I only build the floor and ceiling in defined curvatures. This makes them both more attractive in sound and more stable and resistant to the constant stress of professional use. I'm thinking of expansion and tensile stress due to heat etc.

By defined I mean that all gluing and sanding work is done in curved shapes. The following dimensions for the radii:

• Ceiling curvature 25'
• Bottom curvature 15' (Feet; 1 Feet = 12 Inch = 2,54x12=30,48cm)

After the beams have been sanded to match the curvature, they are glued to the ceiling form with skin glue.

Once the beams are all glued, they are carved and optimized for sound. I hold the soundboard carefully between my index finger and thumb the soundboard close to my ear and tap carefully on the wood. If it sounds too high, the soundboard is still too stiff - it must become more flexible.

I do this in two steps. First I carve the ends of the beams and then I remove thickness from the sides of the beams with the small luthier's plane.

The bottom was joined and here sanded to thickness.

A channel for the decorative strip is milled with the router. Here I am gluing it in at this moment.

If the decorative strip is plastered with the scraper, glue the seam stiffener to the finished inner side

The floor beams, which are also sanded, are glued.