Shaping Stones

Chapter House, Santa Maria de Ovila

Work Portfolio: W. Oskar Kempf

Many of the portal arches disappeared over the years. Some where too damaged to be restored. About 40 % needed to be newly carved to complete the needed count. We choose Texas lime stone, for it's properties matched the original stone best. To allow me a competitive estimate for the carving of stones verses precast replacements, I decided to speed up the carving process with some homemade machines.

1. We cut blocks to carving size

2. The blocks where aligned on a round table, precisely on the outline of the arch curve. The first and last stone, I marked with the template of the carved shape.

3. With a self constructed radius cutting machine, I began to cut the shape from the outlines, on 15 stones at once.

4. With our pneumatic chisel, I removed the rest and began to shape the details with a router head

5. To shape the intrados and extrados I used again the radius cutter. The diamond wheel guides the curve.

6. The pneumatic chisel quickly removes the rest, and a router disc shaves the remaining extrusions.

7. The last step is a chiseled finish, and the joint cut, to shape the joint angles. We used again the radius arm to find the center point.

The stones fitting now nicely into the arch curve.