Written by Ray Nichol
Published: February 7, 2015 at 10:13 AM [UTC]
We’ve worked on regluing a centre joint on a cello (without having to remove any of the original wood) and then repairing a few cracks to the top.
Other repairs, in the shop ranged from: installing peg bushings followed by drilling and reaming out new peg holes. You have to glue in an exact tapered dowel into the peg hole then once the glue has dried drill an offset hole for the new peg hole. You cannot use exactly the same location. Ream out the hole into a tapered hole and then shape a new peg. The last step will be to retouch the peg box so that the bushing will blend into the original peg box. Easy (smile).
Now I’m back unto the violin and the stage that I’ve been working on for the past week has been installing the purfling onto the two plates.
Installing the Purfling
Purfling is that black, white, and black border you find around your violin, viola, or cello. It is not only decorative but may help prevent the possibility of a crack, from travelling further up the plate. Purfling is three pieces of wood which have been glued together and then cut into thin strips.
Before the purfling is installed the plates have to be prepared. I will first need to cut the depth, along the edge of the each of the plates, to 4.5mm on the corners and 4.0mm along the rest of the edge. Then a platform that is 10-12 mm wide which is of course level and very smooth is cut into the plates. The purfing will be installed along this platform.
I’ll be using a purfling marker, which consists of two blades (sometimes one) which are set at the width of the purfling and at a distance of 4 mm from the edge of the platform. Even though the purfling marker has two very tiny blades you only want to mark the wood not cut deeply into the wood. Using a scalpel I’ll next, very slowly, cut into the plates to the depth I want for the purfling. If you have ever watched an inch worm walk you will understand that I will have to VERY slowly cut into the plates. One wrong move or if I do not hold the scalpel at 90 degrees to the wood will not only ruin the appearance of the violin but also may create a buzzing sound for the player which would be very hard to find!
The waste wood, from the channel, is now removed. What is important to know is that the purfling marker cannot be used to mark the corners of the plates. The area where everyone looks has to be done by hand and is said to be the DNA of a luthier.
Now comes the fun part because now the purfling has to be heated to 100 degrees in order to bend into the right shape. But heat will also separate the three layers if you hold a fraction too long near the heating iron.
The corners of the purfling needs to be carefully cut so (ideally) there will be no gaps at the joint and all 8 corners need to as close to be identical as possible.
On Friday we were able to visit the Ashmolean Museum, in Oxford and have an up close look at Stradivari’s Messiah and Nicolo Amati’s The Allard! I’ve included a couple of the many photographs, I took so that you all could have a look at the purfling of the two of the greatest violin makers. I especially like to thank the staff of the Ashmolean Museum, particularly,Anne Maria,for allowing our small group access to a small part of their collection.
Next week, my own purfling will be glued, trimmed, and I’ll be profiling the outside of the plates. It is really getting exciting.
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