I am going to replace a lot of the purfling on the back I'm making. The model has thin edges, and a thick center strip, and the thin edge combined with short purfling didn't work. When it starts getting thin it looks shabby, even if it is still there. The belly must have had a taller piece of purfling, and it was stuck in the groove within a mm or two, and not .5 mm, and I stayed somewhat further from the purfling when bringing the recurve in, and I may have cut the back a couple tenths of a mm thinner.
The bottom line is: the belly looks ok, but the back needs some TLC.
Cutting the groove back into where it was glued, and may still be glued in is no picnic; but I see no way out. NOt all of it will need to go, but much of it will. I am thinking of making my own purfling. I've thought of doing it with thin strips of wood, that aren't glued together. I've done that, and it works fine. But I think it may work better to glue the strips together in the groove, using fish glue, or casein; and then pulling them out, and re-gluing like normal purfling. The hardest part of loose strips are the corners.
Well, I have work to do.
Ken- did you set the purfling in at least 1.5 mm deep? I have a violin based on a Del Gesu Kreisler 1730 or Kochanski1741, or a 1746 Montagnana. Which one, I don't know, but after examining it looking at the rounded over outer edge, past/over the purfling to where the recurve gradually starts sloping upwards makes me think the trench doesn,t need to be real deep. Just my opinion though. Is there any chance of incorperating the "Ferni" 1736 upper c-bout corner areas into your plan. They don't petrude out as far as other models including what I have. Reason mentioning that is this- while playing faster passages the bow will sometimes catch the upper corner lobe. I'm still waiting for the time when I lose a clump of horse hair, damage a bow or worse. It appears with a corner area built like a Ferni that could be less likely to happen. If I was sure there was still .5mm left to work with, I'd keep going. In another post you mentioned using water to help with the planing. If I can't get dry bar soap to help remedy the planing situation {no water}, I would go the chisel, gouge-disc sand route real slow.
ReplyDeleteThis model, the 1717 Montagnana has what I think they call reverse graduation. The center is thick, and the edges are thin. It makes the long arch very strong, but the plate can flex side to side; not as much pumping up and down. The arch is pretty high, so I don't think there is too much chance of smacking a corner. I'm just going to write about how I fixed it, and how I will do this model the next time. I never heard of using dry bar soap. Is that like using paraffin on the sole?
ReplyDeleteKen
Lets say the plane or chisels/gouge are perfectly tuned/sharp as possible, I will rub the sole, run the blade edge and the surface of the wood with a chunk of bar soap. Coast {blue/green colored} works better than another white colored piece I have. Paraffin may be better. I never owned any. After 3-5 passes I will put some more on if needed. If I remember right, it was Paganini #20 I was having the hair hitting the upper corner. After that happens it rattles me for a second, then makes me wonder" what's up with that"? A few millimeters of more space could be a difference for my playing technique.
DeleteSounds easy enough to try.
Delete