Friday, 3 February 2012

I did some more work on the 'viotti' model. Purfling, fluting and arching.

 As I decided to use the same method as for the viola (fluting up to the edge), I made a test piece for the viotti as well. This time I made top and bottom corners exactly the same width (6,9 mm). I was told by to professional makers that this is typical Cremonese, it has to do with the way of setting the purfling marker and the proportion of corner-bee sting.
 This is the top corner on the test piece with the purfling glued in.
 The fluting is now down to the final depth.
 The edge work is done on the test piece.
 The outline is drawn from the rib structure on to the flattened plates.
 Most of the fluting is done before the purfling. I leave about 0,5 mm extra thickness to do the final trimming of the purfling.
 The same thing is done on the front. I try to do quiet a lot of arching as well, I just feel like it comes naturally from the fluting. Let the curves flow!

 Detail of fluting up to the edge. The flames on the back are quiet obvious even in the fluting!
 Before going too far with the arching on the front, It's good to draw the f-holes on as there position determines the final shape of the arching. After reading the article from Hans Pluhar in the 'trade secrets' from the Strad magazine about placing the eyes of the f'holes in relation to the outside line of the ribs, I decided to apply that on my violin (as it can be a real struggle to locate the f-holes in the right place and make them look good at the same time). In the article, the f-holes are located from the inside of the plate once it's hollowed, but I thought, why not try the same method from the outside, I just need to mark the the outside line of the ribs on the outside of the plate which is very easy (2,5 mm from the edge = overhang). And it seems to work very well! On the photo, you can see the marks of the divider near the bottom corner.

 The Bottom hole is traced firste, the top hole is then located in relation to that.
 The purfling is done. Before cutting the channel, I thinned the original purfling which was 1,25 mm wide to 1,1 mm (same as the 'Viotti'). That way, the black of the purfling is slightly thinner which makes it look more subtle.
Detail of left top corner. (front)
 Detail of right bottom corner (back).
 Then, I finish the fluting to depth. The thickness of th plates in the deepest point of the fluting is 3mm in the bouts and 3,2 in the C-bouts.
 Detail of fluting and purfling  on the back. It was quiet difficult to cut the fluting along the grain with the strong flames. I found it helped a lot to wet the surface a little to slice trough with a frech razor sharp gouge.
 The finished fluting.
 Now the arching can be finished off. In that proces, I keep drawing the f-holes on.
Using low-angled light, is is easier to look for bumps and asymmetry.

Detail of C-bout and f-hole.