Maker Jim: Pewter
September 2014 - I've just taken a short course in pewter casting. Wow, this is simple. We used plaster of paris to make two small blocks about 4x4x1. We let them dry overnight so that all the water is gone. Then used "fine" sandpaper on a table to get one surface of each very flat. Using tools like a flattened big nail and dentist picks, we carved our design into the surface. With a glove we held the two sides together and spooned in some melted pewter from a solder pot. Simple and easy to do. This page will document the things I learn along the way. Enjoy.
What pewter alloy to buy?
I found little guidance on which alloy to buy. Here's what I got from rotometals.com
Britannia: 92% Tin, 7.75% Antimony, 0.25% Copper
The copper makes the metal more ductile; easier to form with a hammer. Melts at 563 degrees, pours at 650.
R92: 92% Tin, 8% Antimony
Melts at 466 degrees.
R98: 98% Tin, 1.5% Bismuth, 0.5% Copper
Less shrinkage, good for fine detail. Melts at 466-590 degrees.
This is my first ever mold. Note the big pouring cup at the top and the large sprues. The gates into the design are smaller, but bigger than I expected. The scratch marks are to let air escape. I neede more of them than I expected.
The resulting two horses after removing the sprues with diagonal cutters. Not bad for the first time.