This is a little off topic of the direction the thread is going, but a while back ago folks were talking about the Christian Koch ingot mold. I decided to try one out to see what it’s all about. I’ll be honest, it’s more expensive than I thought it was going to be. You purchase a frame and then have to pay about $200 for every individual ingot shape. I ended up getting the frame and a 4 mm round ingot shape for $325 with shipping. That’s expensive! You could buy 2-3 regular ingot molds with multiple size rod shapes and a sheet shape for that price.
I haven’t had a chance to try it yet, but I’ll report back how it went. Three things that are different from regular ingot molds. They recommend using candle soot as an ingot release. You don’t have to preheat the mold. There’s a fairly wide funnel pouring area, so it should be comparatively easy to get the metal into the hole.
Full disclosure, I didn’t personally pay for this. I bought it through my teaching job. I can’t imagine buying this for myself. But like I said, I wanted to try it out and see if it’s miraculously easier. I’ve got a few students who have a cultural connection to using high karat gold where any mess up is potentially a big one.
We jewelry types are all tool junkies and this looks very nice. However, if I wanted something like this I would go to my local machinist.Two pieces of appropriate sized square bar stock could be trued up flat on one face, then clamped together and drilled out to 4mm or whatever size you wanted. The cone shape on the top looks suspiciously like exactly what you’d get if you used a 45 degree bit used for drilling stock for lathe centers. Might want to drill a couple of holes for bolts to hold it together instead of using a keyway to keep the halves lined up. It wouldn’t have a pretty logo, but I think I could get out for the cost of materials plus 1/2 to 1 hour labor. Of course, I am not using a whizz-bang induction furnace with argon (which this fits into), just my cheap Chinese electric melter…-royjohn
royjohn…I had the same thought the first time that I saw these molds. I am curious about induction melting but can’t figure out why it is so expensive…Rob
Rob (and all)
I think the induction melting they are talking about is those big Nutech and similar vacuum-induction casting machines…so usually you put in the casting flask and then your metal and close the thing up, and it melts the metal and then, at the push of a button, whoosh, the metal goes into the casting flask which is protected by argon or some other inert gas mixture. Evidently, this mold fits into the furnace and you can melt your metal in the furnace and “cast” an ingot which you can then use for fabrication. So you have a high dollar ($10K??) casting machine, but you are using it, in this case, to cast an ingot for hand fabrication. I think that’s right. Not really necessary to have this special shape if you are going to torch melt or use a pour-by-hand electromelt. -royjohn
David from Pepe said that using a torch and crucible with the KC ingot mold is no problem. I made sure to ask that before I bought it. But am happy that you double checked!! Thanks Julie!
I’ll let you know what I think after I give it a try.
keeping the mould hot is crucial. The pour has to be in just one stroke… doing it correctly is very difficult. Two out of three ingots had to be remelted and repoured before I got the hang of it. I used oxyacetylene for melting and a propane air torch on the mould… juggling torches, melting dish was difficult also… using superheat to keep the metal liquid and flowing is also crucial… if either ingot mould or metal or both aren’t hot enough, the pour will not fully fill the mould and leave defects. Not that easy… Could have used a more simple mould than a steel ajustable one, but the steel mould does have holes for rods to make wire. I could not make an igot and a rod at the same pour. Maybe someone else with more experience could comment.
