The notches are really designed to protect the demarcation point between the second score line and the sanding I will do to round off the edges of the keys. I will eventually use a thin strip of sandpaper to round off the edges and the notches will keep my sanding accurate. The photo below illustrates this nicely.
I started notching with a knock-off X-Acto knife I purchased on eBay and I ended up breaking two of the knives that came in the three-pack. The first blade went flying past my head and the second almost cut my hand. I then decided to purchase a good, quality razor knife from Woodcrafters here in my beloved Portland. The handle is just the right size, the blades are tempered steel and the craftsmanship is outstanding.
I then proceeded to cut the notches - and also cut right through the end of the keys, taking the scored parts right off. And I also almost took off part of my thumb. Not dangerous, frustrating or in any way devastating at all. Now, I will have to plane off the two key tops I destroyed and start over with them. I'm not looking forward to that process, but it's just wood. I'll get it.
As you may know, I keep a Facebook project page that has sparked the interest of Australian harpsichord builder, Andrew Nolan. He asks me clarifying questions and makes salient suggestions on the page from time to time. Recently, he reminded me that the mask I was using for sanding paint and wood was completely ineffective against airborne particles of pretty much any kind. I bought a nice HEPA filtered mask on eBay for $15 at his suggestion.
I asked him about my notching dilemma and he said he simply puts the keys in a small miter box and uses a file with a flat side (the one against the score side) to round the key tops - you know, like they did 600 years ago. Similar to my own miter box solution for cutting the natural key tops, this one was staring me in the face and way too simple for me to come up with on my own. Clearly, I need to keep the KISS method in mind as I proceed.
The end result of all of this will look very much like the keys on the left in the photo below.
Now that I have a simple solution to what seemed an nearly insurmountable problem, I can proceed once again with abandon.
Until next time...