Humble beginnings

various wax castings on workbench

We all start somewhere. The spouts I sell start with a wax casting. It's the first step in a process called investment casting. So I sit in the workshop, melt wax and pour it into silicone molds. The process is decidedly anti-climactic. It's rather finicky work. The first casting never works because the mold is cold. The second one may have some minor flaws. By the time the third is cast, the mold has heated up enough that the process moves along rather nicely. But as the molds heat up the waxes take longer to cool. If I pull them out when they've not cooled enough they can deform. If I wait too long and they are too cold, they're impossible to remove. Every process has it's own little challenges.

wax casting and it's mold and core

Ideally the parts would come out of the mold in perfect condition, but that never happens. The molds use are filled by hand and the casting are such that they provide places for air bubbles to get trapped in overhangs and hidden corners. I move the molds around to allow the bubbles to float to the surface. But, once the wax begins to solidify, the bubbles are trapped.

Once the spouts are out of the mold they usually need some care and attention. The castings usually have some sort of imperfection, some flashing and an air bubble or two. All of the imperfections will be transferred to the bronze casting. It's a lot easier to make repairs to the waxes than to the castings. Holes in the metal castings need to be welded shut, ground down and sanded to match the adjoining surface. A hole in a wax part just needs to be filled in with a drop of hot wax and shaped with a knife or scraping tool. The time difference is tremendous. So, the castings are cared for and groomed in the wax stage so they can become nice, strong, beautiful bronzes.

I'll be spending the next few days going over the wax castings to make sure there are no imperfections. It's decidedly unromantic, but it needs to be done. Then it's off to be turned into bronze parts. That's a fascinating process that's well explained on the Wikipedia page about investment casting

Well, it's off to the workshop - Waterbearing out.