Day 8: Laminating back, bending sides, struts

Today, we began by laminating the back with the cherry and walnut veneers that we glued together last week. Using a scraper and abrasive paper, I ensured the joint was clean of glue and smooth, as well as sanding the cherry veneer to ensure a good flat gluing surface. Then, having pencilled the plantilla outline on the area of the walnut veneer which will show through the soundhole, I sanded it to bring out the grain. It was important to get the centre line of the burr walnut veneer in line with the centre of the back so that when looking through the soundhole, the grain of the walnut veneer was correctly placed. Because I am laminating the back, there is no need to strengthen it with a cross-grain reinforcing strip (pp.221-2).

Next, I bent the walnut sides, constantly checking the shape against an outline of the plantilla. I’m using the Friederich body plan from Roy’s book. Once the ribs were bent to the correct shape I clamped each of them to a separate jig to help retain their shape.

Next, I cut a block of quarter sawn spruce into 23 strips for the struts and harmonic bars. There are 18 struts for the lattice. The struts will be further planed and carved to the correct size and shape and then reinforced with carbon fibre strips. Today, they were rough cut at 12 x 4 mm but the final width will be 2.0 to 2.5 mm. The height will vary, from 6 or 7mm over bridge tapering down slightly towards periphery.

Finally, throughout the day I was attempting to create the log for the motif of the rosette. As I said in an earlier post, I wasn’t happy with the first attempt because the ends of the square lines in each plank didn’t align correctly due to them not being uniformly 1mm square.

Today corresponded to Roy’s book pp. 209-10; 229-232.

 

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