I've gone with impatience and foregone the second coat of silicone.

I've taken some of the aforementioned ancient Bondo resin and mixed it with some equally ancient hand-chopped fiberglass and smeared it over the cured silicone. The clay prototype is still inside.


No, it doesn't look pretty does it? If you look closely, you might be able to see some stray glass fibers. I am a little concerned about my ability to pull the stick out, which reminds me that I'd better clear out the area where the key turns.

Hopefully when the resin cures, I can peel the lot off the plastic drop cloth, cut off the excess silicone, then I'll have a nice rigid mold for the second half of my prototype.