Is it time to "cure" yet?

[firepie]

Over the weekend I finished up the 6" insulating concrete (vermiculite & portland cement) over the insulating blanket (insulfrax) which is over the brick dome. It's actually looking like a small igloo. Anyway, my next step (I think) is to apply a weatherproof stucco

But, should I "cure" the oven first?

I'm concerned that the stucco might keep moisture in as well as keeping it out, so curing it after the stucco is applied might present a problem.

So what does everyone think?

Tom

[jengineer]

I am assuming you have headed over to the subsection "Firing Your Oven"

If not hit this thread - by the way try to end this thread and do followups under Firign Your Oven

http://www.fornobravo.com/forum/showthread.php?t=767

Concrete needs natural time to cure. Your slab and hearth won't reach a respectable strength until after 7 to 14 days. Generally concrete has most of its strngth anywhere from 28 to 90 days. It depends on the thickness, type, slump and a myraiad of variables including the exothrmic process (throwing off heat). Curing is a chemical process and if you have if occurs too fast as James said your concrete will crack, also if is does not stay damp enough it will crack.

Pulling from one source "While setting, the concrete gains hardness and srength, as the process of hydration slowly permeates the entire body of material, and new chemical bonds extend their fingers throughout the structure. Curing should be allowed to progress for several days before subjecting the new concrete to significant stress. The rate of curing depends on the temperature (as the rates of all chemical reactions are dependent on temperature), and for this reason the "safe curing time" is less in hot weather than in cold, and generally less in tropical climates than in higher latitudes. In the same way that curing concrete should be prevented from drying, it should also be protected from extreme cold. If you have an option, it's better to work with concrete in warm, humid weather than in cold, windy, dry weather."

So lets get an answer. Let it cool down for at least a week , water it slightly to keep it somewhat moist as it cures. Find other yard work to do for another week and then start the fires as proscribed by the link above

je

[james]

If you are happy to cure your oven before doing the final stucco coat, it will make it easier to fully cure the oven and insulation -- and give the moisture somewhere to go.
James

[arevalo53anos]

Tom:



I was baking by two or three months before the isolation was in place.

IMHO I think that you oven could be cured after each step.

Dome closed, light fires. Cladding in place, light fires and next some pizzas.

Do not forget that fired wood discharge moisture, too.

You would like to have a little space free of stucco to let this moisture to go out.



Luis