So like many I'm new at this whole forge making thing- I've made a charcoal forge but its not that great and its a pain to set-up and clean-up so I'm working on a propane forge. I am using the per lite and sodium silicate mixture everyone's talking about but when I tried to heat my forge the smallest amount of heat made the sodium silicate bubble up. The bubbling is white, rocky, and strangely enough kinda looks like perlite (if perlite was a mold). To make sure it was the sodium silicate I put some one a piece of wood and after it was hard I blow-torched it. The same thing happened, white, rocky, hard bubbles. The sodium silicate that I have I bought disguised as Cement Sealer because it was cheaper. I bought a Gallon for $50 and it claimed to be 100% sodium silicate. Whats wrong with it? Has this ever happened to anyone else? Here's a picture. I covered the perlite mixture with the refractory cement from CLKindred's forge making video. This Dark Grey cement lets you see the bubbling effect clearer. What in the world is that?