Experimental Home-Made Refractory

[Donkey]

Kiko Denzer, the author of the 'Hand Made Earth Ovens' book has just posted this experiment at his website.
If you are interested in this sort of thing (which I assume you are since you're here), I HIGHLY recommend his books. (you can get them directly from him on his site)

www.handprintpress.com/books/wood-fired-earth-ovens-experiments-in-diy-firebrick-aka-castable-refractory

[ronyon]

He talks about getting water glass for $9 bucks a gallon! At that price it's clay, rockwool fibers and water glass for the win!

[Deleted]

Water glass serves as liquifier in castables.
One can get the other effects with a very small amount of cement even cheaper.
At high moisture content water glass may cause spalling if heatet similar to cement.
Sodium silicate disintegrates over time.
Potassium silicate is stable.

[ronyon]

Karl, do you mean Portland cement when you say water glass Is comprable to cement?

[Deleted]

Jan 1, 2014 8:54:19 GMT -8 ronyon said:

Karl, do you mean Portland cement when you say water glass Is comprable to cement?

Small amounts of any kind of cement can lower schrinkge of clay
and let it dry faster.

However water class is a great binder for vermiculite and perlite
and cannot be replaced with cement there.