I'm making a coal forge for blade smithing, one of the simple galvanized tub ones (credit to Tim Lively).
I am also making a kiln out of an old helium tank, and plan on lining it with the same materials.
I have some H.C. Muddox Fire Clay Mortar from Home Depot.
So, my question is, I don't think that this mortar was intended for lining forges, more like for lining fire place bricks and such. Do you think that the original recipe that it suggests for this mortar will work given the high temperatures for a coal forge and a coal kiln?
The directions say: 1 part fire clay mortar, 2 parts cement, 6 parts masons sand
Questions:
1. Would the directions mix above still work for forge lining?
2. What cement type should be used?
3. Do you think there would be much shrinkage? (there was a ton of shrinkage when I tried a 1:1 mortar/sand mix, I'm guessing that the fire clay shrinks a ton by itself as it dries)
Thanks!
-T