Making an invisible neck graft

A procedure that takes a little longer than the standard method, but results in an almost undetectable fitting

TRADE SECRETS

Makers reveal their special techniques

Alterations to the neckset on an instrument can be historically seen as the first step in the modernisation of Baroque instruments. The first modern necks may have come from the workshop of the Mantegazza brothers at the end of the 18th century. Since then, different ways of grafting a new neck have been developed, and this has become a standard procedure in violin shops. Nowadays the process is mostly used to replace necks that are worn out, narrow or too thin.

I have always found it strange that when starting a neck graft, some restorers deliberately use wood that does not match the original. This contradicts all other practices in the restoration of stringed instruments, where the commonly accepted rule is ‘the less visible the better’. I am personally fascinated by neck grafts that are hard to detect, especially if a restorer has used deeply flamed wood. However, I have seen some grafts that are hardly visible from the side, but when viewed from the front can be spotted by the artificial, painted-on dirt covering the joint on the pegbox edge.

I recently had to perform a neck graft on a very old violin that still retained its original neck. Because the wood was only lightly flamed, I took it as a challenge to make the graft as invisible as possible. And because the violin had a transparent, light orange varnish, I knew the only way to hide the joint seen from the front would be to put some varnish on it. Then I came up with the idea to hide the joint inside. Here is how I did it.

The triangular-side surface is drawn on the pegbox

ALL PHOTOS ANDREAS PREUSS

1 I cut off the neck in the usual way to prepare the graft, and draw on the location of the graft using China marker. The end of its triangular-side surface will be exactly in the second peghole (this is the D-string peghole on violins, and G-string peghole for violas and cellos).

On a usual graft, the mortise for the new neck cuts through the top of the pegbox (i.e. its upper edge). Using this alternative method, that material will be preserved.

The mortise for the graft has been cut

The mortise seen from below

2 First I pre-cut the joint lines with a small saw. Then I remove the material between both lines with a small chisel (2a). The problem with using a chisel to cut from the pegbox end towards the head is that it runs against the grain, pulling up the fibres. So, as far as possible, I try to cut the upper joint from the side, using a long knife. Finally I cut everything clean. Picture 2b shows the surface where the glue will be applied.

Test wedge for the fitting

3 For a clean fitting it is necessary to make a test wedge that fits into the mortise. This step is necessary to make the upper glue joint as clean as possible.

The test wedge seen from the front

4 The upper glue joint runs out to the outer edge of the upper saddle. If it is exactly on this line, it will be invisible when seen from the front.

Fitting the test wedge

5 Fitting the test wedge is a little more time-consuming than for a normal graft, but worth the effort. It ensures that only minimal adjustments will be necessary to get to a perfect fit when its dimensions are transferred to the graft. Later there will be no varnish touch-up necessary, except for the staining of the inside of the pegbox.

I begin by fitting the triangular-side surfaces and the underside, as with a normal graft. When both the triangular surfaces are fitted, it does not mean that the diagonal inside-joint surfaces are fitted too. For this, I slowly plane down the triangular-side surfaces of the graft until the sloped upper side touches the diagonal line.

The fitted neck

6 In the final stage, the angle of the sloped surface must be micro-adjusted. When the test wedge fits well, its dimensions are transferred to the neck graft block.

How the invisible graft looks after touch-up

7 With the dimensions of the wedge transferred, the graft still needs to be refitted before gluing. After reshaping the graft and touch-up, the grafted neck is difficult to detect.

Unlike a traditional graft, the invisible graft cannot be used to widen a narrow pegbox. The result is best if the graft material is either old wood or has been slightly stained throughout, either using the baking and/ or the ammonia methods.