So after replacing an 18 lbs shark DR weight last week for $130, I think it might be better to buy a mould and make them myself. My son has been into melting metals for the last ten years as a hobby, so we have the crucible and the furnace to be able to melt lead with no issues.

I've been on the search for an 18 lbs shark DR weight mould, but I can only find ball moulds. Any ideas where I can find what I'm looking for? Something like this:



The other solutions to acquire a mould are:

1. Sand cast the mould using a 3d printed model and sand.
2. Make the mould out of wood
3. Buy a block of stainless steel and have my son CNC the mould at his university.