Now before I glue the braces down on to the back of the top plate I have to shape them to the desired radius. As I mentioned in the last post I am using a 25′ radius.
The radius dish I made will be used for the glue-up but it will also be used for putting the radius onto the braces. I have seen some make a special jig just for putting a curve on the braces but I like the idea of using the radius dish. So in the next step I tack some 120 grit sandpaper down on to the inside of the dish where the brace will lay and start sanding by moving the brace back and forth.
Sanding the correct radius into the x-brace
Checking the fit. I will also do the same for the other braces excluding the braces in the upper bout.
Before I glue the x-braces down I need to notch them so the other 6 tonal braces can tuck in under them. The braces in the upper section stay flat.
I pre-shaped the tonal braces so I could find my position to mark and notch out on the x-braces. I also marked my end points and maximum depth for the scalloping on the braces. I used a French curve template and a thin strip of hard maple to trace curves on to the braces.
I pre-shaped the x-braces before gluing them down. You can see my end point and maximum depth pencil marks. It seems many luthiers shape the braces after gluing them down but many luthier supply shops sell pre-shaped brace kits so I decided to shaped them before gluing to avoid any nasty slips I am prone to making.
All the braces pre-shaped and ready to go.
A close up of the scalloped braces.
Gluing down the x-brace with my makeshift go-bar. The go-bar is a clamping system many luthiers use to get clamp pressure down on top of the piece. In my case I didn’t actually make one I just used 1.4 meter x 10mm dowels in between the braces and my workshop ceiling. I even put rubber booties on them cause I get rain leaking in when it pours.