Friday, June 8, 2012

Carving a Jauch Triple Rose

The Andreas Jauch lute in Copenhagen that I am using as a model has a single rose. However, my client is partial to triple roses for large lutes and I agree with him. I don't necessarily copy the rose pattern that is on the original of the lute that I am modelling and I seldom change the design from a single to a triple rose. But a few years ago I measured a lute by Johannes Jauck, a relative of Andreas, in Brusssels no.251. This is its rose. I thought Johannes would approve of the switch.

I recognized that the design was taken from a rose pattern that I had in my collection. I selected the portion that I needed, whited-out the bit that wasn't necessary and drew in the continuation of the little part that I did need. I then photo-copied it to the size I wanted.

I had thinned out the soundboard to 2.0mm over its entire surface. In this photo I have marked off the rose area and I am thinning it down to 1.0mm right in the centre of the triangle that the three roses form.  I allow the area to become gradually thicker as it runs toward the edge: 1.3mm at the edge of the rose triangle and 1.6mm or so at the edge of the belly in this location.

I like to layout the ring border of the rose and cut it before I glue on the rose patterns. I have found that the paper patterns distort a little when the glue dries and this causes problems with centering the rings. The circle cutter is really meant for paper and is not substantial enough to adequately cut into spruce so I use it to score a line that I then deepen with a knife. The little black blocks are thin pieces of ebony tack-glued to the soundboard. I have drilled a very small hole in them, not all the way through, but just enough to secure the point of the tool.  They come off easily with a hot knife when I have finished with them. I spaced the three roses in the same manner as the Brussels Jauck but made them a little larger to correspond to the larger size of the Copenhagen lute and placed them in the same location.

I scored all of the lines of the rose pattern with a small instrument maker's knife and then, working section by section, removed the waste portions. Rather than cutting all the way through the soundboard I used two micro chisels that I had re-shaped to make them suitable for rose carving. One 17th century inventory of a lute maker's shop listed twenty-odd small chisels. Presumably for carving roses.

The chisel on the right is unaltered. The blade is 1.5mm wide with a 30 degree bevel. Opposite it is the same chisel reshaped so that the bevel is less than 10 degrees. One millimetre up from the tip the blade is only .25mm thick. The thinner blade displaces less fragile soundboard wood as it is plunged into the cut. Below it is a reshaped chisel that is also ground narrower to 1.1mm wide. By "walking" this chisel around a curved line that has previously been scored it is possible to make a clean cut through the wood without leaving  a faceted contour. The straight section are cut through with the 1.5mm chisel. I also have reshaped chisels that are 3 and 4mm that I occasionally use.

When necessary, perhaps while removing a waste portion that is next to a fragile rose element, I will bevel the edge of the waste. This provides more room and less resistance to the chisel as it separates the waste from the rose element.

The rose patterns and backing are glued on with fish glue.  I like this glue for this type of operation because I think it causes the paper to shrink less. I use a thicker mixture for the backing and a thinner one for the patterns. Since the rose patterns are on the face I want them to come off easily and cleanly. Sometimes they come off unexpectedly while I'm carving. In that case I carry on if possible but otherwise I stop, glue the offending part back in place and start cutting elsewhere. I remove the paper by wetting a small section lightly with a damp cloth for a few seconds and then touching it with a warm iron also for a few seconds. This releases the glue bond. I then loosen an edge with a knife and finish removing the section of paper with tweezers.

 There is still a lot of work to do. The geometric part of the rose design has a double vein cut into it, the vines need to be contoured and the border needs to be finished. I will do all of that next time.

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