Friday, January 29, 2016

Bending Rosewood Sides for Style-00

This week marked the beginning of a new build, the Redwood/Rosewood Dove-00. I started by joining the old growth sinker redwood top. This particular piece of wood is very strong with the grain but a little softer cross grain, I sent it through the thickness sander and took it down to 3mm.
Next, I prepped the Madagascar Rosewood sides for bending. I traced a side template that I designed in Rhino3D and made on the CNC, this gave me my exact size and taper for each side rib. Using this template, I flush trimmed the sides to dimension on the router table. I sent both sides through the thickness sander until they reached a thickness of 2.3mm. I bent the sides using a heating blanket, sheet steel and a bending mold that I designed and build with Rhino3D and CNC. I dampened the rosewood with water and wrapped it in paper towel and foil. I placed a heating blanket on the rib and sandwiched it between two spring steel sheets, placed it on the side bending mold and started the heating process. While applying heat for three minutes, I slowly pressed the center waist clamp down. Next, I bent the lower bout by slowly pulling the spring clamp, repeating the same process for the upper bout. 
I let the side cool down for 30 minutes before I gave it another 3 minutes heating session. I kept it in the mold until it cooled down to room temperature and removed the wood from the bending mold, peeled off the foil and transferred it to the outside mold. I clamped the cauls in place to prevent the wood from springing back helping it retain its new shape. I constructed the neck and tail blocks, trimmed the ends of the ribs flush and glued them in place joining the two sides together giving me the first glimpse of what this guitar will look like soon. 

- Justin Ness