Casting toy soldiers is similar to the injection molding process used to make plastic toy soldiers, only the casting material relies on gravity rather than a pressurized pump to distribute the molding material throughout the mold. Cast metal soldiers can be highly detailed using today's tin-based low melting point alloys. Often called “lead soldiers,” metal soldier figures have not been made from lead since its use was banned in children's toys in 1966. Today's commercial molds provide highly detailed models which, when painted, show a high degree of detail.
Lay the commercial mold halves flat on the table and brush a thin coat of mold release solution over the inside of the impression and between the halves of the mold plate to insure proper separation and release of the figure once molded and cooled.
Press the halves of the mold together, making sure to align any guide bars or pins and the pour holes. If it's a large mold or if it contains multiple figures on the same mold blank it may have multiple pour holes. Wrap the outside with heavy duty rubber bands, even if the mold comes with its own snaps or fastener. The tighter the halves come together, the less trouble you'll have with flashing and mismolded parts.
Cut off and weigh bits of the casting metal to make sure you have enough to pour the figure or figures in one pour. Doing it in a single pour helps prevent gaps in the mold and the formation of air bubbles. A small figure can use as little as 12 grams and a large one can use 250 grams of metal or more. Use a toothpick to make sure the pour holes in the mold are clear and then put the metal pieces into the ladle.
Use the appropriate heat source to heat the ladle and thoroughly melt the casting metal. Different alloys have different melting points. Tin/bismuth alloy melts about about 160 degrees, for instance. You can reach that temperature with a candle flame, while harder metals may require heating over a Bunsen burner or propane torch.
Decant the molten metal from the ladle into the pour holes. Pour slowly with the mold turned so the pour hole or holes are on the high side. Make sure the metal is hot and fully liquefied so it can flow throughout the mold. This prevents cavities and air holes from forming during casting.
Allow the mold to cool on a heat resistant surface for a half hour or more before removing the rubber bands and fasteners. Carefully separate the mold halves. You may have to gently lift the corners of the figure from the mold with the tip of your hobby knife to release it from the mold. Work slowly to avoid damaging the mold or the figure.
Trim the figure with your hobby knife to remove any flashing or bleeds and to remove the pour holes or extraneous mold channels. Use fine sandpaper to sand away seams, trim marks and imperfections acquired during the pour.
Paint and clear coat your metal soldiers following picture color guides of the original uniforms and equipment of the soldier models you have made. A hobby shop or on-line hobby supplier will be able to sell you paints in military colors that are specifically designed for painting metal figures.
If the casting turns out badly, simply remelt the figure and try again till you get it right. It may take several times to get a well made figure. Use gloves when handling freshly molded figures to prevent the oil from your hands getting on the figure before you've painted it. Don't dip the mold in cold water to accelerate cooling, as this can cause uneven cooling and damage the figure when you try to remove it from the mold. Only use paint that is made for the kind of metal you used in casting the figures.
Don't forget to wear gloves when handling hot metal. Wear eye protection in case hot metals sputter during heating and wear thicker clothing or an apron while handling the ladle with hot metal in it. Be sure your work table is protected from hot tools and spills of hot metal. Be careful not to drop still-warm figures while removing from molds to prevent damage to the malleable metal.