Horse and baseboard united

Nothing earth-shaking, perhaps, but today the horse was at last glued onto the baseboard:



Before doing so, the joints between the wrestplank support blocks and the lower belly rail were dowelled. Since I intend to dowel into the lower edge of the belly rail and the two knees supporting it, I traced out the position of these components with pencil, and just before gluing, I drilled a series of tiny holes through the baseboard, positioning them at the midpoint of the thickness of the knees and belly rail. When the glue is dry, I'll drill larger dowel holes from beneath, using these little ones as markers, without having to guess where the components are on the other side of the baseboard.

I've also laid out the positions of the knees in pencil, and once again I'll drill small locator holes to help me dowel them after they are glued down.

Baseboard: Cutting out the bentside and tail

I've been busy with various professional commitments since my last post, but I managed to find a few spare moments to work on the baseboard.

In describing how the curvature of the bentside was laid out, I mentioned that the bentside shape had to be corrected at the tip of the instrument. I managed to do so by nudging the far end of my plastic strip (shown in an earlier photo below) about an inch to the right, and then I traced out the final position of the bentside parallel to the strip and 95 mm to the right. I also drew a line parallel to the left side of the instrument at a distance of 185 mm. At the point where my bentside curve encountered this straight line, the bentside ended and a straight line angling leftwards at 40 degrees defined the tail of the harpsichord. Where this line met the left edge of the baseboard denoted the final length of the instrument, which worked out to 2245 mm (about 88.5"), just a whisker off from the original 2242 mm.

Then it was simply a matter of taking the baseboard outside and sawing out the curve with a jigsaw. I smoothed the edge with a file and let my mother, who has a good touch for sanding, clean up the edge even further:


The finished product:

Baseboard: Making the breadboard edge

After picking up a rabbeting router bit set at the Home Depot, I cut a half-inch wide tongue on the front edge of the bottom. Next, I ripped a strip of leftover red cedar to a 1" width and, after a bit of trial and error, routed into it a groove to match the width and thickness of the tongue. Here's a photo of the pieces, dry-fit together:


This strip is known as a breadboard edge and is used on large panels such as tabletops to hide the end grain. Here it provides a suitable surface for gluing on the case mouldings that will come later as a decorative embellishment.

Note that the bottom and breadboard are both still oversize at this point, so they need not be of identical length. The pencil tick on the light-coloured board (slightly below the X on the breadboard) marks the cutoff point that will establish the final width of the baseboard.

Baseboard: Trimming the front edge

After my two workers finished cleaning up the dried glue, I took the baseboard outside and sanded both faces with 100 followed by 150 grit paper. I used a random-orbit sander, which also helped to take out a few very minor irregularities in the joints between boards. Both my father and I agree that our work joining up the boards was very good: the sander needed to dwell on only a few spots to get everything level.

Next, we clamped a straightedge along the front, making sure it was perpendicular to the long side, and crosscut the front edge straight with a handheld circular saw. The process of biscuit joinery allows some slight sideways play in the boards when they're glued up, so the ends of the boards are usually a few millimetres away from being in a perfect line. As long as you cut the ends off, all is well and a straight edge is restored.

Baseboard: Gluing together

All the boards making up the bottom were jointed cleanly on one edge, ripped along the other edge and jointed again. The final orientation of all the boards was decided upon and all were pencil-marked to make sure they didn't get flipped onto the wrong face or turned end-for-end by mistake.

The boards will be joined with glue and biscuits, which are little football-shaped splines made of beechwood that go into slots cut on a board's edge with a special power tool.


Biscuits help reinforce the joints and make it easy to align the edges during glue-up. Without biscuits the boards, slippery with glue, would slide around quite a bit while the clamps were being put on. An advantage of biscuit joinery is that minor bowing of the boards along their length can be taken out: the biscuit slots are all cut at the same position measured below the boards' upper faces, so the faces are all pulled into the same plane during assembly.

To start with, the four right-hand boards were glued up:


After this assembly sat in the clamps for a few hours, the remaining two long boards were glued on:

Baseboard: Selecting boards

In many harpsichords, the case sides are a major structural component made early on, and the bottom gets nailed to them much later. The casework of such instruments forms a rim that other components are attached to, so the boards it is made of must be strong and fairly thick. The bottom, or baseboard, of an Italianate instrument (this category includes some south German instruments made along the same lines) is, on the other hand, a major structural component. Various items are attached to the bottom to make a kind of inner frame, and thin case sides are glued all around this frame.

My instrument will have its bottom from that western red cedar I recently bought. A&M resawed it to slightly over 3/4" and our planing extravaganza got everything down to around 5/8" thick. This is thicker than some historical Italianate bottoms (only 1/2" on some instruments), but my research suggests that western red cedar isn't as stiff as other softwoods, so a bit extra can't hurt. It's pretty light material, and is said to be quite stable.

To cut the boards to length, I simply placed the first board on the left edge of the drawing and looked to see how much of the drawing was left exposed. Each succeeding board was then measured from the front edge of the instrument to the bentside line on the drawing where it disappeared under the existing board, cut to that size plus about 4" extra for safety, and placed right next to the previous board.

The process continued until the outline of the instrument was completely concealed.

To make sure I would have enough material, I estimated the area of the baseboard by calculating it as a triangle sitting atop a rectangle. This area was divided by the width of the boards I could get and translated into a linear measurement, as if of one enormously long board. Then it was simply a question of getting enough individual boards to sum up to that one imaginary mega-board. The only thing to be careful of was to ensure that the leftmost boards were the full length of the instrument (about 92").