I made my own belly weight mold out of 1/4 x 1 x 48-inch aluminum stock available at Lowe's, Home Depot, etc. I drilled two index holes at opposite corners so that the mold halves would line up when placed together. Then, I drilled the hole for the lead. Next, I drilled a 1/8" hole for my screw eye (which I twist out of stainless steel welding wire). Finally, I opened the mold and, using a bradpoint drill bit, drilled a shallow hole at the end of my 1/8" hole on both sides of the mold for the loop on my screw eye. When I pour my belly weights, I insert the screw eye into the mold, close the mold, and pour. Before I open the mold, I clamp the mold in a vise and use a flat chisel to trim the excess lead off. When I open the mold, my weights are ready to use.