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

Step 4 Casting

1. Setup - you want your mold hot and ready to accept the metal, it needs to be hot so it doesn't fracture when receiving the ultra hot metal. It also keeps the metal hot longer thereby flowing better which in turn gives your piece more detail. I used a camp stove which produced a ring of fire almost perfectly the diameter of the mold. You could build a fire if you were outside or possibly heat it up with another blowtorch if you had one (you cant use the one for your furnace)

2. Let the furnace heat up for a few minutes, make sure you have the brick on top to keep the heat from escaping. You want the crucible in the furnace.

3. Put your metal in the crucible and lower it into the furnace. Replace the brick.

4. After waiting a few minutes take the brick off and check the metal, if its red hot and molten then its ok to pour.

5. Quickly but carefully pull it out using pliers on the edge of the wire crucible holder. Bring it over to the mold and pour.

6. Slowly remove heat from the mold and let it cool for at least an hour before touching.

7. You could possibly pop the metal casting out of the mold but i found it easier just to break the mold.

8. Inspect your piece, if it didnt work the way you wanted try to figure out why not (was there air bubbles etc...) and try again. I had to do at least 10 castings before i got the results I wanted. (although i didnt have a sweet guide like this to follow)

9. Next step finishing!

Comments

[AustinMiniMan]

Hi, Was wondering...what silver were you melting? I was hoping to use coin silver, which is 90% Silver, 10% copper. Would you be able to melt that in this forge? Also, if you could melt it, why wouldn't the crucible, being copper, melt?

[seabeepirate]

I think I'll be building one of these this weekend. The first practical item I wanted to make is an adapter from my CO2 tank to my welder. Without the centrifuge could I cast, say aluminum, and get the detail of the threads on the tank or will I have to make the hole smaller and thread it after casting? I'm trying to avoid spending $100 on the adapter if I can.

[Thoth]

Better off casting slightly larger and then using a tap and die set (if you don't own one rent or borrow or just buy one) to cut the the threads.

[swighton]

I think it is unlikely that you would be able to attain the detail of the threads without a centrifuge. If it was an extremely coarse thread you might possibly (I repeat POSSIBLY) be able to cast it with the "thread" part of the thread slightly wider than it needs to be, then file it to shape. The other worrisome thing would be surface finish of the seals. It might require a bit of finish machining on the o-ring seats to attain a good seal.