Build a furnace, create custom molds, cast a piece of jewelry, then mount a custom cut stone

Step 3 Make molds

The molds are created using a process called lost wax casting. Basically you carve whatever it is you want to be made out of wax. You set it in plaster then melt the wax out leaving a cavity in the shape of whatever you carved. You pour molten metal into this cavity and let it cool, creating a beautiful piece of jewelry. Its a little bit easier said than done but with a little practice becomes relatively easy.

1. I bought a big candle at walmart and melted it down with my blowtorch into a plastic cup. The candle had a bit of a grainy quality to it that was gone after melting it. Which allowed me to get much more detail when carving and it prevented the wax from 'crumbling'. You can melt the wax into anything that wont melt and you dont mind getting waxy.

2. Carve. There is no real set way to do this. I traced an outline of the piece onto the wax and just free handed it with an exacto knife. The picture of the finished mold is from an earlier design for my piece, after many tries the design evolved into what you see in the first picture.

3. Set the wax in plaster. I used a special microwavable version of plaster called faster plaster that after an hour of curing can be microwaved for a few minutes fully curing it. This isn't necessary but it prevents having towait 24 hours for the plaster to cure and if you invert the mold on a couple wooden blocks (i used jenga blocks) all the wax will cleanly melt out (preferably onto a paper towel) while its in the microwave. I suspended the wax piece by a hanger in the center of the plaster and used a cut off styrofoam cup to hold the plaster. After an hour the plaster is hard enough to remove the hanger and peel off the cup.

Also make do your best to remove any air bubbles from the plaster. Tapping it gently on a table helps remove some, i mixed my plaster using a gillete vibrating razor modified so that it didn't have any blades (basically just a vibrating handle) it worked very well.

*important* you cannot leave the styrofoam cup on the plaster while microwaving because it prevents the water vapor from escaping from the plaster.

4. Admire your awesome mold

Comments

[curvy77]

can soft clay be substituded for plaster or does it have to be baked clay?

[bono80kuriks]

so just to get this correct....... the wire that you taped to your desk in the 5th picture is touching the wax carving so that when the plaster dries there will be a hole that the wax can drain out of. right?

[Toastytoes]

And that you can pour metal into.