Tuesday, July 19, 2011
Brick Oven Building without forms
The mortar mix needs to be sticky enough and the bricks need to be moist by not wet.
Refractory mortar (brand name Heatstop) with a small amount of Portland Cement added fits this bill.
Sponge moistening the bricks as you go provides the bonding moisture without letting the brick slip. I was able to bond nearly vertical bricks by pressing and holding for 15 seconds.
A form supported dome leaves you with hardened mortar and the need to almost climb inside the oven later (not for the claustrophobic) to fill voids.
A formless dome however requires that the dome bricks fit tightly before the mortar is applied and this is aided by accurate cuts of both the wedge angle of the bricks in each 'chain' and what I call the 'skew' or end-view angle.