Cutting the upper and lower bout blocks
  1. Remove the four screws from the mould.
  2. Remove the excess height of the ribs leaving them just a little proud of the blocks. For that a small sharp block plane can be used. While planing, try to follow the shape of the rib to avoid splitting the ends. Repeat on both sides.
  3. Use sanding paper on a flat surface to make the ribs flush with the blocks but don't remove any material from the blocks. Now the mould should be sitting on your flat surface without rocking.
  4. As with the C ribs blocks {in the previous article}, using a suitable gouge, pare away the wood on the upper and lower corner blocks to the contour line depicted in red in Fig. 1.

    The difference here is the need to create a feathering at both ends of each C rib, see how the red line cuts into the rib.
  5. Shorten the tips of the ribs to a distance where the final tips will be, in our example, the finished tips will protrude about 2 mm from the tips of the template. Observe the template outline and determine where it will naturally cross into the tip of the rib, creating the feathering. If you have the original or its photograph, try to determine where the tips of the ribs end there and approximate. See the red dashed lines for suggested tips in our example in Fig. 1.

    When cutting, make sure the tips end up at right angles to the bottom plane. For this, you can use the sanding paper glued to a square block of wood.
  6. Using a suitable, sharp gouge, create the feathering, cutting across grain from top to bottom.
  7. Make the rest of the outline in the corner blocks flow naturally into the newly created feathering.
  8. You can finish the surfaces with sanding paper on a stick making everything very fluent and smooth.

    Again, the transition between the block and the mould must be as smooth as possible. Use your fingers to check for that.

    Check often that the newly created walls are perfectly perpendicular to the workbench.
  9. Cut the top and bottom blocks, again to the red line as depicted in Fig. 1. Finish using sanding paper on a square block of wood.
  10. Reapply soap where it might have gotten sanded off.

See Fig. 2 for how everything should look like when finished.

Category: Ribs