Cracked top

[Jack Lord]

I wasn't careful about the humidity in my shop and the guitar I'm building just developed a crack in the top.  It's unfinished except for several coats of shellac on the top.  Anything I can do to rescue it?  Can I force glue in?  Is so, Titebond or hide?  Is it best to do it while still dry and spread?  Any suggestions will be appreciated.

[Chris Sisson]

Hmm, I'd try to treat it as if I were gluing the two halves of the top together.  That will work if there isn't too much shrinkage, otherwise treat it like any other top crack by shaving a sliver of wood from the cut-offs and force it in.

[Jack Lord]

Thanks for your help Chris.  I'll see if the sliver is necessary after I humidify it.

[Paul Verticchio]

Humidify it until it closes. That's imperative.

Then, squeeze in some Titebond as if repairing a crack in a 'finished/completed' instrument. Lots of info on how to do that in the most basic of repair guides.

If you're a builder (obviously) you MUST pay mercurial attention to the Rh in your workshop. There are many discussions in the forum's archives which address the technicalities involved.

Better luck with your future builds :)

[Jack Lord]

Thanks Paul - I have it humidifing now. This is the seventh guitar I've built and have always been meticulous about humidity, but got careless this time.  Wish me luck!

[Paul Verticchio]

Oh man, Jack. If I listed all my "Oooooops's" over the years, they'd have to build a library to contain all the volumes. :) And they're all titled "It was my fault because......".

Sounds like your back on track with the guitar :)  I bet you'll have the very best of luck from here on out.

Take care :)

[Jack Lord]

Thanks for your kind words Paul ... misery loves company.

[Jack Lord]

The crack is pretty much closed now Paul, just a hairline.  I only have a few coats of shellac on the top.  What is better, Titebond or hot hide glue?  If Titebond, it seems to me Titebond III would be better for this application than the original stuff.  It seems like it was a surface crack, I felt nothing inside and a thin piece of paper would not go through.  I want to make sure I don't stain the top.

[Paul Breen]

The least visible glue repair to a crack such as yours would be hot hide. Easier clean up too.

[Jack Lord]

Thanks Paul.  Should I let it dry completely before cleaning the top off?

[Ned Knepp]

Jack,

 You can let it dry it you want and then lightly scrape it off. I usually wait until it gels to a Jello consistency then rub it off with my hand and a damp, not wet, cloth. That's not very long since it starts to gel as soon as it cools even a little bit.

On a crack that long you should warm the top pretty good before you start with the glue so you have time to work it into the crack before it gels. One of the things I like about HHG for a repair like this is that I don't worry too much about smearing it around too much. Having the top seal with shellac really helps with this.

[Jack Lord]

Thanks Ned.  I was wondering about heating the top first to help it penetrate; not too much though so I don't dry it out again.  Now that it's re-humidified, the crack is just a hairline.

[Jack Lord]