The outline and measurements
  1. For the mould, use a 12 mm thick, 400 mm tall and 250 mm wide piece of wood. It is important that the wood is as stable as possible, so multi-layered plywood or battenboard are preferred.
  2. After you have cut it to the right dimensions, you need to transfer the outline.
  3. First, draw a centerline on the wood, then align the template with it.
  4. Now you need to drill two holes, about 8 cm in from top and bottom of the template, on the centerline, drilling through the template itself as well as the wood. For this, a drill press is the best. See the Templates chapter for the exact location of the points.
  5. Then get two wooden pegs, matching the diameter of the drill bit. Or you can use the drill bits themselves.
  6. Securing the template in perfect alignment with the centerline in this way, scribe a line along its contour, flip the template on the other side and repeat. Repeat also on the other side of the mould, making sure the orientation of the template is correct.
  7. Now you need to transfer the lines as in Fig. 1, all measurements are in millimeters. The cornerblock recesses are drawn as follows: 1. Draw the "a" line, 2. Using a compass, from point x1, measure 26 mm and create the point x2 on the C bout, 3. from x2, draw the "b" line connecting it back to the "a" line.
  8. Repeat on all remaining corners. Repeat for the other side as well.
  9. It is also a good idea to mark the top and bottom side of the mould so that you always know which side is facing you. Also, add an inscription on the top of the mould about the name and author of the source violin you are interpreting.

Cutting out the mould
  1. After you have marked out those lines, you can proceed to cut out the actual mould. The best tool for this is the band saw, which will make it easy for you to achieve the perfectly perpendicular cuts. If you are cutting the mould by hand, make sure you stay well off the line and that you are not undercutting into the line on the bottom side.
  2. Use a file to finish the contour.
  3. For the clamp openings "c1-c8", a press drill again is the best tool. Predrill all the holes with a 3 mm bit. Then, using a 25 mm drill bit, to avoid splitting, start a hole on the top, drilling about 1/3 in, then flip the mould and finish.
  4. The four "e1-e4" holes should now be predrilled with a 2 mm bit. Four screws will be later used here to elevate the mould above the workbench surface a bit when attaching the blocks.

    You can see the finished mould in Fig. 2.
  5. Dry soap should now be applied on the perpendicular side walls of the mould, excepting the areas the blocks will be glued to. This prevents accidental gluing of the ribs to the mould, should you spill some glue where it does not belong.
  6. The areas where the blocks should stick - the longer sides of the recesses - should be glue sized with thin hide glue.

The blocks
  1. Cut spruce blocks to the following sizes: Top "A": 32 x 50 x 22 mm, Bottom "B": 34 x 46 x 20 mm, Upper corners "C, D": 33 x 25 x 28 mm, Lower corners "E, F": 33 x 25 x 28 mm. The grain should run perpendicular to the bottom plane on which they "sit", allowing for easy, precise cutting {from top to bottom} later on.
  2. At the bottom side of the mould, screw in four screws into the predrilled holes so that the mould gets lifted evenly by approximately 9 mm. Make sure that all four screws make contact with your flat workbench and that no rocking is present.
  3. Fit the blocks in the mortices in the mould. The gluing surfaces are the thick red lines in Fig. 3 It is important that these surfaces are in perfect contact with the mould. The top and bottom "A, B" blocks should have a slight gap at the sides allowing them to be inserted easily. Make sure the annual rings are directed away from the mould as in Fig. 3.

    With most violins, the height of the ribs decreases gradually along the length of the body. Therefore, in the finished violin, the bottom block may be 32 mm tall, whereas the top block may be 30 mm in height. This, of course, affects the upper and lower cornerblocks as well. For Messiah, the final heights in the finished rib structure is as follows: A 30 mm, B 32 mm, C 30.5 mm, D 30.5 mm, E 31.5mm, F 31.5 mm.
  4. With these numbers in mind, if necessary, trim the blocks to their final heights leaving them about 2 mm taller.
  5. Glue the blocks to the mould using medium thickness hide glue. Apply the glue to the longer side of each mortice only. Remember, you will have to break the blocks off the mould when the ribs are finished, so avoid applying too much glue. Hold in position with your hands for about 30 seconds. Let dry overnight.
  6. Once the glue is completely dry, sand the blocks down on both sides, bringing their height to about 1 mm above the final numbers. For this, use a long belt of sanding paper clamped down on both ends to your workbench or glued onto a flat /ie. 6-8 mm thick glass/ plate. Later on you will finalize the heights of the ribs using this method again, but this time with the ribs already glued on.
  7. Take the template, realign it with the mould, mark the contour on all the blocks with a pencil or a scribe. Mark the true center of the violin on the top and bottom blocks. See the red lines in Fig. 4.
  8. Flip the mould over and repeat the marking on the other side.

Comment by
2014-12-08 01:07:52
The direction of the grain of the blocks is crucial, to make it easier when you shape the blocks to the rib outline. Make sure the grain (front to back) runs in such a way that when you gouge to the line the wood will not split in the wrong direction, causing you to undercut the line at the back of the block.
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Comment by
2018-04-24 14:11:15
Comment by
2015-11-15 12:37:51
what size is the mould?the same as the half template?
Comment by
2015-11-21 00:02:42
[Comment deleted]
Comment by
2016-09-20 23:30:17
Is both sides of can be angled upwards the mold?
Comment by Vojtech Blahout
2016-09-22 08:23:16
If you refer to the tapering of the ribs, yes, you should apply it to both sides.
Comment by
2018-09-28 19:11:11
Taper both sides of the ribs? So the front and back have independent 1mm tapers that sum to 2mm taper overall?
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Comment by
2018-10-25 16:03:59
it may cause bending on face plate when clamping face plate to rips !??
Comment by
2018-11-16 20:38:33
2mm in total and Stradivari did it on the top side and upper bouts only. And yes it means that the plate will have to bend a little.
Comment by
2017-06-11 05:48:51
The first step to transfer the lines is "1. Draw the "a" line". From where do I start making this line? From what reference do I use?
Comment by
2017-06-11 12:07:02
Hello, thank you for pointing that out. For some reason, some of the numbers were not showing up in the browser, but they were in Inkscape. Fixed now. VB
Comment by
2017-06-12 01:39:24
Thanks for fast answering, but I still don't know where to start to draw the "a" line in the corner blocks. In the upper and botton blocks I can measure the Width from the upper and botton points of the violin, and the lenght from its centerline. But what reference in the violin do I use to mark in the corner blocks?
Comment by
2017-06-12 23:45:51
Provided you have the violin outline transferred onto the mould block, you just measure the 124 mm from the very bottom (on the centerline) and make a line going all the way to the outline. The A line is 9 mm long. I hope this helps. Let me know if you need further clarification.
Comment by
2017-06-13 00:37:14
Thank you very much.
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Comment by
2018-08-24 07:37:05
If I was to print the mould from here.... directly would it be accurate?
Is it important that the blocks are made of spurce or can they be made of pine or something similar?
Comment by
2018-08-24 07:37:11
If I was to print the mould from here.... directly would it be accurate?
Is it important that the blocks are made of spurce or can they be made of pine or something similar?
Comment by
2018-09-03 10:40:35
It should be accurate given you print it out to the correct dimensions. The blocks are usually made of spruce but other woods can be used. It all depends on the piece of wood you are about to use. It should be both firm and light. Cheap violins sometimes don`t have blocks at all.