Joining the violin plates
So to the task of joining the violin plates from the bookmatched back and belly sets. First I squared up the beautiful maple blanks and planed the two edges together to ensure a good fit. This was so much easier to do compared with the cello as the pieces of wood are so much smaller/lighter and the join quite short. I heated the pieces gently with the air gun and then glued them together with a rubbed joint which worked really well first time.
Next I planed the underside surface flat before tracing the outline from the ribs and using a washer to give the external dimension including 2.5mm overhang.
I cut out both belly and backs on the bandsaw leaving a bit of waste to be cleaned up after shaping the outside profile.
This was so quick I ran the same process for the belly.
Carving the outside profile
Next I created a set of templates for both back and belly based on the profile curves published by Sergei Muratov (the same source I used for the cellos). I drew these up in solvespace and then stuck the full size printed drawings to a piece of perspex, cut out on the band saw and then finished on the vertical oscillating sander. I finished by spraying these with a bright paint – different colours for front and back so they didn’t get mixed up.
Then to carving starting with a 3/4″ no 5 sweep chisel to get the rough shape.
I cut a 10 mm wide platform at the edge with the router using the same attachment I made for the cello work.
These were cut at the finished edge thicknesses of 3.7 mm (back) and 4 mm (belly) and make it much easier to start the gouge cuts.
Then I moved onto using thumb planes.
Here I am getting pretty close to the final profile.
I tack assembled the back and belly to the sides to cut the side overhangs down to final size – 2.75mm except for the c-bouts at 3mm. Started with the knife and finished with files with a piece of waste of the correct thickness taped to the middle of the file.
Also cut the corner shapes with a knife.
Next job is to cut the purfling groove so I made up a simple holding jig for the body first.
Then I made up a laminate 1.4mm thick for the purfling of 0.3mm black (ebonised pear), 0.8mm white (sycamore) and another 0.3mm black. I sliced this up on the bandsaw into strips about 2.5mm wide.
Then I marked the purfling groove on the front and back with special gauge set in 4mm from the edge and deepened these faint marks with a scalpel lubricated with dry soap and carefully carved out the groove with a 1mm chisel.
Next I carefully fitted the purfling using the bending iron taking special care with the corners and glued up with hot glue.
Then trimmed back with a chisel when dry and gouged the channel round the edge about 1mm deep before fairing everything in with scrapers and checking the final arching.
There is a slight blemish in the maple on the back. I was hoping I would get through it with arching but there is a tiny thin bit left and I would rather keep the proper arching than keep on scraping away – it looks like bark but it can’t be as it was not visible before carving. Should dissappear when the back is coloured anyway.
I started by marking out the thickness profile contours and then drilled on the bench press to a few millimeters thicker than this to make the rough thicknessing quick and safe.
Then I roughed out with a large gouge.
Now I have to build a caliper/nail tool for marking the finished thickness before plate tuning.
And it works really well – I have made it big enough so I can do a cello with it.
Nearly down to the initial thicknesses before plate tuning.