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Forms Ribs Corner

Ethan's Viola Progress Photos

The article below documents the process of building a viola, step by step. Each step listed links to a photo illustrating that part of the process.

The Form

  1. The pattern—an early Stradivari violin, enlarged to viola size I use a photograph, covered with clear packing tape to make templates that I don't use a lot. That's also more accurate, since fewer intermediate steps are involved.
  2. Wood for splitting out blocks It's carefully cut on the tablesaw to have the right height. These blocks are Adirondak (red) spruce. Cremonese makers used either spruce (the Amati and Guarneri families) or willow (Stradivari).
  3. Marking the corners from the template They're carefully traced from the template, but the marks are just guidelines--ultimately I do what my eyes tell me is right.
  4. Shaping the corners Cremonese makers weren't too careful about squareness, but the lines of their work were always precise. It's more important to look at the corners and compare them against each other than to follow the template marks. I do this against a bright window so I can see only the outline without any confusing details.
  5. Blocks shaped, ready for the ribs At this point, since the blocks were glued on while the form was resting on a flat surface, one side (the top) is in one plane. That's the reference for the plane of the ribs from this point on.

The Ribs

  1. Scraping the first side of the ribs A rectangular cabinet scraper is used, sharpened with a 45-degree edge to knife-like sharpness. Then the edge is turned very gently, to make a tiny hook along the whole edge that does the cutting. The first step is to flatten one side of the ribs to a finished surface.
  2. Marking the rib thickness This tool is a copy of Stradivari's own, which I saw in a museum in Cremona. It's primarily for marking the graduations of tops and backs, but also works well for other jobs, like this one. By turning the nut under the rib, the distance between the nut head and the point/scratcher is adjusted to the thickness required for whatever is being worked on.
  3. Close-up of the marking The scratches it leaves are quite deep. I need to plane and scrape the wood until the scratches are gone. Then the thickness will be correct, just over 1.1mm at this point.
  4. Planing the ribs to thickness The ribs are planed until just a trace of the scratches are left.
  5. The toothed blade of the plane The teeth in the blade prevent the curls of the wood from tearing out.
  6. Scratches from marking; tooth marks from the toothed plane Sometimes the makers of 300 years ago didn't scrape out all their marks, and you can see tooth marks in the wood--especially inside the instrument.
  7. The ribs, scraped smooth and to thickness A sharp scraper makes only shavings--not dust!
  8. Planing the ribs to width I do them all at once, so they're all the same. First one edge is flattened, then the bundle is flipped over and planed to the final width.
  9. Ribs cut to length; ready to bend It's important to organize them so that the figure is going in the right direction all around the violin. Different makers did this differently.
  10. Ribs marked with their block numbers This way there aren't any mistakes or surprises!
  11. Bending the c-bouts; violinmaker's view A thin metal strap pushes the rib securely against the bending iron, preventing bumps and cracks. The iron is quite hot, and just a bit of dampness on the wood helps the heat carry through it quickly.
  12. Ribs bent; ready to glue to the blocks Precise bending isn't necessary, but the ribs should press themselves tightly against the mold when they're in place, so a bit of underbending is better than overbending.
  13. A selection of potential clamping blocks for holding the ribs against the blocks I just throw them in a box after I make new ones, and after a while the ones I need are always in the mess somewhere.
  14. The c-bouts glued and clamped in place Pushing the rib into the c-bout presses it firmly aganst the form, assuring the right shape is established.
  15. Mitering the ends of the c-bout ribs The c-bout ribs are mitered to a feathered end. The ribs from the upper and lower bouts pass over this joint, so all that's seen from the outside is the flat end of the ribs of the upper and lower bouts.
  16. Gluing the remaining ribs onto the blocks Finally the last ribs are glued around the form.
  17. Spruce linings slit out from a larger strip I do this with a knife and straightedge. The linings are cut from bad guitar tops that were used as packing material in one of my wood orders! They were already cut carefully almost to what I needed, and they were free.
  18. Soaking the linings Unlike the ribs, the linings bend easiest if they're completely wet all the way through.
  19. Linings, ready to glue The linings have been bent just as the ribs were, on a hot bending iron.
  20. Inletting the linings For strength, the c-bout linings are cut into the blocks.
  21. Gluing the linings All of the linings are glued inside the ribs at the same time, using clothespins as clamps.
  22. Resmoothing the ribs After the linings are glued in, the outside of the ribset can be quite bumpy, and need to be rescraped.
  23. Leveling the ribset The last thing done to the ribset is to plane the surfaces where the top and back will be glued.

Roughing Out the Back and Top

  1. Flattening the wood for the back I clamp it between a bench dog and my vise dog (a "dog" is a metal finger sticking up that's used as a stop for the work), and use cello posts underneath to prevent it from rocking. Almost all the planing is done across the piece, not with the grain. That's faster, and leaves less of a mess. This piece is already flattened, and scraped smooth.
  2. Aligning for outlining It's very important when the outline is traced from the ribs that nothing moves!
  3. Tracing the outline A pen and a washer mark the outline of the plates 2.3mm from the outside of the ribs, all around.
  4. Finishing the drawing of the outline The washer traces around the corners, but in this area the exact shape of the corners must be drawn in. I do it only roughly, allowing room for adjusting everything by eye when I finally shape the corners. It's one thing to just follow a line; another to make things look like they should, so in the end, I'll do what looks good, not what the lines indicate.
  5. Sawing the outline I don't use too many power tools, but the bandsaw is very handy for this. I stay outside the line I've drawn--the outline will be finished carefully with files later. Notice the safety glasses--I put them in the picture as a reminder that there's no work available for blind violin makers. Anytime there's a risk, I'm sure to be wearing them!
  6. Marking preliminary edge thickness Usually I work in stages, homing in gradually on what I want. Here's an example: using a purfling cutter (just a knife with a guide next to it to keep it running a set distance from an edge) I set the initial thickness of the edge. I start a bit thick for the initial gouging of the arch, and then will remark the final edge when I'm ready to finish the edge to its final thickness.
  7. Gouging to the mark Relatively quickly I gouge down to the mark I made, and then work more on the arch.
  8. Starting the arch Without too much thought, at the start I just remove a lot of the wood that's between me and the finished back.
  9. Developing the arch Under all that wood, there's a viola back! After the gouging, I move to a large fingerplane to smooth out the gouge marks and start finding the arch I want. At this point I'm thinking about the final shape of the arch, and playing with the form to get something I like, but there's still a long way to go.
  10. Initial shaping completed Now I have the outlines sawn roughly, and the arches roughly shaped. It's time to move towards something more precise. The next thing I'll do is file the outlines precisely to the finished shapes so I can finish the edge thicknesses, inlay the purfling, and get serious about finishing the arches.

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