Violin Forum/Message Board

[magicfingers]

How does one go about bending the liner tip to the curve of the head??? Is there a process or some kind of chemical that will soften bone so it will fit the radius of the curve??? Thanks, Lonnie...

[Jack H.]

There are a few ways to do it.
I have a wooden block with a groove cut into it to fit the head of the bow and part of the shaft.
the tip plate is thinned with a file but left wide. with a triangular file make small grooves on the sides of the tip plate so the thread will have a place to rest and not slide all over. make a lot of them, but only on the sides. fit the tip plate, put the bow tip into the special block and with rehairing thread, wrap it around the tip and block ( I also have small grooves filed into the block) starting at the tip of the tip plate working towards the back. the tip will bend to fit the head. Please apply cyanoacrylate glue before wraping with the thread.
Another method is to use a metal jig with a clmp and a curved plate that bends the tip as clamping force is applied.
There is also another metal jig that can be purchased that bends the tip plate and then it is applied at a later time, but it is hard to get the precise curve..., when I use this method I generally let the tip soak in hot water ( or what I like to call H2OT) and it is less prone to dreaking, but the problem os th eliner comes off and has to be reglued which is a hassle.

I mostly use the second method, but what ever method you use you have to be careful and ensuer that the tip is on straight and tight up against the tip!!!!! WIth crazy glue there is not a lot of time for adjustments!!!!!!!

Good Luck
Pleas epardon any typos, I just finished a 10 hr day...
Jack Havivi
Havivi Violins
Israel

[Ed]

Hi, I bend bone tips in a wood block setup. The curve of the wood blocks matches (or slightly exceeds) the curvature of the bow face you are trying to prepare the bone for. The bone is soaked in hot water mixed with washing soda for about 1 hour. Then it is put in the clamping blocks and clamped overnight. The next day, when it is taken out of the blocks, it is in a bent condition and can then be glued on to the bow without tension. Most of the time it works very well. Every so often, I get a tip that does not want to bend the first time. So I try it again. Here's a pic of the bending block arrangment. You have to be careful not to allow the part of the bone that covers the point of the tip to be under pressure when in the clamps, other wise it will break easily. I dont know what the composition of washing soda is, or where to get it (other than the supplier I have used in the past).

[magicfingers]

Thanks guys for the replies....


Ed, what is the brand of washing soda that you use??? Is this the same as bakeing soda???? Also, what is the amounts of the mixture and about what temp is the water???? Thanks, Lonnie...

[Ed]

I just looked up "washing soda" on Google - here's a definition:
washing soda
n : a sodium salt of carbonic acid; used in making soap powders
and glass and paper [syn: sodium carbonate, sal soda,
soda ash, soda]


It is "sodium carbonate". Baking soda is sodium bicarbonate.
I just saw that you can buy Arm&hammer washing soda on Amazon. But, it might also be available in grocery stores in the soap section.
Re mixing it up - I get really hot water (close to boiling) and add it to the soda in a 35mm film canister. I think it's close to a concentrated solution.

[magicfingers]

Thanks Ed, I'll give it a try and see if it works for me..Lonnie..