Building my 1852 Torres replica - the back and sides
Updated: Dec 22, 2018
The back of the 1852 Torres is comprised of five sections of Brazilian rosewood separated by 1.5mm wide strips of maple that are angled such that they converge to create an elegant, long, narrow heel. The two outer sections of the back are bookmatched and are the same straight grain, reddish brown as the sides, while the three central sections, unmatched and bounded by four maple fillets, taper their way to the aforementioned elegant, long, narrow heel. Unfortunately, I did not take photos of the assembly of the back on my replica.
For my replica I selected some figured Brazilian rosewood for the three center sections from some stock I had on hand, and I was able to obtain the nice, straight grain, reddish-brown Brazilian for the outer sections and sides from my friend, Mark. Carefully measuring the tapers of the three center sections, I glued them together separated by the four 1.5mm wide maple fillets and the two outer sections and tightly clamped everything with a traditional Spanish clamp using ropes and wedges to tightly and effectively clamp even odd-shaped items. Afterwards, using my FE18 template, I cut the back to shape (about 5mm oversize all around) on my bandsaw and located the three Spanish cedar back braces, the same as on FE18. Normally for the back I would add a radius, but without any information about this I chose to make the back completely flat.
Shown above are the completed oversize back with the Spanish cedar back braces glued in place, a couple of cutoff pieces of the center and outer sections, and finally the completed back finished in French polish of shellac. I was quite pleased with the nice contrast between the inner and outer segments of the back.
Time to prep the sides. Just as the back sections were separated by maple fillets, the sides received a similar treatment with a single band of the same 1.5mm wide maple fillets dividing the sides into approximately equal halves. Again, unfortunately I did not photograph this facet of the process. Shown below, however, are a cutoff section of one of the sides (before being trimmed to proper dimensions) overlaid on the life-size photo from which I worked, showing both the outside and inside.
As shown above, I reinforced the sides on the inside where the maple fillet was sandwiched between the rosewood halves of each side. For this purpose I used Lineco linen tape. It is both acid-free and self-adhesive, and is often used in archival applications mounting photos and mats. Before the linen tape was applied, the sides were thickness sanded to ~1.5mm on my drum sander (final actual finished side thickness varies from 1.24mm to 1.6mm). The linen tape was then applied and the sides were then bent to shape using my Fox-style bender.
So...how did the linen tape hold up under the heat of the bending process? No problems. Usually, when bending, I will spritz the sides with some water, but these sides were bent dry. In the time of Torres, strips of linen were typically soaked in hide glue and applied to these types of joints. Was that done on this original instrument? I have no idea, as I worked only from photos of the exterior of the instrument. However, Torres, and others, generally used some form of reinforcement for these types of joins - linen, wood, or even paper. I knew this tape would work and that the adhesive hold up even under the temperature needed to bend the sides because I had used if before. In 2014, I built a Torres-style instrument with many of the decorative elements of FE01 and FE08, hence the name I gave to it, "Uno y Ocho". The sides had a wide element of Greek keys, bordered on both sides with "ears of wheat" elements. I made several test pieces before finalizing my use of the Lineco self-adhesive linin tape for that instrument.
Below is a photo of my 2014 multi-piece side, "Uno y Ocho", where I previously (and successfully) first used the Lineco self-adhesive linen tape, and the inside of an original Torres, SE127 from 1888, with linen strips reinforcing it's multi-piece sides.
Curiously, however, it doesn't appear that any internal reinforcement was used on the multi-piece back. Very interesting.