the Back Continued - the Bracing

The trickiest element to installing bracing on the back is to account for the radius of the back. Remember even a flat top guitar isn't really flat. Well the curvature is much more pronounced on the back. Ken has cut the correct radius on the bracing for you but you have to be carelful to "shim" the back to the same radius before glue up. Ken uses a method of placing index cards in a row underneath the curve of the bracing and gradually stacking the cards to maintain consistent contact with the bracing. Its hard to explain but maybe the pictures will clarify. I only had a small stack of index cards - not nearly enough - but I did have a couple of decks of playing cards. So what the heck, they should work fine. Before any glue up you need to shape the bracing with a gentle arc that thins down to 1/8" at the edge. Same as on the top it took a skill saw, a wood rasp and some sand paper and I was in business.

I worked on this througout the day gluing up two braces at a time.I saved the little curved section that I cut of each end of each piece and used them as cauls for clamping. And the deep throat cam clamps are ideal for this.

Here you can see where I shimmed the back with the stack of playing cards.

Here you can see where I used the end cut off as a caul to create a flat surface for glue up. I would never be able to get the correct tension on a curved surface.

After glue up you can finish shaping the bracing. A nice rounded top is called for. Because you need to get to 1/8" I protected the rosewood with some tape. This shaping was all chisel and sandpaper work. And I used a popsickle stick as a hieght gauge to get to 1/8".

Sorry for all the bad photos. The final product. You can see a litle reveal betweed the work board and the back because the radius doesn't allow the back to sit flat.