Spiling veneers

Laying strips down and butting the edges together is easier said than done. Despite the fact that the first strip started life with straight edges, by the time it has been bent round the double curvature of the mould form it takes on what is known as ‘edge set’; what was a straight line now describes an arc. When the next piece of straightedged veneer is placed alongside, the edges won’t meet and you will find a gap either in the centre or at the ends depending which side of the first veneer you are working to.

When a straight plank is bent to a curve its shape alters such that the next straight edge won’t butt cleanly against it

This is where novices will often try to force the veneer edges together to fill the gap which, while not impossible, will usually result in a bulge developing somewhere along the veneer. To counter this problem the new veneer must be made to fit by cutting its edge to meet the previously-laid veneer: this process is known as spiling.

The easy way to determine this arc is to slide the two planks together on the form until they touch either in the centre or at the ends. Take a drawing compass with a pencil and adjust to the widest point of the gap then, with the compass point resting against the first plank, scribe the line the length of the plank. This shows what must be removed and can be roughly cut with a band saw then planed to shape. The process is repeated for each piece of veneer.