|Dan Erlewine offers this tip:
The soundhole clamps can reach places that I can't, for sure! I attach numerous gadgets to either the top or bottom of the clamp to help with repairs deep in the belly of the guitar.
I use the .008" gauged saw held in the fixture shown and attached to the clamp. I'll use it to loosen and remove glue between braces and the top (or back) that I can't reach with my hand.
First I remove the saw blade from its back or handle, and trim it to the shape I like.
Then I remove the bottom foot from the clamp and replace it with a 5/16-18 machine bolt which holds the saw blade (or any number of thin pallette knives, sandpaper, etc).
Conveniently, the curved frame of the clamp doubles as a handle!
I needed to heat up a crack in a top that someone (not me!) glued and ended up with less than a flush surface on the outside.
I slide the clamp inside the guitar with a hot block of aluminum attached. I clamp that to the trouble spot and the hot metal warms and loosens the glue so I can realign the crack.