Copyright 2005-2006 www.jjsviolins.com
 
Crack Repairs With Cast » Back

Pic 1 -

This violin was brought in as a players violin, handed down from Great Grandad, poorly repaired earlier. The teacher is very hard to satisfy and liked the sound of the violin, so it was decided that to spend the money to restore it to an instrument that could be counted on was worth the effort. Final cost, just under $2000 with new bridge, post and pegs, all cracks redone and buttoned up with cleats and a finger patch.

The first step was to remove the top and pour a cast, done by gluing the top to a flat board, building a dam and protecting the top with a thin latex sheet. This is discussed in previous entries and can be found in the archives of the SCAVM. This cast had to be reshaped inward (scraped) because the cracks were glued sunken previously and also had to be filled and reshaped in areas using a two part epoxy filler (Bondo, you can use these new glues in the cast, they have their place, but they should never be used on the violin itself.).




Pic 2 -

This crack presented three problems, a through patch that you can see above the corner that was expanded and unsightly, dirt that was rubbed into a poorly glued crack and some sort of plastic glue (epoxy probably) that was used throughout (four cracks total) to glue the top pieces together. Several hours were spent chipping this glue out piece by piece and a bath of oxolic acid removed the dirt stains that I was not able to remove by water alone.



Pic 3 -

This picture is interesting only in that it shows that the wing crack and the lower bout crack closest to the bass bar must have been accessible from the inside to clean up, but that the same glue was used. The same repairman must have had two opportunities to repair this violin, once with the top off, and once with the top on (who can know?). It is too common that newer adhesives are thought to be stronger. Hide glue, used properly is the strongest bond to be found. I often see cracks that are along a center seam, the seam is not open, but the soft wood alongside it has failed instead. I have heard it explained that you can think of it as gluing two pieces of bread together with cream cheese (new adhesives) or honey (hide glue). Does that help? Hide glue soaks into both sides of a joint and produces a protein bond. New adhesives fill a gap between two sides of a joint. Hide glue requires a perfect joint, but is reversable and far superior.

Pic 4 -


This picture has a little shock value to it, but I wanted to show how the cast under the separated pieces aids in bringing a repair job back together. The extra work of making a proper platform to assist you in gluing a crack minimizes the opportunities for that crack to be improperly placed while your glue is drying.

Pic 5 -


There is nothing left to chance here, the pieces of wood glued to the edge assure that the clamps providing inward pressure will not damage the soft edges of the violin. Glue is applied to the crack and the top is massaged into the cast as the brass clamps are softly tightened, then downward pressure is applied carefully to insure that the top is firmly seated in the cast. Finally, a little more pressure is applied to the gluing area while the clamps on the perimeter assure that the top cannot buckle under the tension of the closing (brass) clamps. Still with me? A few cleats have already been glued in place to reinforce the work that is already finished and the clamp in the soundpost area is attempting to push out some of the indentation left by the bridge feet.

Pic 6 -

This is a shot of the fingerboard crack before I delivered the job. There was a little more retouch work done, but this is pretty good as it is. I will wait for the new varnish to shrink a little bit and will be able to cover up the crack a little more yet as I see the fiddle for maintenance.

Pic 7 -

Job completed. The violin sounded good before and sounded fantastic after. This was a satisfying, if frustrating job for me and my customers were happy. The world is a little better for having this job done. Thank you .