Curing Concrete and Masonry

[Acoma]

I got the tarp and 5 gallong container Without confirmation, I will proceed with my curing method (Tuesday).

[Frances]

OK, I've got a question for this thread, too:

I put that layer of cement/lime - based render/mortar stuff on my oven on Saturday, got it well covered to stop drying out and was going to refrain from firing the oven for one or two weeks...

But now we've got an unexpected cold front approaching, should hit tomorrow night and go down to -2 C (about 28 F). So should I maybe light a small fire in my oven today in the hope that the heat will work through all the layers and keep the outside above freezing tomorrow night?

Or has the mortar had enough time to harden so a mildish frost won't hurt?

What's worse for curing in this situation, cold from the outside of heat from within?

Any advice will be very welcome!

[Acoma]

What is well covered. In my opinion, if you have warm tarps and blankets on it, you will be above freezing and fine.

[Xabia Jim]

Frances, you would probably only need to put a light bulb on inside your oven to maintain enough warmth to keep it above 32, particularly with the outside covered.

don't lose any sleep.....

[Frances]

A lightbulb on the inside will be enough to keep it above freezing on the outside through all the insulation and whatnot?? I wouldn't have thought the heat would penetrate that far. Whew, those little chaps are more effective than you'd ever guess!

Ah well, I'll put a light in and cover the oven with our picknick blanket (only a tarp so far, Acoma - not very warming, its more to keep miosture in right now). After all, its not going to be all that cold, and there's not much I can do at this stage anyway. It'll be ok. I guess.

Thank you guys!

[david s]

There seems to be some confusion with concrete curing (where we want to keep moisture in) and oven curing where we want to gently eliminate water. It is unfortunate that the same term "curing" is used for the two techniques which are almost opposite in their desired outcomes.

[Xabia Jim]

Ferrocement - Wikipedia, the free encyclopedia

another excerpt : During hardening, the ferrocement is kept moist, to ensure the cement is able to set and harden.

The wall thickness of ferrocement constructions lies in general between 10 and 30 mm. Like other applications of cement, a considerable amount of time may be necessary for the material to fully cure and reach its final strength. Curing time is dependent upon the span or application load, and ferrocement can take a month before it is ready for use.

[Xabia Jim]

Maybe David is right, should we call it "seasoning" our oven?

[david s]

Sounds like we're going to rub it with oil and herbs. But yes, another term would help avoid the confusion.

[Xabia Jim]

Hmmm, I do use rosemary in all my fires....

the first is certainly a chemical cure when you keep concrete and mortar moist for anywhere from a day to a month.

the second is a drying cure for refractory masonry to drive out moisture using a series of increasingly hot fires.

they are really quite different and even oppositional tasks!

Starting the second "cure" too soon can destroy your mortar (not the firebricks) I've done that by building a firepit and starting the fire too soon!

....maybe "refractory seasoning"