Glueing a crack in a one piece body

[JohnnyThul]

Hi guys,

I just worked a little more on my brother's guitar and smoothed the sides a little. During that I noticed a crack in the body.

Now, is this something to really worry about?

It's a one piece body of figured ash. It could be, that it cracked due to too much pressure during glueing the top to the body. I flooded the crack with thin super glue.

Anything I should be aware of? I hope it's not too Bad, as this is a guitar for my brother and at least once I wanted to try, to make it close to perfect...

 

[guitarbuilder]

Cracks that run perpendicular to the grain like that are from drying. I think you did what you can do there. Those kinds of checks generally are at the ends of the planks. I don't think clamp forces of gluing on a top would cause that unless you were trying to straighten out a warp in the main blank.

How to Identify Lumber Defects — Kaltimber

 

[JohnnyThul]

Thanks a lot for your comment, that is quite a relief!
The board I cut the body from had several cracks from drying, but I thought I would have avoided them when I cut the body. Iuse a pretty heavy press to glue tops to bodies, therefore I thought it could have been caused by that. The top and body were not 100% flat, but pretty close to it.

 

[guitarbuilder]

Well I suppose it is possible that that press could have exaggerated the check, but you may have noticed it then or it only appeared visable after sanding. It happens. I've had it happen as have others.

 

[Blue Bill]

I hate to say it, but you may want to consider discarding that body and starting over with an un-checked one. I was taught this the hard way; a more experienced woodworker saw me attempting to save a desktop from a check like that one, on a desk I was building. He was correct. no amount of glue, epoxy, resourcenol, etc., would get an end grain check to stop.

If you are going to finish it with opaque paint, you may get away with it, or, it may crack the paint after a year or so.

You may have a chance with a bow-tie, but that will leave a seam that probably will be visible. Good luck, keep the pictures coming.

 

[Boreas]

Where is the crack? Close to a stress point? It could certainly get worse and crack any future finish. But it may be fine. It's a gamble, but not a wise one. If you have good access to the interior of the box, I would at least cleat it. I would even consider removing the top to cleat it. But I suspect there are other checks waiting to happen after you spend weeks finishing it.

If it isn't too much of a PITA, start over. Perhaps save this one for a few years and see what it does. If it stays stable, then throw on an opaque poly or epoxy finish and build another.

 

[Peegoo]

How long has that board been outside of the log? Was it stored in a damp location before you used it for this project?

 

[JohnnyThul]

Hi guys, thanks a lot for your input!

As for the bowtie, is that really necessary, as I have a 18mm White Oak Top glued to the body, shouldn't that prevent the crack from getting really bad?
The Log where I cut the body from sat around my workshop for about 4 years. I bought it from a source who stored the wood for a very long time and I have used this wood for 2 other guitars, with no problems at all so far.
The finish will be either Truoil or wipe on poly, and if I cannot hide the crack 100%, that is not so much of an issue for me, as long as it is stable.
To start all over, well, that would be tough, I have 4 weeks into that build already

 

[Blue Bill]

Wow, that's beautiful. That's about where I was with my desk project, so I forged ahead too. So far, the client hasn't complained about the crack, but it haunts me a little. That grain is insane!

 

[JohnnyThul]

The crack is roughly an inch left to where the strap button would be located.

 

[Boreas]

The crack is roughly an inch left to where the strap button would be located.

Hmmmm....

 

[Peegoo]

Damn the torpedos! The wood seems like it would be dry enough.

Cutting the body to shape probably released some internal tension in the wood (common in figured hardwoods). I say press forward.

That's going to be really nice.

 

[RickyRicardo]

When I make a body it's usually with wood I've had for a few years and I get a lot of that. It appears after I cut out the shape so I'd agree with Peegoo on that one. I usually fill it with epoxy and haven't has any problems.

 

[tomasz]

What you may want to do, is clean up that endblock area a bit more out and glue in another end block with perpendicular grain. This will stop the crack from potentially spreading, give you some area with no fractions for the end pin.

 

[JohnnyThul]

Hi guys,

Thank you all for you contributions, much appreciated! I think, I will just watch the body for the next 2 weeks and see, if there will be any movement or if the superglue may crack.

Honestly right now I am a little too devastated to think about cutting the body apart or do a major repair, let alone start all over again.

I hope it will be the case as others have mentioned, that it is just a crack, non structural, which can be filled and all is good then. Fingers crossed.

Best regards and merry Xmas everyone!

Jonas