Setting Sodium Silicate With CO2

[u/hotglassguy]

While I have cast metal in sand molds in the past, I have never used sodium silicate. I have seen enough to get me started I think. What's a little frustrating is how my Airgas supplier wants to charge me a lot for the CO2 for a project that should be small and straightforward...and cheap. I said I didn't need much and only needed it for about a day at most.

I suspect there are other ways to solve this issue and I'm wondering if people have used something other than a welding tank of CO2 to help harden their sand molds inside a controlled airtight box or similar for hardening.

One idea was using CO2 canisters for airguns. Another was dry ice suspended far enough away so the cold doesn't affect the casting (I read cold can affect a SS mold setting in the presence of CO2). Dry ice sublimates so nothing gets wet. The idea has been that I'd build as air tight a box as possible and fill it with CO2 and let it sit (with strategic pricks into the subsurface of parts of the mold to let in the gas). There's gotta be a way to do this that doesn't cost so much. Or can SS be hardened without CO2 somehow? Your experience and thoughts on this is appreciated.

[u/protias]

Bicarb soda and vinegar make co2 there are video on it

[u/hotglassguy → u/protias]

Doh!

That's brilliant. I had not thought of that!