Preparing the back part II

Next up is to prepare the joints for glueing. The hide glue used in instrument making does't fill any gaps so it is very important to get the two pieces to be jointed to match very well. This is done by lighting the boards from one side and looking for any gaps. I had already jointed the boards before taking any photos so I simulated the effect by inserting a 0.05 mm feeler gauge between the boards at one end. The light is more or less in the center of the back lengthwise so the gap between the boards on the centre photo is roughly half of that. Once the feeler gauge is taken away there is only very little light coming between the two halves of the back.