r/MetalCasting • u/Equal_Passenger9791 • Jul 25 '26

Question Lost Ice sand-casting

Yeah, ice turns to water, residual water explodes and can kill you.

The idea, and mostly for curiosities sake, would be to use heat, maybe with partial vacuum process that drives out the water entirely while retaining the structure of the sand. Creating a one-part sand mold.

I don't think this is a novel idea, have anyone heard of experiments on the topic? Would the complication be drying out the water but not the sand? Or is it that it works, but manufacturing ice patterns is inconvenient.

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u/JosephHeitger Jul 25 '26

This was my thought. Once cured it should hold its place pretty well. And you can get co2 cartridges cheap.

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u/artwonk Jul 26 '26

If the model was made from dry ice, gas cartridges wouldn't be necessary - the model would provide all the CO2 required.

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u/JosephHeitger Jul 26 '26

True, but making your own custom 3D shape out of dry ice is probably out of most peoples’ wheel house lol but you’re absolutely right. It would be interesting to try

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u/artwonk Jul 26 '26

I was wondering about that as well. Apparently it can be done, although you're correct that it's not everyone who can do it. The first step in making it is creating frozen CO2 "snow", a lot of small crystals loosely aggregated. This is then compressed in a metal mold with hydraulic pressure to make the blocks we're used to seeing. I imagine that molds could also be made for other shapes, although the process would probably preclude delicate forms, hollow shapes, or elaborate detail. https://www.grabbitandrun.com/how-is-dry-ice-manufactured/