These are the arch offsets I used for the side-to-side arch for the back of this guitar.
The back graft is being notched to an interference fit for the back braces with a razor saw.
The notches are carefully shaved away with a slim chisel.
Pictured here are the necessary notches for the back of the Sal's flamenco.
The first back brace is being glued. The orientation of clamps are suited so the brace is glued upright, because cam clamps pulls the object toward its jaw as the lever is applied.
The slight glue squeeze-out must be clean out with a chisel. More care must be taken, because the back is now arched, so as to avoid digging the ends of the chisel into the back. A slim chisel does help a little, but still.
Here, the X-brace with the up-notch is first glued. I have fitted the other X-brace with it, but glue is not applied. this ensures the perfect accomplishment of the desired angle of the X.
The brace is glued to its planned position.
Due to the arches of the back braces, a flexible backing slat is stick on to the opposite side, while each back brace is clamp during gluing operation. I use a brown hardboard, commonly found in art stores.
Now the other X is glued.
The final back brace being glued. Time to call it a day.
