Band Saw & Back Bracing

I'm thrilled.  The parts came in for my band saw, so I was able to assemble it yesterday.  Everything worked, and so despite being under six feet of water and sitting for several months in a storage shed, it's almost as good as new.  At the instant, I don't have blades for it, but the end is in sight!

If I seem overly expressive, for lutherie work, the biggest and the best band saw you can buy is worth the investment.  Why big?  The impulse is to buy a smaller band saw -- a guitar sized band saw -- but that is a mistake.  Because smaller band saws won't cut the plates for the back and sound board on a guitar.  You need a saw with at least a 10 inch depth of cut, and able to accept a 3/4 inch blade -- at least.  Although I love LMI, and I am always pleased with the quality of their products and their service, it's cheaper and more satisfying to start from scratch on all parts of the guitar.

Beyond that, I have done some work on the back of the guitar.  There is an order of precedence to the back.  One begins, of course, by bringing the bookmarked plates to thickness.  I aim for a thickness between 3/32 or 1/8th inch.  I joint the two plates.  If there is no back strip, that is sufficient, but if there is a backstrip, I like to cut it at the same thickness as the back and glue it up.   You can see it in the photo at right.

The strip itself is maple, and I ran a strip of B/W purfling along either side, just to set it off a bit.  Because it is laminated, and not inlayed, it runs through the entire thickness of the back.  A word of caution, this makes for a more fragile joint, so you will want to handle it carefully, until the reinforcement strip is glued in place.

The next step is the reinforcement strip.  The best way to get the correct grain orientation is to cut a 1 inch wide strip off the bottom of the glued up soundboard.  I used a piece of the redwood scrap, and cut mine from that.  Because I didn't have my bandsaw, I had to cut it on the table saw and so it was cut thick.
   

Once I had glued it in place, I simply planed it down to a better thickness -- again about 1/8 inch.  I glued it in place on the Go-Bar deck, using every go bar I could muster along its length.  You can see the reinforcement strip in the photo at left.  When I had the reinforcement strip in place, I traced the outline of the guitar on it the back, then cut out the rough outline using my jig saw.  Normally I would use my band saw ... see what I mean. 

The next step is the bracing.  I used redwood for the bracing of the back.  I had originally thought I would use the black walnut, but decided against it.  I wanted a lighter bracing, and the redwood seemed to be the right path.

One does the bracing for the back in the same way that one does the bracing for the soundboard.  I used a block plane to cut the rough radius on the bottom of the brace, then sandpaper on the radius dish to finish an exact fit.

I laid out the locations of the braces along the reinforcement strip, and cut through the reinforcement strip with my small X-Acto razor saw at a right angle to reinforcement strip.  Then covering the kerf with the brace, I would mark the thickness of the brace on the reinforcement strip with a sharp X-Acto knife, then cut the second kerf.  I popped out the reinforcement strip with a chisel.   I then glued the braces into the slots on the reinforcement strip.

The top two braces are 3/8th thick by 3/4 inches high, the bottom two braces are 7/16th inches thick and 1/2 inches high.   

When the glue had set, I then carved the braces.  I measured in two and a half inches from the inside edge of the guitar, marked the brace, and cut the scallop using a sharp chisel.  When the scallop was done, I cut the top edge to a peak using my mini-plane.  The final step will be the finish sanding.