Experiment: Making Sodium Silicate Sand Cores

One of the options for producing sand cores (used to create cavities in cast pieces) is to mix the sand with sodium silicate (“water glass”), and then expose it to carbon dioxide gas, which hardens the piece enough to stand up to liquid bronze. No fire in this video, just a short materials experiment.
#bronze #metalcasting #bronzecasting #foundry #metalwork #waterglass #sodiumsilicate #bronzeage #sandcores #casting

[@joanmajoor3392]

if you have a bottle of CO2 most probably it is compressed to a liquid ( about 60 bars) so always use them upright to avoid the liquid coming out one only needs the gas. If the flow is too high the expansion will cool it down so beware of frost bite

[@ctpctp]

But what percentage Sodium Silicate is your solution there?

[@rickhalverson2252]

CO2 is heavier than air... maybe it would be better to stand the bag up? The co2 stays on the part, air rises.

[@OgmiosForge]

Makes sense to me!