the white glue for this application?

Thx again!

Thomas

Author:  George L [ Sat Nov 20, 2010 6:50 pm ]
Post subject:  Re: Fixing a Top Crack

Thomas,
I've never used Titebond's bottled liquid hide glue, but from what I've read it has not met with great approval within the guitar-making community. That said, I have seen references of it working perfectly well, especially in situations such as your cracked top. As you have probably noted in your research, one beneficial aspect of animal protein glues is that they stick to themselves, which may allow you a greater chance of success should the crack open again in the future, resulting in you having to repeat the repair process Barry described above.

Author:  Scouter [ Tue Nov 30, 2010 12:54 pm ]
Post subject:  Re: Fixing a Top Crack

Thx for the insight George. Instead of rushing into a fix I've pushed the effort to the back
burner while I come up to speed on HHGs. In fact, I've procured the items necessary (or so
I believe...) and will order granules in the next day or so.

I've been scouring sites on HHG application and usage tips/tricks and will give it a go after
a few tests and non-instrument applications. Better to get it as close to correct on the first
attempt as I can, right? Thx again for the insights!

An aside: I've been looking through the forum at some of the work; keying specifcially on the
inlay. Wow. Some of it is über impressive! Absolutely works of art.

Author:  Mike R [ Thu Dec 09, 2010 9:45 am ]
Post subject:  Re: Fixing a Top Crack

Scouter,
If you are impressed with what you have seen on this forum, go over to the Kit Builders Forum. Those guys are building some beautiful guitars. With what you would pay for one of those Revival guitars, you could buy a nice kit and build your own. Minimal tooling required.
Mike R.

Author:  jac68984 [ Fri Jan 21, 2011 12:35 pm ]
Post subject:  Re: Fixing a Top Crack

Titebond Original will work fine if you have HHG reservations. I really like HHG, and it would do well to fix your crack, I'm sure. But, you can slightly water down Titebond Original so that it flows a bit better and fix as per Barry's instructions. I've done it before and it worked fine. The cleats, while maybe overkill, are a good recommendation I think. And while your in the repair mood, the wouldn't take long to glue in. You know . .. an ounce of prevention and all.

Aaron Craig

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