Re: hand casting pewter
I had chance to play with the pewter and an rtv silicone mold. I had used the mold for other experiments but it was suitable for testing.
The solder paste idea worked, but not if the thickness of the pewter is greater than about 1/8" or so. Some areas, that were about 1/4" thick had some of the gassing affect. There was some loss of detail with the paste, and a bit of a smoothing affect that may even be desirable. Using the liquid form may help as could carving the details a little deeper in the original.
I didn't try the soot, but I will.
I think some of the problem is related to the metal being too hot for the rtv silicone. Hence the thincker metal causing a problem. I had been dripping the metal slowly on to the rtv, and that worked, but it cooled too much, and did not always form a strong bond to previous metal. I thought it would be a simple way to cast in 3d.
Seems like I may have to invest in lower temperature pewter, if I want to cast in rtv molds. Since I need to buy it in bulk, I think I would like to try casting in a plaster/sand mix and try something thin, where I use a two-sided silicone mold. Thin would not be a disadvantage, as it uses less metal, but it might cool the metal too quickly.
I have a lot on my plate, right now, but will be working on the idea in my "spare" moments.
It will be a while before I can build a small smelting furnace and try my hand at a few bronze things. Need to build the workshop first. Pewter seems like it could be an intermediate step.
thanks a lot for the suggestions,