Moldings: Soundboard level

The next installment in the molding saga: the wrestplank moldings are complete, and the soundboard area is almost done.


Only the bentside molding remains to be glued down. This must be bent to shape somehow; by hand, perhaps, but it seems to tip forward when forced around the curve, and clamping it flat is challenging because it's so skinny. I might try kerfing it slightly along the inside of the curve to take out some of the bending strain.

Shown resting on the soundboard is the neat little miter box I used to cut all the corner miters. I also used it on the bridge and nut. It has a 54 TPI blade that cuts slowly but extremely smoothly: absolutely no sanding is required to clean up the cut.

Moldings: Tail hitchpin

It's time for moldings... and there are a lot of them on an Italian harpsichord.

First comes the molding that lies along the soundboard edges, which will hide any little gaps between the soundboard and case. These moldings can also serve as places to drive the hitch pins, if one chooses. Another possibility is to drive them through the soundboard just in front of the molding.

The moldings are based on the same profile used to make the bridge and nut—a cove and a little groove—so the decor has a holistic sort of feel to it, with recurrences of the same basic designs.

I've started with the tail molding, which is both thicker and higher than the remaining moldings. This will lessen the downward pressure of the strings on the bass end of the bridge. When the hitch pins are driven through this molding, they'll penetrate it and the soundboard and go a little way into the tail liner, which will help secure this piece against the tension of the bass strings.

The molding glued in place:


Note, at bottom left, some of the other moldings: same profile but much slimmer. These will cover all the remaining junctions between soundboard and case and will also outline the edges of the wrestplank.

Soundboard glue-in

An auspicious day: the soundboard was finally glued in.

Earlier I checked the fit of the board to see if the presence of the case walls affected the fit. It seemed fine except the cheek edge felt a bit tight, so I gave that edge a little rub with coarse sandpaper and the fit was good to go.

After taping the edges of the soundboard and the inside edges of the case to protect against glue squeeze-out, generous amounts of fish glue were applied to the liners and the soundboard was set in place. An arrangement of clamps and cauls held the board against the liners and the upper belly rail. I admit that in a perverse kind of way I looked forward to this moment, as I was finally able to use 47 of the 50 F-clamps I bought last summer, plus a bunch of C-clamps.








The instrument is respectfully dedicated to my friendly harpsichord maker, and has been so inscribed on the underside of the soundboard.

A day later, the glue was dry and the clamps came off. I used my block plane to trim the front edge of the soundboard, which overhung the upper belly rail a smidgen along its length.

It should be clear in the photos above that I already trimmed all the overhanging case edges, which were left long as each piece was glued in (see the photo in the previous post for comparison). I taped each joint to protect the wood from scratches, and, using a Japanese-toothed dovetail saw held flat against the case, I sawed off the excess material at each joint. A little sanding smoothed out the cut edge, although I didn't aim to get the joints exactly flush at this point in time.

Case work: Spine

Time for the spine to go on:


Plenty of clamps were needed, and a couple of spring clamps at the tip to clamp the bevel joint (51.5 degrees) together. The spring clamps are kept from sliding off the tip with strips of very coarse sandpaper.

To allow the installation of the registers later on, a small rectangular spine window was cut through the spine in line with the left end of the gap between the wrestplank and the upper belly rail.

Case work: Cheek

Today the cheek was glued on:


It was a lengthy job to fit the cheek to the bentside. Despite the block I clamped to the bentside liner, the treble corner of the bentside did curl inwards a little, so I was forced to sand the bevelled cheek edge (32 degrees) all afternoon until I matched the slightly curved profile of the bentside edge.

The sticks allow clamping pressure to be directed to wrestplank level, as any effort to clamp along the upper edge of the cheek would probably split the case material, which is unsupported above the wrestplank. Similar sticks were temporarily attached to the spine side of the wrestplank supports with double-sided tape, and clamps placed across the instrument squeezed the upper and lower ends of these together.

Case work details

Cutting bevels at the joints between various case parts is a little trickier than it might seem. The Trasuntino has rather sharp corners and the required angles cannot be set directly on most power tools, which only go up to 45 degrees. Such tools are designed to help cut things square, or to make up angles that add up to 90 degrees (two 45-degree miters, for example).

To cut an angle of more than 45 degrees—and all the case bevels, except at the cheek-bentside corner, exceed 45 degrees—I built the following table saw jig, which stands the workpiece up on end instead of flat on the saw table. By changing the orientation with respect to the saw blade, the complementary angle can be cut, which will now be less than 45 degrees.


The jig slides along the saw fence, and the table is tilted to the appropriate cutting angle. A sacrificial piece of plywood keeps the blade from slicing into the jig, and a sample piece of yellow cedar is shown in the proper position.

I'm using a Shopsmith Mark V Model 510 saw system; with suitable accessories it can also operate as a jointer, sander, bandsaw and drill press. It's a good tool, but the tilting table makes angled cuts a bit tricky. Cutting the spine bevel was a real production: my father and I dragged the saw out of the garage onto the driveway so that the 92" long spine wouldn't hit the roof rafters during the cut.

The front edge of the cheek and spine are cut out decoratively on most Italian harpsichords. I glued two additional layers of wood against the inside face of each case piece, making a sandwich of two outer layers of yellow cedar and a thinner middle layer of walnut. The grain of the middle piece is at right angles to the other two. Below, some walnut is glued to the outer layer of cedar:


I made a plywood template from a tracing of the original Trasuntino cheek profile shown on my drawing. When the three-layer sandwich was ready, I traced the template profile onto it in pencil, cut most of the waste out with a jigsaw shy of the line, then attached the template with double-sided tape and ran the whole assembly against a piloted flush-trimming router bit to cut the exact final shape. Below are the spine and cheek cut-outs: the cheek has been sanded thoroughly while the spine is still rough from the router table:


I sharpened some of the corners of the profile on the cheek, which are naturally softened by the round router bit.

It's interesting to note that these layered cutouts not only look good but add strength to an otherwise weak area of the case: the sides are attached only along the baseboard at this point. Many cosmetic elements on Italian instruments turn out to have strengthening properties when one looks more closely at them.

Case work: Tail

After getting the bentside attached, I found I still had time for a little dessert, as it were, so I decided to attach the tail piece next. The only tricky part was to determine the bevel on the tail, which slips in behind the overhanging edge of the bentside. Some trial-and-error cutting eventually determined this to be 57 degrees. I found I also had to cross-cut the tail piece at 1 degree off square before cutting the bevel; otherwise a gap occurred where the two pieces met above the liners. Somehow things ended up slightly out of square, but the slight skew in the cut compensated nicely.

The glueup procedure was largely the same as for the bentside, but much more relaxed and without any bending required. I didn't bother pre-drilling the screw holes before gluing as I did with the bentside, as now there were only half a dozen to deal with compared to the 36 I drilled in the bentside.


The slotted rectangular plywood block is an idea I read about in several sources. I don't know if it has a proper name, but someone unofficially referred to it as a "jamb cleat". The liner and case material slip into the groove, then a couple of wedges are pushed in to provide clamping pressure. I installed one right at the point of the tail, a position that would be hard to clamp any other way:


The screws keep the cleat from sliding off the point as the wedge is forced in.