High Heat Mortar Mix question

[Frenchcanuck]

Hello, I have conflicting formulas (by different dealers/people etc..)
One mix is thi:
1 part cement, i part fireclay
another is:
1 part cement, 1 part fireclay, 10-12 parts sand

Seems like an awful big difference in mixes, or is it just me???

[nissanneill]

Hi Frenchcanuck
I have almost finished my Pompeii, only the final mosaic tiling to complete and I used a well tried and proven mix for my firebrick mortar, as 3 parts brick layers sand, 1 part hydrated lime, 1 part fireclay and 1 part portland cement.
I have used it for 4 large cookups and no sign of problems.
I certainly would NOT USE either of the formulas that you mentioned.
I would recommend using a brickie sand rather than a washed concrete or plaster sand, but I don't know what you have vailable in your district.

Hope this helps. I have a full pictorial build and explanation in the 'Brick oven photos' forum if you want to follow my construction.

All the best with yours.

Neill

[Dutchoven]

I concur with Neill. That is the exact formula I used for the barrel vaulted bread oven I constructed. It was a recipe I got through the grandson of a oven mason in Czechoslovakia. The only alteration I made was on the wall bricks where some people lay dry joints I used straight fireclay mixed with water. Other than that all joints are mortared with that recipe!
Best
Dutch