Although expensive for serial production, cast lead pieces can really make prototypes desirable and delightful to play. Lead casting allows for subtle details, and its weigth feels good. I have just made about 40 lead airplanes, and thought I'd share the know-how.
You will need:
- Plaster (aka gypsum)
- A master object (either off the shelf or you can make yours of wood etc)
- Oil: I use gun oil that comes in a spray can, but motor oil or even cooking oil will do
- Lead.
Where to get lead? One obvious choice is the local angler's (fisherman's) shop. It's not the cheapest source, but a 100 g chunk of lead is a lot, enough for about 30 figures (size ~3 cm). Scrap metal dealers will also have lead, it is still used in plumbing. This might require thorough cleaning. The best source, however, is your tire shop. They use a special lead alloy to balance wheels. Chips of this alloy are clipped onto the rim. This material is composed of lead and antimony (maybe zinc too), and its very similar to the alloy once used in printing, namely for typecasting. It is as easy to melt as lead, but much harder and more rigid when set.
Now take a small box, preferably plastic. I use small margarine pots. Mix plaster with water until it is creamy. Stir well to get rid of bubbles, and quickly pour it into the box until its half full. Take your master object, spray with oil, wipe excess oil. You need to act quickly because plaster sets in a few minutes. Put the piece into the plaster so that half of it sticks out. Position it so that you can get it out later (no extrusions under the plaster!).
Let the plaster set for a few hours. When hard, carefully retrieve the master, use a clip if needed. Oil was needed to keep the plaster from sticking to it.
Now mix in the second dose of plaster. Master goes back to the mould. Spray with oil, this time the half-mould also. Pour plaster onto it, let it set overnight.
Now take it apart, retrieve the master. You will need to carve a groove into the mould, that's where lead will be cast into it. Use a nail to start, then file it. It should be about 3 mm wide. A thinner groove will be clogged when casting.
It is advisable to carve a second, thin groove with a separate exit, to allow air to escape.
Your mould is ready, but probably needs more time to dry. A wet mould might be dangerous as boiling water may throw hot lead back up.
Heat lead in a spoon or a small metal vessel. A tin can will do, but make a "beak" to it to be able to aim with melt lead. Assemble the mould, and tighten it with a rubber band. Pour in the hot lead.
The first few pieces will never be good. Lead sets too quickly when the mould is cold. You might heat it with a lighter, or just continue casting. Wear eye protection in case the metal splutters back - although its heavy so it doesn't fly high.
Have a pair of pliers ready to cut excess metal off. The models will need some filing and grating, especially as the plaster mould wears out, but the result is worth it.
Never thought of that possibility! Oh my God, I have advocated CHEMICAL WARFARE! Hundreds of children will perish by touching lead, thus burning to death.
No Sir, you're mistaking it for plutonium or cesium or something. Lead is not radioactive, touching it will not shorten your life. There are those people, anglers you know, trying to catch fish with rods. They touch lead every day, and they are still healthier than those who don't.
EATING lead might be harmful, but well, I think someone over the age of three can resist the temptation. It's your choice. With all the sulfides and oxides your beloved car exhales, it cannot be avoided. So OK, to be on the safe side, a disclaimer for the above: DO NOT EAT LEAD figures. Play with them.
Oh yes, and as I stated, it is for prototypes. You'll paint and coat them so players aren't going to get in contact with the dreaded LEAD, anyways.