Really this could have been included in the last post, but it was getting long and I wanted pictures of my own work above the cut.(edit: here is part 2, a year later.) So here are the first progress shots of my balsa wood violin. Right now I’ve got the foam block marked up and ready to cut out.
So, you say, “I’m not a professional boat builder, where do I get a 3″ thick block of 360x210mm foam??? Well you’re in luck, Lowes sells this blue Dow brand insulating wall foam in a 4×8′ sheet – enough for roughly 9 blocks of violin sized foam. Cut out four 1/2″ slabs of the stuff and glue them together with some 3M upholstery spray adhesive, contact cement, or use some 5 minute set epoxy:
Make sure you peel off the plastic on both sides. Cutting through that later would be a bitch. Plus it’ll peel apart later while you’re cutting it. Two slabs is 30mm thick, which is standard height of a violin rib. The highest point on the top and bottom is about 15mm, which is the height of a single slab. Roughly 90% of the top and bottom slabs will be removed by the time I’m done, with most of the middle two untouched.
Measure out your dimensions and label accordingly (see violin dimensions from last post):
And then sketch out your violin’s outline. I used a thick, stiff leather belt I wore on my trip to South America to draw the radius curves. Hand drew the C-Rib curves (several times). Once you have your outline you can cut it to shape, and then begin sanding down the top. I highly recommend a hot wire foam cutter, which can be assembled from scrap lumber and an old guitar (or violin!) high E string. I should warn you though, DANGER: if you build one of these foam cutters, it involves electricity and exposed wires, which will surely shock, harm, cut and probably kill you. But it’s what I use and most hobbyists use so you’re going to have to roll with those risks. Here’s a link to one (I’m not responsible if you use this information and hurt/kill yourself/others and/or burn down your house building it) link to hot wire foam cutter. Use common sense when building unsafe crap like that and make sure your will is up to date.
Here’s my violin outline. I’m sure it will be modified further by the time I get it cut out.