Casting Plumbum

To construct my own plumbata I needed to learn how to cast lead which is used both as a weight for the weapon and to strengthen the connection point where the wood shaft and metal head came together. Pure lead melts at 621.5f, a temperature low enough to melt over a wood or charcoal fire. I decided that, for my first attempts, I would purchase a modern pot to melt the lead in but as I learn more about the process I’ll try it over a fire. I began with some old fishing weights that were my father’s before he passed away. These weights were pretty oxidized and dirty so I expected them to put off a lot of fumes which are very dangerous. I was not wrong on my assumption. I set up the melting pot outside on a covered deck so I was able to place the lead in the melting pot and go inside the house to watch the process safely away from the fumes. Once the lead had melted and the smoking stopped it was ready to pour.

I was a little concerned about being able to get the rings that were molded into the fishing weights to tie the line to out of the lead before pouring it into the molds. I found that this was not a problem. The lead was denser than the rings so they floated on top with the rest of the slag. As I poured the molten lead into the molds the slag and the rings stayed in the pot. Once all the lead had been poured I just had to invert the pot and tap it gently and this waste simply fell out.

In my research I had discovered that it was possible to pour molten lead directly into a mold to connect the wood and metal parts of the plumbata. I wanted to test this theory so I used a splinter of wood to stir the molten lead before pouring it trying to push the slag away from the pouring spout. After using this same stick about 20 times to do this there was just a little charring on one end. This seemed to indicate that it is possible to pour the molten lead into a mold connecting the two parts of the plumbata without destroying the wood shaft.

As you can see in the images, I used an old aluminum mini muffin tin as a mold to cast my purified lead. I wasn’t sure how well this would work but after using it there was absolutely no apparent damage or discoloration. This is important because one theory on making plumbata is that 2 part copper molds were used to form the lead. Copper has a higher melting point than aluminum so it is feasible that it could have been done this way without destroying the molds.