Pewter miniatures are commonplace in tabletop wargaming, where armies of tiny painted figures face off across battlefields of carefully sculpted foam terrain. Pewter is an easy material to work with, having a much lower melting point than most metals; it can become liquid with only the heat produced by hob burners. Commercially available moulds and silicone moulding materials make it easy for hobbyists to create their own two-part moulds, allowing them to reproduce pre-existing miniatures or create their own.
Make a proof of your figure from polymer clay. Bake the polymer clay proof, following the included instructions, until it is hardened and set it aside to cool.
Place the working base of the moulding kit on your work surface. Set the mould frame on top of it, using bolts to secure it in place if they are included. If not, use spring or bar clamps to hold the mould frame down to the work surface.
Mix an amount of moulding putty large enough to half fill the moulding frame. Push it into the moulding frame and flatten its top surface. Press the proof you made previously into this surface until it is roughly half submerged in the putty. Push two short (an inch or so) lengths of dowel vertically into the putty until only half of their length is above its surface. These will act as guides to make sure the two halves of the mould line up when you are casting the final figure. Do all of this in the time before the putty begins to set (two to three minutes). Let the half-full mould set for the full time indicated on the putty container.
Mix another equally large batch of moulding putty and fill the mould the rest of the way, laying the flat top-plate over the moulding frame and clamping it down when finished. Let this second half of your two-part mould dry.
Remove the clamps and top plate, then push the completed silicone mould out of the mould frame. Pull the two halves of the mould apart and carefully remove the proof. There should be a cavity that is the exact size and shape of the figure. Determine from what side you will pour the liquid metal in and use a hobby knife to cut a small pour-channel into the inner surface of one of the mould halves. The channel should go from a part of the cavity in which the figure will be formed to the side of the mould you will pour the metal in from. Cut another channel to let air escape. This one should go from the highest point of the model (the vertical direction being defined by the side of the mould into which you will pour the metal) to the outside of the mould. Enlarge the outside end of the pour-channel so that you will be able to fit the end of the funnel into it.
Put the two sections of the mould back together, using the dowels to ensure correct alignment. Clamp the halves together with spring clamps so that they are tightly joined and brace the mould with the pour-channel and air vent upwards so that it will not tilt when being filled. Insert the end of the funnel into the pour-channel.
Break off a chunk of the pewter ingot that looks to be somewhat larger than the volume of the final figure. Place it in a pan on the hob and heat it at high heat until it melts, then for a further 20 minutes. Turn off the stove. Slowly and carefully pour the molten pewter into the funnel until there is no more pewter, or the mould is filled. Leave the mould for a couple of hours to give the pewter time to cool and harden.
Remove the clamps and separate the two halves of the mould. Gently remove the figure with a pair of needle-nose pliers. Remove any excess pewter and the stubs from the pour spout and air vent with the pliers and smooth down any remnants with a file.
You can reproduce already existing figures using the above method in addition to creating your own.
Always be very cautious when handling the molten pewter, as it can cause serious burns and damage furniture if it spills. The pewter may bubble and spit when melting, so use a deep pan or one with a top.