I need to make some small parts from steel such as 4130. They're about the size of one of a pair of standard dice, maybe 1/2" in the longest dimension, of very complex shape. It would take several setups and some special fixturing to make them, but only two of the dimensions are critical.
I have a book called "Lost Wax or Investment Casting" by James E. Sopcak. It was printed in 1986 from article apparently written in the 1950s or 1960s. He describes a homebuilt setup for making small investment castings in gold, silver, or bronze. His method (which may be quite common, for all I know...) is to cast the investment, burn out the wax pattern, and then put a piece of metal in a depression on the top of the investment, with a very small sprue. He heats the metal with an oxyacetylene torch, then uses a fixture with compressed air to force the molten metal into the mold. Surface tension keeps the metal from filling the investment until forced in by air.
There's no separate furnace, crucible, or handling of the molten metal; it's all done right on the mold.
This is all described in basic DIY fashion, and I'm particularly interested because I have most of the materials to follow the book on hand. However, I'm curious if there might be a problem with trying to cast 4130 this way. It's a gas-weldable alloy, and Sopcak recommends a neutral flame.
All of the ferrous hobby-casting stuff I've found seems to be oriented toward iron, for ornamental use or engine castings...
Has anyone here cast steel this way? Is there a cheaper/better/simpler way?