Finishing the corners
- Remove the four screws from the mould again.
- Plane down the heights of all the ribs on both sides, leaving them just a little proud (.5 mm) of the blocks. When planing, follow the outline of the ribs with your block plane to get a smooth cut.
- Measure the span of the upper "A-B" and lower "C-D" corners and compare it to the original violin. If you have got the original plate outline printed out you can also now try to align the ribs over it and check this way how close you are to the original. See the red plate outline in Fig. 1.
The final ends should ideally be where the feathered C bouts end.
- Determine where the final tips should be and mark them at the top of the ribs. See the red dashed lines in Fig. 1.
- Using your razor sharp knife, trim the upper and lower ribs` protruding ends so that they extend beyond the previously made marks by about 1 mm. See Fig. 1. Be very careful not to chip the ends - when you are getting near the end of the cut, stop and finish the cut from the opposite direction.
- If the final ends don't coincide with the feathering, see the paragraph below for possible solutions.
- Make the ends of the ribs flush with the feathering using an abrasive paper block. Make sure the tips are at right angles to your flat surface (workbench).
- Use the sanding pager of your flat surface to make the ribs level with the blocks, on both sides. You should still be left with the rib height a little (.5 mm) higher than the final heights.
In case you're a little off
If the tips of your ribs are still too wide and you have already reached the feathering, you can still reduce their width but the thickness of the C bouts at their feathered ends will also have to be reduced, because at the very ends of the corners, the thickness must still remain that of the ribs, which is about 1.1 mm, not more. In
Fig. 2. you see this done for the lower right corner
"D". The red dashed lines denote the material removed.
If, on the other hand, the feathering is inset too much and it doesn't reach your projected tips, you will need to shorten the tips further to reach that feathering even if it means the resulting violin will be a little narrower at the corners.