Sign in to follow this  
colorado john

F. Contal Cello button/back repair

Recommended Posts

I just picked up an old french cello stamped F.Contal at an estate sale. It's a nice old cello, pretty common mid-19th century Mirecourt work but well made, not cheaply/roughly carved. When I inspected it before the auction I noticed the neck had come loose from the block and was just attached by the button, which had a wedge patch. Later during the viewing someone knocked it over and broke the neck completely off, snapping the button away from the back. I was heartbroken to see this new damage but bought the cello anyway; it went cheap owing to the newly broken neck.

Where the button broke away I can see the internal patch/wedge from a previous button repair/neck reset, placed to support the button repair.

I consider myself a competent amateur repairer and was wondering if some of the more experienced members could give me some advice. Should I attempt my first neck reset and button repair on such a nice old instrument? I've worked on some German and JTL factory fiddles and feel confident on something of that value but this cello is a step above them. How should I go about dealing with the previous button repair internal patch/wedge? Remove it or leave it in place and just carve it down?

Thanks.

Share this post


Link to post
Share on other sites

This cello seems like a good candidate for a 'clavette' repair.

Cut a mortice into (apx 5mm) the block and carefully fit a piece of maple that's carefully selected to match the existing neck foot into the mortice. What you have now is a shelf. One side to glue the button on, the other side to set the neck to. The 'shelf (clavette) is glued into the top block.

Correct fitting of the clavette is the important factor. Make sure that the clavette is at the correct angle so that when you glue the button to it the button fits back where it came from without gaps. Make the clavette about 5-8mm thick. (appx the thickness of the button)

You can make the clavette extra long and trim after you've set the neck.

Good luck

Oded Kishony

Share this post


Link to post
Share on other sites

Obed:

Thanks for you advice. This cello has had a clavette repair before I've discovered. There is a "shelf" type patch behind the button that is still partially in place. Should I remove this old shelf and replace it with a new one or is there a way to salvage the old shelf by further patching over it or maybe just regluing the button to it? The neck mortice seems to still be fairly tight, although I won't know until I've taken the button off of the heel and reattached it to the back and stabilized the crack starting to go down the back from it. (fear of damaging the the wood splinters of the broken button keep me from trying to force the neck back test it)

I suspect I'm going to have to remove the old clavette because I don't think it would be strong enough with a glue repair. I'd to do the simplest and least invasive repair possible though. Your opinion?

Share this post


Link to post
Share on other sites

Obed:

Thanks for you advice. This cello has had a clavette repair before I've discovered. There is a "shelf" type patch behind the button that is still partially in place. Should I remove this old shelf and replace it with a new one or is there a way to salvage the old shelf by further patching over it or maybe just regluing the button to it? The neck mortice seems to still be fairly tight, although I won't know until I've taken the button off of the heel and reattached it to the back and stabilized the crack starting to go down the back from it. (fear of damaging the the wood splinters of the broken button keep me from trying to force the neck back test it)

I suspect I'm going to have to remove the old clavette because I don't think it would be strong enough with a glue repair. I'd like to do the simplest and least invasive repair possible though. Your opinion?

Share this post


Link to post
Share on other sites

John:

What's the condition of the block that's holding the clavette? If the 'shelf' is broken off is it because the block is cracked?

Why don't you email me privately I don't check this board that often.

Oded K.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.