Crack repair

[Masato]

I'm trying to build my #1 guitar now.

After installing binding, I noticed that there is a crack on the spruce soundboad.

It is lower part of the soundboad, near center joint. About 2inch long.

Crack is not very deep, but it seems having dirt in it and looks very bad.

I was very shocked... really...

Crack was there when I noticed, so I have no idea about when and why it happend.

Maybe it is because of low humidity. Roughly always, my room is about 50% humidity conditioned though...

I would like to know how to repair it.

Any advice and suggestions will be greatly appreciated.

BTW I did shellac finish once to avoid chipping and scratch during binding process.

Thank you.

Masato

[tippie53]

you need to be sure it is a crack and not glue sink. Gently see if a piece of paper can go into the joint. Cracks can happen from low RH. I do glue up my tops and braces at 40% RH . If there is a glue sink you can try working some glue into that. If it is a crack you need to put a small cup of water in the guitar and cover the sound hole. when the crack closes work glue into the crack and apply a cleat over the joint inside.

[Masato]

Thanks for your advice.

I'll put your suggestion into practice.