Seeker wrote:

replying to Joe Travis, Seeker wrote:
I'm wanting to try this as well. My best guess is to create a vertical
mold
out of wood. Basically a pair of flat sheets of wood sandwiched with
spacers. It might be destroyed after a few pours but it would make thin
flat sheets.

Yes, the pipe organ makers did it like this: They had a leveled surface
plate, placed "dams" in the right place to limit the size and poured lead,
tin or solder in to the desired thickness. There were weights to prevent
the dams from moving.

So, they did it horizontally.

Jon