Pickguard cupping on an 81' Guild F30

[eliya]

Hi everyone!

The top of my Guild F30 is cupped where the pickguard is, along with a small crack near the fingerboard extension. To me this seems like the classic pickguard shrinkage and cupping, and Frank has two, very thorough guides to fixing this problem (this one and that one). However, I want to make sure that this is in fact pickguard shrinkage and that the prying and re-gluing of the pickguard with water-based glue is the right fix. I'm attaching pictures of what it looks like.

The first picture shows the cupping halfway across the length of the pickguard, and you can see that the cupping starts almost from the edge of the top. The second picture shows the cupping close to the fretboard extension. Last one is of the crack.

The finish looks like lacquer, but I have no idea if the pickguard is celluloid or not. I'm assuming it doesn't really matter, because you can see the shrinkage in the third picture. The only thing I'm concerned about is that the cupping starts all the way from the edge of the top (first picture).

Also, do you guys have a preferred wood for cauls? From the pictures Frank posted it looks like he's using two 3/4" pieces of plywood glued together.

Thank you!

[eliya]

I never posted here again, but the repair went really well, and the pickguard is quite flat.

Now it's time to repair the crack and I'm working on the right cleat to put there. Originally I was thinking of a narrow diamond shaped cleat, but seeing Frank's repair here and here, I'm thinking of going with a piece that is about an inch wide, and going all the way to the brace under the fingerboard. Would that be enough reinforcement? It should be noted that the crack on this guitar isn't as bad as the two cases Frank shows (see pictures in the original post).

Thanks again!

-Eliya

[Greg Mirken]

That sounds fine. It's OK to be on the safe side here and go a little bigger than you would in a more active part of the soundboard.