How long should i wait before firing my wfo?

[Wheels1974]

I have just covered my WFO with two layers of insulation blanket and I am hoping to cover the dome with the 4 to 5 inches of refractory insulator then the final layer of waterproof render.
I would like to know if there is a time frame I should wait before I beging to start curing the WFO after applying the 4 to 5 inches of refractory insulator and render, or doesn't it really matter?
For what it's worth im using Sheralite which is allot easier to apply then Vermiculite and it's just a later technology version of vermiculite? Although both do the same thing.

I'm not sure if it's worth me writing this extra stuff but I may as well so you have ALL the details.
The ground foundation has been done over 6 months ago.
I done a 4 inch slab of concrete and rio and another 4 inch slab of refractory insulator on top of the concrete one and these were finished about 3 months ago. The dome using fire bricks has been done about a month ago.

Your advice is much appreciated.

Regards
Dean

[nissanneill]

Re: How long should i wait before firing my wfo?

Dean,
get those small fires going ASAP. Get that moisture out of your bricks and then from your insulating layers.
It is easier to evaporate the moisture than passing it through your insulation layer.
Keep them mild and every day even whilst you are still working. It won't get hot, only warm. You can also use a fan especially in this hot spell that we are again experiencing. It will blow in warm air and also remove moist evaporating moisture.

Neill

[SteveP]

Re: How long should i wait before firing my wfo?

I let the mortar cure then fired mine just after I put the insulating blanket on. I put on the perlite/cement layer after the firing and everything worked out just fine.

[david s]

Re: How long should i wait before firing my wfo?

Dean,
I don't know how much vermicrete you've put on, but for every 100L you will have added around 30L of water. It takes an awful lot of energy to evaporate this much water. I think you are better off, if you have the time, to let nature do some of this work for you sun and wind will dry the layer out a lot (maybe not if you live in dismal Melbourne- my old hometown) Leave it for a week or two, unless you're in a hurry. Try the gas burner for curing, it's easier and you have more control. Cure before applying the stucco/render otherwise steam pressure may create cracks in the outer layer.
Cheers,
Dave

[Wheels1974]

Re: How long should i wait before firing my wfo?

Dean,
I don't know how much vermicrete you've put on, but for every 100L you will have added around 30L of water. It takes an awful lot of energy to evaporate this much water. I think you are better off, if you have the time, to let nature do some of this work for you sun and wind will dry the layer out a lot (maybe not if you live in dismal Melbourne- my old hometown) Leave it for a week or two, unless you're in a hurry. Try the gas burner for curing, it's easier and you have more control. Cure before applying the stucco/render otherwise steam pressure may create cracks in the outer layer.
Cheers,
Dave

I'm using a refractory insulator called SHIRALITE its a hell of a lot easier to work with then VERMICULITE. By what you have just described regarding
100L of VERMICULITE you need 30L of WATER that is AMAZING 30% is water. There is no way that this SHIRALITE needs so much water. It is basically like mixing cement except ALL you use is the SHIRALITE and mix it with water.
I purchased 10 20kgs bags so I have 200 kgs or 440 pounds of this SHIRALITE it's fantastic stuff.

Regards
Dean

[david s]

Re: How long should i wait before firing my wfo?

I don't know about shiratite, but the vermiculite granules are full of holes and act like a sponge, so they hold lots of water. Maybe the shirilite doesn't behave in the same way. This may be an advantage for you.