restorersmind

The button is the semi-circular tab at the upper back. It is an extension of the back wood and helps to anchor the neck into the body of the instrument. As one might imagine, the neck joint/back button area must be able to withstand a lot of tension. When this area suffers damage or deterioration (frequently associated with the neck coming loose), the button may crack on either side and along the purfling. Or it may break away completely:

Ouch! This button has actually gone altogether missing and will require a replacement – a related operation perhaps worthy of another post.

Let’s look at this instrument. It’s a 19th century Flemish violin. The button is cracked at the sides and along the purfling. This instrument also had an issue with the center joint, but we can ignore that at the moment.

First the back is accessed by removing the neck, top and interior block. Old glue and dirt are removed from the broken button area and the button is glued to the back as cleanly and evenly as possible. Then the area is to be reinforced with an interior doubling of healthy wood. In this case, maple for the back.

I’ve made a simple mold of the area with a red plastic-like dental compound. The button/back fits perfectly in the mold, which will be of utmost importance as I work the damaged wood down to a thickness of .05 mm at its thinnest. Here, the patch bed is cut down deep enough to reveal the purfling peeking through from the exterior.

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The patch bed is concave, like a bathtub, and will be scraped to a clean, uniform surface. I will then shape a new piece of wood to to fit perfectly in the cavity I’ve created. As the fit approaches a finished state, small wooden cleats assure the correct positioning of the new wood. Btw the center joint issue has been corrected and reinforced with long tabs of willow.

Here the new patch wood is glued in.

And here it is after it’s been cut down flush with the rest of the back.

I’ve chosen a piece of European maple that is similar in character. While most of it won’t be seen, I do want the grain lines and medullary rays to be as close to the original as possible. This will be important later.

The instrument is reassembled: ribs returned to the back, a new upper block installed, the top replaced and the neck reset. This instrument required a new neck graft as well, evident in the next photo.

The neck heel and the doubled button will be shaped and revarnished together. I will save my retouch skills for the face of the button and allow my grain matching to help blend the new patch wood into the old. I do not try to make this particular repair invisible, although I do appreciate an end result that is skillfully subtle. I differ from some of my colleagues in this matter. In my opinion, an expert can always tell when the neck has been reset, or a button previously broken. Personally, I would always prefer to see the reinforcement, and see that it was done well rather than wonder if it was done at all.

Finally, button (and center joint) restoration, before and after.