Hardening Sand

[dela]

Randy,

I know people accidentally harden their sand, but how do I purposely cement SD sand?

I tried putting some SD in a cup and adding vinegar. Didn't harden (or at least not in the time I gave it).

Then I tried putting SD in a cup with limewater. Nothing

Then I tried putting SD in a cup with sodium silicate. That actually congealed into something reasonably hard after I forgot all about it . Have not tested to see if it will stay hard after putting it in water.

I'm looking for ways to sculpt rock-like formations with out having to go to concrete...

Just looking for ways to re-use some of my old sand.

Thanks

Mark

 

[Randy Holmes-Farley]

In vinegar it will dissolve, not clump. Clumping is an odd process that I am not sure that we understand, and I do not know how to tell you to do it. It may be mediated by bacteria, or it may mostly be abiotic precipitation of calcium carbonate.

Others have asked before how to make chemically acceptable structures from CaCO3 sand, and I have not had any sort of recipe to provide.

 

[dela]

Hmmm. OK, I'll keep experimenting.

 

[moumda]

Try tile grout instead of concrete. Not sure what type to get but doesn't have the metals that concrete can have.