Clavichord Day 21 - Easing the Keys, Thumbnails

Earlier, we eased the keys at the balance pin/balance hole. Now it was time to ease the back of the key, where the thumbnail goes into the slots in the rack. The key has to move freely up and down, so the thumbnail needed to be sanded a bit thinner. However, we do not want the keys moving side to side at all, so we had to be careful just HOW MUCH to sand off.

The first step was just to round off the thumbnails we cut earlier.


Then, the key would be tested to see how loosely it fit into the rack.


Invariably, they were too tight. So, we used a soft charcoal pencil and rubbed the coal onto the thumbnail on both sides. Then, after putting it back into the rack and moving the key up and down, the charcoal became reflective wherever it was still rubbing inside the slot:


That gave us a clue exactly where it still needed to be sanded. That way, we wouldn't accidentally sand too much and make the key too loose.

Here it is after 45 painstaking keys!

Clavichord Day 20 - Sharps and Hitchpins

Today, we started by checking out the sharps. These are the little dark keys on the keyboard, and they are eventually glued onto some of the key levers we have already worked with. First, they each needed to be dulled a bit with the file and sandpaper, to get all the tool marks off of them and to dull all those sharp edges which would otherwise hurt the player's hands.


Keeping in with the decorative concept we began earlier, we decided to stain each of the sharps for more contrast on the keyboard.



While those dried, we picked up our handy nail set and tapped in the small hitchpins, each into its hole in the hitchpin rail.


Those that didn't have enough of a backward lean, against the eventual pull of the strings, were tapped from the side with a block of wood and hammer to get the right tilt.

A look at the hitchpins in place.


A bit of a short day. More work on the keyboard to come.

Clavichord Day 19 - Balance Pins, Backrail Cloth, Punchings

Continuing on with the keyboard, we started out the day getting the balance pins into the balance rail. First, they were lightly tapped in.


Each pin should only stick out 5/8", so we made a small block at that height and drilled a hole in it. With this block set over each pin, it was easy to hammer them down to the right depth.




Here's a look from the front with the nameboard in place. The 5/8" height of each balance pin is perfect for sitting just below the nameboard without touching.


Here's an illustration of the "see-saw" point I made yesterday about the keys. Notice the key sitting around a balance pin in the center. The thumbnail we previously glued onto the back of the key sits in its respective slot in the guide rack.


The backs of the keys, as seen above, will constantly be swinging up and down when the instrument is being played. Thus, the backs of the keys will be landing on that backrail quite often. To soften that blow, we now cut to size and nailed in place a length of black wool along the top ledge of the backrail, where the backs of the keys rest.




The keys will also get a lot of action at the balance pin, so to protect the centers of the keys we put on each balance pin a small red felt punching.


Here's a look at the case with the black wool on the backrail and the red punchings on the balance pins. Looks neat!

Clavichord Day 18 - ACTION! Easing Keys and Thumbnails

No more cabinetry for now. Oiling and waxing the case will come later. Today, we moved on to the ACTION, meaning the mechanisms of the clavichord that have to do with actually playing the instrument!

Here is a look at the pre-cut keyboard, as it came in the kit.


To keep track of all 45 keys, we numbered each one This was done along the line where the balance holes were drilled, because the nameboard will cover this area.


See, the keys themselves are kind of like see-saws. In the middle of each key is a hole for the balance pin., the fulcrum of the see-saw. We have to make sure that the keys swing up and down freely, but without too much looseness. Getting them to the right looseness is called EASING the keys, and that's what we started to do next.

First, we quickly created an "easing tool" out of a spare stick of wood and a balance pin.


Then, a key was put on the tool. We rotated each key around and around, and pushed the see-saw up and down, to get the key to move more freely.


That was only the first stage of EASING, and we will come back to that later.

Now, when we install each key in the instrument, what is to keep each key from rotating round and round on the balance pin? Well, remember the guide rack in the back of the instrument with the vertical slots carved in? Here's an old photo:


In the back of each key will go a thumbnail, and each thumbnail will go into its corresponding slot in the guide rack. This keeps the keys from moving side to side, and only up and down.

We had a long piece of thumbnail material (the same one we used for the nameboard - see DAY 10). Here's the thumbnail wood in the back of a key:


We wanted about 3/16" of thumbnail protruding from each key, so that was measured and marked.


Then, the thumbnail was removed and we put glue into the kerf in the key.


The thumbnail was inserted again and glued in.


Finally, the thumbnail was cut with scissors at the mark.


Mind you, pretty much every step on the keyboard has to be done 45 times--once for each key. Here is the keyboard with all the thumbnails in place.

Clavichord Day 17 - Gold Leaf

This was an exciting day, since we got to finish up on the decoration of the instrument!

First, a couple of coats of shellac were put onto the tortoiseshell to seal it in and give it a shine.


Then, at long last, the tape was removed! Here is the lid and toolbox cover, with the pattern all completed.


Of course, that is not the final product. We want these panels of tortoiseshell to be framed by bands of gold leaf. We decided on bands 1/8" wide, but we wanted to test a small area to see how that would look. First, we masked at that width.


Then, to prime the raw wood, we used a red sealant made by Rolco. The added bonus we found from this product is that it develops a tacky feel after a few minutes. So, rather than seal the wood and then apply a glue sizing later, we did it all in one step.


Painting on the sealer/sizing:


Once the sealer was tacky, on came the gold metal leaf.



A look at the test piece, perfect!


The rest of the case, lid, fallboard, and toolbox were also leafed.


And FINALLY, we have finished the decorating! Before and after:




Before we are technically done with the case, a few finishing touches remain (plus the oiling and waxing), but the hard part is done!

Clavichord Day 16 - Faux Tortoiseshell (continued)

All the work for today was about softening the look of the tortoiseshell to a nice subtle finish. The first step was sanding.




To show it more clearly, here it is before sanding:


And after sanding:


Then, a very thin coat of yellow ocher was put over the whole thing:


And after the ocher layer, came another of burnt sienna for a reddish glaze. The point of both these layers was again to create a warm and rich translucency and to soften the harshness of the pattern. Here is the final product:




Tomorrow, the shellac finish will go on, and maybe even the gold leaf bands to surround the tortoiseshell. Then (at last) the tape should come off, and we will be able to see what we've done!