Wednesday, 11 September 2013

Violin Diary-4. Ribs

I left off, in the previous Violin Diary post with the "C" ribs almost complete. This post, which includes a video again, will show you how the "C" ribs are stuck to the blocks, the ribs reduced and cut to the correct width and the upper and lower blocks reduced. See youTube video:

On the previous occasion I had struggled to perfectly bend the "C" ribs. I therefore had to make some small adjustments to the bending of the "C" bout ribs before proceeding. It seems that with renewed concentration and energy, bending the ribs correctly wasn't too difficult. With the minor adjustments complete, the "C" ribs were now ready to be glued to the blocks.

Gluing "C" ribs
The glue that is used in instrument making is a strong animal hide based glue. I'm normally a nervous wreck when using this glue as it dries very quickly meaning that there is only about a minute to complete the operation before the glue becomes too solid to work with. Gluing the ribs to the blocks is a fairly straight forward operation. The main consideration is to ensure to stick the ribs to the blocks and not the mould (remember that the mould is a temporary frame/scaffold that is removed later on). Glue is applied to the block and rib. The ribs are then temporarily clamped while the glue dries fully (normally 1 day). I managed to do this with relative easy, minus the nervous shaking, as can be seen in the video.

Making ribs
The next step is to reduce the ribs to the correct dimensions. Violin ribs are made from Maple wood and can be bought in roughly the desired shape and size as can be seen in the photo below.

There is some effort required to get the ribs to the correct thickness (approx. 1.1-1.2 mm) and width (approx. 33 mm). This is mostly done with a small plane. To my great surprise, I found that this operation was not as difficult as I remember it being the previous time. I was able to reduce the thickness of each rib fairly quickly and managed to reduce the width to the correct width without an assistance. The remaining ribs are now ready to be cut and stuck on to the mould.

Reducing top / bottom blocks
In order to stick the ribs to the blocks, it is necessary to first reduce the top and bottom blocks to fit the contour of the model. This is done by drawing the outline of the model using a stencil. Thereafter the excess wood needs to be removed using a knife. While making my first violin, I had found this step very tiring and tedious. I had blisters to show for it too. This time I had carvers gloves and improved technique and confidence. I found it really easy this time. The hardest part is to ensure that the newly carved surface is perfectly perpendicular to ensure that the ribs can be stuck flush to the block. This took a little time and patience, but went smoothly.

By the end of the day, this was the result.

Next time I'll reduce the outer corner blocks, cut the ribs to the desired length, bend them and stick them to the blocks.

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