This is page 3 of a pictorial essay of a build. The guitar will be an all Koa 12 Fret W body when it's finished. I've got a new video camera. There's a video of voicing the top on this page, as well as a side bending video on page 1. Click on the images for a bigger view.
The last braces I glue in are around the soundhole, and the finger braces. The center picture is the braces, before any voicing. Click the link below the pictures for a short voicing video. The picture on the right is the completed braces. I'll do a final clean up, and final voicing after the top is installed. I install the top before the back so I can do this. The resonance of a free plate will be different than after it's glued to the rims. The braces are all Adirondack Spruce, except the upper transverse brace. It's Sitka with Rosewood in the center. It's job is to keep the neck block from rotating inward, causing the need for a neck reset. The neck block will be right against it. The bridge plate is Osage Orange.
I used to install tops and backs as soon as they were braced based on information I had read. Now instead of installing them immediately I let them sit in my climate controlled shop so the moisture introduced to the wood by the glue has a chance to dry out. While the top is acclimating, I'll work on other things, including the back.
I made a fancy jig to put the 15 foot radius on the back braces with my router table, but I've found it's just as easy, and alot more simple to mark them, trim to the mark with a hand plane, and finish the radius in a radius dish. I can't pass up the opportunity for another shot of my go bar deck. Yep, hot hide glue is used.
After they're installed the back braces are shaped. They're made kinda triangular, and taper toward the ends. I install a softwood, cross grain center strip last. Some do it first, and cut out for the braces. I see no advantage with either order. I use masking tape to get the length right for a perfect fit. The braces are Mahogany. The center strip is Redwood. The picture on the right is the finished back, pending a final cleanup. I'll also add a label later.
Now it's time to install the top. I notch the upper transverse brace, and the upper ends of the "X" into the linings. I mark them, and then cut the notches with a foredom tool, and router base.
It's time to install the top. I add 10% salt to my hot hide glue mix for this. It lowers the gelling point ~10 degrees so I'll have a little extra time to get everything together and clamped. I warm the top, and rims some with a heat gun. I normally use cauls to keep the go bars from damaging the top, but this top is Koa, a hardwood. The go bars won't dent it.
Brackett Instruments
Handmade acoustic guitars
Grover NC
It's all about the tone!!!
704-937-2499
