Bracing, backs and rosettes

After bending the sides, the next step is to install the neck block and tail block.  These blocks provide a lot of structural strength when the guitar body is all together.  The neck block also houses the joint that keeps the neck connected to the body.

Next, we install kerfed linings around the edges of the sides.  These linings provide additional surface area for gluing the soundboard and back. 

We also install vertical braces on the side.  These braces guard against the risk that, if someone drops the guitar and cracks the side, the crack could travel up the sides farther.  The braces are designed to stop the crack from travelling very far, so that it's easier to repair.

Next, we use the molds to trace the outline onto the back and side materials, then cut them to rough shape on the bandsaw.

The back gets a thin strip of cross-grained mahogany up the seam to guard against cracks at the joint.  I glue these on with a "go-bar deck," which consists of fiberglass rods bent between a piece of plywood up top and the back plate down below.

 

All of the gluing is done with the back plate on a 15' radius dish, which is the shape that the back will ultimately have.

I glued up the rest of the braces on the back as well using the same process, but didn't take pictures. 

Now, I'll make the rosette and install it on the soundboard.  I'm making this rosette from a piece of very figured mahogany I had lying around.  I use a special rosette cutting tool on the drill press, which has a couple blades that spin around and cut out the material in a circle.  I also cut the channel for the rosette in the soundboard.

I coat the soundboard in the rosette area with shellac to protect the wood from the cyanoacrylate (Super Glue) that I'll use to glue in the rosette.  The cyanoacrylate will stain the wood an ugly color if unprotected.

I cut the rosette channel big enough that I can also inlay very fine strips of black/white/black purfling material that I bought from a luthier supply house.  I squish the purfling into the channel on both edges of the wood rosette, and cut it to length with a sharp chisel.

 Next, I run the soundboard through the wide belt sander and sand the rosette flush with the rest of the soundboard. 

Somewhere in there, I cut out the soundhole, but apparently I didn't take pictures of that.