Official Luthiers Forum!

Hi Gang,
I have a friend who owns an inexpensive ($200) 12 string acoustic guitar which has a crack in the soundboard at the side of the fretboard at the soundhole. She was keeping it in a poorly humidified room (we live in AZ) so I removed the strings and kept it in my guitar room at %50 for a few months and the full-thickness crack is now together again, but obviously, more needs to be done. There is a crack in at least the finish all the way up to the neck block along the side of the fretboard. I can't see if it goes through the entire soundboard all the way up. My thought is that the poor humidification and the stress of the 12 strings has lead to the problem. If so, it needs to be supported between the neck block and the soundhole under the fingerboard. I want to do this in a way that won't compromise sound. Can I glue another block (like enlarging the neck block) under the topwood that is covered by the fingerboard? Should I glue it to the neck block or try to make it independent (more like a beefy post) between the back and topwood? Can I mend the crack (which no longer has a gap) with superglue once the support repair is done?
Any different or additional suggestions?
Thanks for the help! Beth

Yep, add a block which you can glue to the side of the head block. Try to keep the block as small as possible while still having sufficient glue surface area to attach to the top and support the crack. It should not affect the tone or volume of the guitar as this is a pretty dead area anyway.

The crack should also be glued and the Titebond or HHG you use for attaching the block will work on the crack. The best way I have found to get the glue to penetrate a tight crack is to squirt some on the finished surface and rub it around with your thumb using some pressure. Applying some finger-tip pressure to the underneath side of the crack will open the top of the crack slightly and allow more glue penetration.

Thanks so much, Barry! I think I can do that. Have a great day. Beth