[geohan]

FWIW,I saw a lead balast keel for a wooden boat being made in a welded steel form (melting pot)set up on concrete blocks and fired with charcoal using the exhaust blast from a vacuum cleaner. The dimensions of the form were about 1'' wide by 1.5''high by 6''long. A slow cool down minimized the shrinkage cavity and the extracted keel looked pretty good.