Goldman - dude. You doubted me? I'm hurt, man, I really am...
Tahlequah. Welcome to the thread, and thanks for posting

Granted, this info might have been slightly more useful
before I fired my rocks, lol. JK!

Seriously though - I took your info and used my BFFE, google.
GrannyBJ might want to read
THIS , as it is in Potterese - but from what I gather, at the heats I am working at, 400°-500°F, nothing bad is going to happen in the way of gases - and two of the principle ingredients of cement, Silica and alumina, are noted to being fairly resistant to firing.
So on to salt itself, and I found this bit I will quote here, but will post the threads link after for those who want to read the whole thing. Now this is a response to a pottery thread, but since the thing they are talking about is related, I think some common ground can be found between the two.
Without going into details of his exhastive effort his conclusions were that less than 1% of the salt used in a typical firing was actually consumed in sodium combining with silica for glazing effects and the rest was exhausted through the flue and into the atmosphere AS SALT AND WATER VAPOR. The stuff our mothers use on us when we have a sore throat. As for clorine gas, NONE was measured in the stack and HCL production was so small as to be difficult to measure.
THIS LINK
I will stand by my first thought that the caustic fumes are somewhat like a humid/rainy day in the desert. The alkalinity and pH of the rock is picked up by the water I feed the oven with (warmth and moisture) as it wafts through the rock, becoming steam that is released into the air, and thus causing a mild sting to the eyes and throat.
If someone knows where info to the contrary can be found, please post it!
Tahlequah, if you find those books, please do look and post wat you find. But even if the pH isn't any lower, the rock is certainly stronger than it otherwise would be - I've made enough rock to gauge this. I'd say in strength, it is easily as strong as two week old rock.
I am waiting to do my initial pH test until all of this last batch is fired and released - might as well kure it all at once - test results won't be different for having more or less. Tonight will see the last of this batch fired - so by the weekend I should have something solid for you.
