CLAVICHORD REFURBISHMENT AND COMPLETION
A SECOND GO AT AN EARLY BUILD REINFORCES THE UNIQUE STYLE OF ITS CREATOR
In a previous article in The Shed — September/October 2019, Issue 86 — I described the basic clavichord design and the historic construction of this one. (photo 1) It was limited at the time of the construction by ‘learning as you go’ — there was no Internet, and getting within a metre of old clavichords was forbidden! The chief disadvantage had been trying to adapt keys from an old piano “which would make a good start”. It didn’t. It made much more work and complication, rather than saving it.
The end result was quite good musically but, rather than spend much effort making a case for it, I thought it would be more worthwhile to put all I had learned to good use, so I gave the clavichord to my more musical brother and made a second one, starting from scratch. The basics were already designed, and I could avoid most of the previous difficulties — and the overhanging soundboard.
Soon after I so generously gave the clavichord to my brother, he found in an antique shop a Broadwood ‘square piano’, which was quite easily restored and was also a very elegant piece of furniture. Then he inherited the family Steinway grand piano.
Why not do it all again?
My second clavichord was in many
Nostalgia struck! Here was a retirement project. On YouTube,
I had since seen and heard very old clavichords with odder-shaped soundboards than mine — and I still had the materials and trim for the case.
We screwed lengths of chipboard round the frame, tacked on thin ply panels, and I brought it back as an extra ‘suitcase’. (photo 1)
Restoration begins
The plane of the frame was twisted but the main warping was beneath the keys. (photo 4) The piece I had laminated there was coming unglued — and was too thin. It came off easily. I glued on a thicker, stronger piece of hardwood, clamping it with a slightly negative curve while the glue set, almost eliminating the curve. (photo 4a)
The next thing was to reattach the soundboard. I thought if I could lift the strings rather than taking them all off, I could slide it out, clean the area, and refix it — but things are never so simple.
I slid a flat Bowmac bracket beneath the strings, wedged it up front and back just enough to free the strings from the bridge pins, and managed to slide the soundboard out.
7) It had partly sagged, so I reglued the soundbar and added two small ones where the stress had depressed it. (photo 8) I took the opportunity of making more ‘clear air’ under the front of the soundboard by chamfering off more of the frame. (photo 9) After repairing a crack, I French polished the soundboard again — a satisfying job.
(photo 10)
I slid the soundboard back beneath the strings and, in gluing it, arranged pressure all around, including the
edge where it was beneath the strings — another interesting exercise. (photo 11) However, when I removed the elevating bar, the strings barely touched the bridge — oh dear!
Movement had eliminated any downbearing pressure. Screwing the tuning pins lower involved removing each string after all. Restringing 53 pairs of strings was a bit tedious but I had no option.
Redoing the keys
The keys looked awful, with the old blocked-off balance pin holes and the rough ends where removal of the original weights near the shortened ends had left holes. (photos 1, 12)
I filled these with half-inch dowels, reshaped the ends, and applied preglued pine veneer to the top of each note. (photo 13) The top (played) part of each note was the original (but shortened) ivory and ebony. Like most keyboards of the early period, the black and white contrast would more usually be reversed, using lighter and darker timber, so I stripped them off. On ‘clavi 2’, I had replaced the top of the naturals with thin strips of teak and simply added ivory to the front of the ebony accidentals. (photo 2)
This time, I selected pre-glued wenge veneer for the naturals. For the accidentals, I planed down a piece of maple to half-inch thick, then put it through the table saw at a five-degree angle to give the tapered side profile — seen with ebony prototype lower right of photo 14.
I reversed the plank for the second side, adjusting the table saw fence to produce strips the right width; each was long enough to make three tops. I cut these off to length at a slight angle to complete the appropriate profile, fine sanding them on the linisher. For the finish on all the notes, I used fine sandpaper and boiled linseed oil. This has dried to a nice finish that is smooth to play on and easily cleaned.
Pre-purchased items
Like so many projects, the ‘main’ part may be hardly half the work — as those who have bought a boat to fit out will know.
I still had the mahogany ply I had chosen years ago for its appropriate grain, lengths of moulding for the edges, and even the lock. I cut the top panel to shape slightly oversized and debated whether to hinge it at the back, like most clavichords. This can form a music rest, although it ends up a little far away so some makers hinge the length of the top. I think this spoils the look and interrupts what may be a nice panel. (photo 15)
I had already tapered the back, and I felt to hinge the top of the case at the right end would look more interesting, if I could still make room for the height of the music.
I hung the panel above the instrument to check. (photos 16) No contest — but hinging at the right end meant the top would have to be removable to give room for the key when tuning.
A length of small piano hinge, with several screws, would have been
preferable for the thin top, but there was a slight bow in the end, which I couldn’t plane out, so I used two hinges. There is some advantage in having the other edge panels also removable for access, particularly to be able to slide out the keys on the balance bar more easily (as on ‘Clavi 2’) if necessary. On this one, the bar dropped out below. (photos 17, 20) I therefore arranged all four sides on little brass keyhole inserts, with small brass turnbuckles recessed under the lower edge. (photos 18–20)
Standing firm
I felt the instrument should be portable but stand firmly on its own legs. On the four original screw-in legs, this was never really the case.
I had to deal with warping, as described earlier (photo 4), but what could not be corrected was some twist in the frame. This had developed early on, and to take account of it I had needed to adjust the four screw-in legs, which were neither level nor perpendicular to the floor on the left, where they were quite close together.
I decided a composite single one at this end would solve the problem — particularly if it didn’t draw attention by not looking upright. A table with three legs will stand firmly anywhere, even if the floor is not level or the top is warped.
I had made a wall shelf for our home’s curved hall from an old bookshelf. The remainder was a long taper with a curved side, which gave me an idea for twin tapered legs on the right. I cut the centre out to form a more elegant leg.
For the second, I cut a similar curved length which I married to a straight piece; adding a solid section at the top to make a matching leg. I designed a composite third one for the left end in a style to match these, with two curved sides. (photos 19, 20)
original plan, (photo 22) it would be difficult to make it rigid enough yet still removable to store in the closed instrument. Instead, if I made a name board and continued it across to the side frame, I could form a box.
At the right end, the name board would not clear the lowest strings and arranging support there was tricky. Beside the top and bottom notes, there was just a 3mm gap. (photo 1)
From my 9mm ply, I routed off all but 2.5mm, and secured a small panel beside the notes at each end.
side, and is supported by a small projection below. (photos 25, 28)
I had to cut a slot to give clearance for the bottom two strings. On the left, the name board slides into a recess in the small panel. (photo 26)
The back of the box was thinned like the two small panels and screwed —