Soundboard (Pt. 1)
After completing the sides, my next step is to build the guitar’s soundboard. This guitar is going to have an Adirondack Red Spruce soundboard.
Trees almost never grow wide enough to make a guitar top from a single piece of wood. That is particularly true of Red Spruce trees, which are small than most spruces. So the first procedure is to cleanly join the two halves of the soundboard. The pieces that will become the top of the guitar came from my supplier with fairly rough surfaces. The gluing edges for the center seam are trued on a jointer. The two halves are then glued together using the wprlboard in the picture below. At the top of the picture you may be able to see that there are pairs of wooden wedges. These wedges slide together to put clamping pressure on the center seam.
After the glue dries. the soundboard is sanded to a thickness of about 0.110″ on this sander. The sander has a rotating drum covered with an abrasive paper.
Now it is time to make the soundhole rosette. For this guitar, my customer has specified a ring of abalone with black-white-black lines on either side of it. After determining exactly where the soundhole will be, I use a small router to cut a channel about 1.5mm deep into the soundboard for the rosette.
First the black-white-black lines are glued into the channel along with a strip of teflon that is the same width as the abalone. After the glue dries, the lines are scraped just about flush with the soundboard using a sharp metal scraper blade.
Next, the teflon strip is removed and the abalone is carefully glued in place. Abalone is supplied in thin, straight pieces and it has to be carefully broken to go into the channel. When done right, none of the breaks are visible and it looks like the abalone was cut in a circle.
After the glue dries, the entire rosette is scraped and sanded flush with the top and the soundhole is cut out.
Bracing the soundboard is the next process.