small cracks appearing in the base and dome

[Mae]

This is odd, but just finished insulating 42 inch oven with three inches of blanket covered with chicken wire, and two coats of stucco. The first coat of stucco has reinforcing fibres, but the final coat does not. I have just finished with my curing fires and all looked fine. This morning i noticed a crack in the stucco base, that continues into the fire bricks i used on the deck, and a very fine crack starting at the base of the dome. I seems heat may be escaping out the floor of the oven. The oven floor is firebrick, and I followed the plans when making the base and insulating hearth. Should I worry about this?

[david s]

Re: small cracks appearing in the base and dome

If you did not wait long enough for the outer stucco to dry before firing, that maybe the cause of the cracks, particularly if thestucco coats were thick.Alternatively too much heat too quickly may have caused steam pressure to build up in the insulation space. The outside shell is only a weatherproof covering so it really doesn't matter, although cracks are also places where water can enter, so it's probably advisable to seal up any cracks on the outer shell.

[Phxdt]

Re: small cracks appearing in the base and dome

I wouldn't worry too much. There are plenty of instances where other good builders have observed cracks. They don't hinder the performance too much. Just fill as you can and consider it "character"!