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What having a good Viola will let you do with a Violin
A Word for Word description of removing the top from an instrument to repair cracks and reassemble
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Ray Wells
Ottawa Canada
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April 16, 2013 - 8:19 pm
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Having a serviceable CVA-500 14" Viola to continue learning to play a stringed instrument allowed me to be a bit adventurous with my damaged violin and try to affect some repairs. This is the story of the repairs.

Repair of my C1918 Nippon Trade Violin

I received this violin as a gift from a friend who was leaving our seniors residence. It had no bridge and its strings were old and tarnished and the bow had about 1/3 of the hair it should have. As well, there were several cracks in the top that ran to the end block end of the violin. The purfling is painted on so all cracks ran right to the edge of the top. Also there were places at the edges where the top was not attached to the side.  Initialy I used hide glue to close the cracks and seams as best I could from the outside and stabilized the instrument to see how it sounded when I put a set of inexpensive strings on it. It sounded fine and I began to learn to play. Still beginning!

I next determined that I preferred the more mellow sound of a viola and bought an inexpensive one and switched my learning efforts to it and I decided I could risk sacrificing the old violin on the alter of experience and attempt a comprehensive repair of the cracks. I have experience repairing sensitive electronic test equipment and know well enough to think things through and plan every action ahead of time.               I watched many Youtube videos in preparation.

The first tools I bought were a soundpost setting tool because that would need to be done at the end of it all and an artist's pallet knife recommended in videos to separate the top.  A thin blade is required to get into the top seam but the knife should not be ridgid enough to allow prying against any wood. I removed strings, bridge, pegs and rests and began the disassembly. The fine pallet knife blade got into one of the open seams and I worked my way around the top seam WITHOUT prying on any wood, just working the knife edge on the level into the thin brittle hide glue that kept the top on. This took about half an hour and the top came off without incident.

Carefully I put the sound post away for later and examined the open fiddle. I brushed out all the dust and noticed where the label had been scratched off, probably around the time of WWII. I removed the old hide glue from my repair of the top cracks and proceeded to repair them with the advantage of being able to clamp them closed after reglueing. Each cleaned crack was brushed with the warm water used to heat the hide glue then the hide glue was applied and the crack closed and clamped. The hide glue is said to “bloom” when it penetrates the pores of the wood and a little warm water helps to open up the pores and facilitate entry of the glue so that as the glue sets, there is a bond between the wood parts that have glue between and inside them.There were 4 cracks to fix with one occureing through my own mishandling of the top while repairing. The thin top will not bear the unsupported weight of the clamps and you must always support their weight. I made a crack by lifting the wood rather than the clamps. But only once! After the cracks were glued shut it was necessary to prevent them reopening.

This involved placing small 1/4” cleats of wood at the start, end and middle of the cracks. These cleats were oriented so that the grain of the cleat was at right angles to the grain of the top. Of course they are glued and clamped. Not having access to 20yr old seasoned spruce, I used the light wooden sticks from Chapman icecream treats for the cleat materiel. Hence I am tempted to name the instrument the Chapman Fiddle.                                                                                                                           With all the cracks closed and cleated it was time to put the top back on. I have only 8 trigger operated clamps and we need about 36 clamps to completely surround the outside of the instrument. I try to be frugal so I decided to build my own spool clamps. I bought 3 pieces of threaded rod 36”x3/8” to be cut into 4” lengths for 36 clamp shafts. I bought a 4'x1” hardwood dowell to be cut into 3/4” thick disks. Also required were washers that fit the rod and serve as a bearing surface for the locknut at one end of the shaft under the bottom disc and similarly a washer allowed bearing force under the wingnut on top of the upper disc. As a cushioning material on the faces of the wooden spools that would touch the instruments, I used preformed, self adhesive felt discs intended for the legs of chairs. These discs have the advantage of being inexpensive and when you drill them to fit the threaded rod, the material sort of moves out of the way but still holds the rod in tension and you can spin the spool into a holding position on the wood of the violin where it provides compression even before you tighten down the wingnuts to proper pressure. So over a couple of hours my son and I built 28 spool clamps and the ingredients cost about $60.

BEFORE applying any glue, TEST FIT ALL THE CLAMPS you intend to use to practice setting them up quickly and to preposition the spools on the clamp shaft. Also if you plan to use any trigger operated clamps plan to position them either side of the neck and at the “end pin” end of the instrument. They can create more pressure and there are actual blocks of wood at these points that provide important gluing surfaces to hold the violin together. If you have enough trigger operated clamps, the four corner blocks of the D and C bouts are the next most important gluing surfaces which also deserve these stronger clamps. Practice more than once getting all the clamps in the right place in the order that you planned. It is a good idea before you glue to lay out the clamps in your planned order of use on your work surface.

When you actually glue the top to the rest of the fiddle you need to work purposefully and quickly but DO NOT RUSH. I worked on the kitchen counter next to the stove where I would heat the hide glue.

I used 'Old Brown Glue' which needs to be heated to between 100 and 140 degrees F. The plastic bottle has a tapered top which should loosely close the top as the bottle sits in a few inches of water in a saucepan until the water comes to a rolling boil for a few minutes. Then turn down the stove element and remove the tapered top.

I used a small artists paintbrush to brush all surfaces to be glued with a swipe of hot water from the boiling water heating the glue. I then used the paintbrush to dip into the glue bottle and painted glue first onto the block of wood at the neck end of the violin, under the fingerboard. Then I painted glue along the edge of the violin taking care to be generous with glue on the corner blocks of the C bout and then around to the top of the End Block continuing past the end, I painted glue on the edges and again gave particular attention to the Corner Blocks of the D bout. Immediately following I painted the edge of the top following the same pattern around the top.

With glue applied to both parts I slide the top onto the bottom, carefully fitting the neck end of the top under the finger board ensuring the slot in the top fit properly into its junction with the neck. Trigger clamps were applied either side of the neck and also either side of the end block. Remember that the clamps must only put pressure on the edges of the top.Trigger Clamps were applied next to the four corner blocks. The trigger clamps were closed enough to secure the top in proper place. Now the remaining spool clamps were applied about 2 at a time, shifting between left and right sides of the violin to maintain pressure balance until the violin was surounded by spool clamps. With all spool clamps in position, increase clamping pressure by tightening the wing nuts (which should all be on top). Snug up the trigger clams at the ends. We are not demonstrating how strong our grip is, we are closing the top of a delicate box. Set the violin and clamps away to cure for 12-24 hours. After removing the various clamps  examine all seams for excess glue which can be cleaned up with a warm damp rag.

Next step is to lightly attach the strings and bridge and this is a good time to add a Wittner type tailpiece with integrated string adjusters. Now use your soundpost adjusting tool to place the soundpost. I had to retrieve the dropped soundpost about 12 times before I worked out how to set the post. Remember though that there is probably a mark where the sharp end of an adjustment tool was previously pressed into the soundpost to set it initially and this probably the best place for you to grab the post yourself. As well you might notice a difference in colour in the wood of the bottom of the violin where the Sound Post had previously stood. Look also for how the top and bottom of the sound post are beveled to match the slant of the top and bottom of the violin. Go with it. Once the post is in you can tune your violin slowly up to pitch and show the world what a good luthier you are.

Ray

PS   The bow that came with this violin has been rehaired but looks like it could be a better bow if it was recambered so that is a task for later.

PSS   In the process of getting my CVA-500 14" Viola I first got an identical instrument which shortly after it arrived had the center back seam open up. I glued this seam shut and the instrument functions but this is the next candidate for having the top removed and proper repairs made.

Ray Wells Violin/Viola Mechanic in Training.

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Violaman
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May 6, 2013 - 3:34 am
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It's amazing what you can do when you feel free to experiment or just to try something new.

Thanks for the post Ray. :-)

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Donald
Rødvig Stevns, Danmark
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May 7, 2013 - 4:52 am
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There is another reason why the Japanese label may have been removed, the Japanese used to have a reputation for making cheap mass-produced articles. A similar phenomenon now exists with regards to the assumed reputation of items made in China, Korea, Taiwan or India.

I do not think German labels would be removed because of WW2.

I wonder where else besides Japan violins or violas with painted purfling (sic) have been made ? How widespread is it ?

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Violaman
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July 8, 2013 - 3:32 am
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Really hard to know these things. Don't you think that on some occasions the Chinese do the same thing Donald?

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Donald
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July 12, 2013 - 4:44 am
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If some Chinese do not paint on purfling already, after reading this maybe now some of them will start doing it.

 

I am intrigued as to whether with an instrument painted a colour such as black, white, blue, red, (instead of a transparent varnish), you can still work out if there is purfling under the paint ?

 

I have never seen the tool used for purfling, could be some kind of knife or it could be a very small chisel, I do not know.

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Violaman
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July 31, 2013 - 2:01 am
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First of all you use a purfling knife that has a spacer for the outer edge and two small sharp spaced knives. Then you use a curved purfling chisel to dig out the wood between the to gashes you made with the first tool. :-)

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Barry Nelson
Nashville,Tennessee
July 31, 2013 - 5:00 am
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Great video Pierre !!

Bach : As the greatest expert and judge of harmony, he liked best to play the viola, with appropriate loudness and softness

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Donald
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July 31, 2013 - 6:00 am
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That clears something up for me. I mistakenly assumed there were going to be two grooves made with two strips of inlay, but it is in actually one groove with an inlay of a three piece sandwich strip.

 

I have come across two explanations of the purpose of purfling.

 

1. To stop cracks spreading along the grain of the top (plate ?) of the instrument.

2. To allow the top (plate ?) to vibrate / resonate better - because the purfling thins the plate just where it is glued to the ribs, making the joint area more flexible.

 

I do not know if either of these is incorrect or if both are correct.

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Barry Nelson
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July 31, 2013 - 4:21 pm
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I think only the thickness of the plate and the grain would effect how it resonates, I know that the purfling is meant to stop cracks but its also decorative .

Bach : As the greatest expert and judge of harmony, he liked best to play the viola, with appropriate loudness and softness

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