The blocks are the very first pieces to be made that will remain a part of the finished violin. They are pieces of willow (Amati and other makers would have used spruce) that are cut along the grain, planed square and glued to the mould in a particular orientation according to the grain direction. Bonus points for spotting the block that is wrongly oriented:
After the blocks are glued on, the template is used to lay out the shape of the corners:
We’ll follow this particular corner block thru the process. First to be carved away is the inside curve of the C-bout. The outside curve remains uncarved at this point, so a nice rib miter can be made later, and also to give support while clamping the C-bout rib.
Now the c-bout ribs can be bent to fit the mould (more about bending ribs soon…) and glued to the blocks. Glue is applied only to the surfaces where the rib meets the willow block. The ribs are clamped in place with counter-forms made to correspond to the curves of the ribs. Thanks to Minneapolis violinmaker Bill Scott for this clamping method using radiator hose clamps:
Next the outside curves of the corner blocks can be carved. The ends of the c-bout ribs are carved in a way that continues the line drawn on by the template. This will allow for that neat, tight rib miter:
Now the ribs of the upper and lower bouts can be bent. The next photo finally illustrates the rib-bending process a little better. Please forgive the chronology-challenged post. Like i said, i’m only human.
Anyway, the ribs are strips of maple (often from the same piece of wood as the back plate) that are thinned to a consistent 1mm.
The ribs are dampened with water and held against a hot iron. The heat from the iron drives the moisture thru the wood until it becomes flexible, essentially steam-bending the wood. If the wood is bent at just the right time in this heating, it is pliable enough to bend to shape without cracking, and will retain its shape once it cools.
The metal strap is used to further prevent the wood from cracking, especially in the tightest of the bends.
If everything goes well, the wood holds its shape remarkably well…
…so well that some alternative methods of construction forego the wooden mould altogether, bending the ribs freehand to a desired shape. This is also how guitar sides are often bent.
Once the bending is finalized, the rest of the ribs can be glued similarly to the c-bouts. Tailor-cut counter-forms are again used to clamp everything in place.
The ribs, being only 1mm thick, don’t provide much in the way of a gluing surface to attach the top and back plates, and so we bend and install 2mm-thick strips of willow, called “linings” along the inside of the entire outline.
The c-bout linings are inserted into mortises cut into the blocks to prevent them from pulling away from the ribs should the glue deteriorate. If this were to happen, it could cause a nasty buzzing while playing, which could only be remedied by taking the instrument back apart. This system also adds strength to allow for the flexing of the ribs while the mould is removed later on.
The linings are glued with homemade clamps made from clothespins and bike inner-tube:
Once the linings are trimmed down flush to the rib surface, and the miters of the rib corners are cut to their proper length (and angle), the rib structure is more or less complete.
All that remains is to ensure that the rib structure sits flat on a flat surface. A flat stone, machined metal or flat glass plate are used to check that the assembly doesn’t have any high points or dips. This ensures that the eventual glue seam between the ribs and plates will have as little undue stress as possible.