Curing before final insulation plus rain?

[Abouna]

Our dome has been done for a number of weeks (these threads!), and I'm keen to start curing it. I'll do the 5-7 day method, though it's probably overkill as we've had 90-100 degrees for several weeks here in the Midwest and almost no rain (and the dome has been covered).

My big questions are:

1. Is it worth curing the dome before we do our insulation layer? I've not ordered the fiber blanket yet (can't find a good price!) so we can't start the insulation and stucco.

2. If I cure now and it rains, I assume all the curing will be for naught? Correct?

Cheers.

[SCChris]

Re: Curing before final insulation plus rain?

Abouna,
The 5 to 7 day is just prudent. Order your insulation ASAP and given your local heat and the duration of the heat, if I were in your shoes I'd insulate after hitting 250F at the top of the dome after low long burns, heck you might get close with a high wattage quartz work lamp and a plywood door. That you heat the dome and hold the dome well over ambient will keep the moisture moving OUT... I think insulating the dome helps to even out the heat and stresses and think it's an advantage. Touch your dome during the early curing, does it feel cool or steamy or just hot and dry? Like most everything else about WFOs it's more about feel than about hard science.

Chris

PS get a laser thermometer and watch the outside dome temps at the base mid and top as well as the interior.

[david s]

Re: Curing before final insulation plus rain?

Refractory materials don't like big temperature differences which in turn create different expansion leading to fractures, so firing after insulating is a safer way to go IMO.

[Abouna]

Re: Curing before final insulation plus rain?

OK, well I've fired it twice now, about 200 and somewhere between 300-400 degrees. Absolutley no steam, warm at the top less warm at the sides. Dry as a bone as far as I can tell.

Barring rain, I can't see any moisture coming off this thing after so many weeks of extreme heat here.

I'd have rather insulated first but everyone is getting anxious to make a few pizzas. So I guess we're doing it that way.

Now if I could just get some insulation. Sure wish the home centers carried this stuff.

[SCChris]

Re: Curing before final insulation plus rain?

Abouna, you are correct about rain and curing. You really need to drive the wet out and maintain a dry dome during and after curing. Tarp it, tent it, somehow protect it from rain and or snow..

Chris

[SCChris]

Re: Curing before final insulation plus rain?

Abouna, Depending what your final plans are for the dome, Igloo or ovenhouse, you could use stonewool. This material is commonly used as the insulator behind fireplaces. Ask for Roxul at building supply places. The advantages are, lower cost and availability, the disadvantage when compaired to fiber blankets is the relative lack of flexability. I say relative because the blankets seem to do a far better job of conforming to the dome shape. I used these bats, sometimes called boards, to insulate around the dome. Since I used a ovenhouse I didn't mind that the bats were cut and ripped to fit, and small pieces were stuffed into the gaps. In the end I used the stonewool in direct contact with the dome. I used fiberglass insulation to fill the largest voids in the ovenhouse and filled the rest, covered it all, with loose vermiculite.

Chris

[Abouna]

Re: Curing before final insulation plus rain?

Well now I'm really stuck at ordering the blanket (thanks Chris, I will look into the stonewool).

McGills has a way better price, but theirs is 2" instead of 1". If I order 2 blankets, is 4" going to be overkill? I've a 46" oven and am having a tricky time deciding what to get and how much.

[SCChris]

Re: Curing before final insulation plus rain?

Overkill is always better than underkill. Nothing is worse than regrets in the knowledge that that additional $ could have made a real difference in what and how you cook.

With insulation, you need to not compress but just contain the insulation. Contain the insulation to the extent that it won't move and will fully jacket the dome.

Again, remember that if you go with an ovenhouse you have space to increase the insulation. With an igloo you are constrained.

Chris

PS I'd wrap that oven ASAP and definately before you push the temps further..

[Abouna]

Re: Curing before final insulation plus rain?

Yes, it will be an igloo style.

Looks like McGills is going to be the cheapest by a long shot.

[SCChris]

Re: Curing before final insulation plus rain?

Wrap it and contain it with chicken wire in prep for the stucco.

:-)

Enjoy!

Chris

[Abouna]

Re: Curing before final insulation plus rain?

I'm trying one place in town here that may have rock wool, mineral wool. I am a little nervous though that I might end up with fiberglass which I know is a no-no. The different names used for this stuff doesn't help!

[SCChris]

Re: Curing before final insulation plus rain?

Since your going igloo, I'd stick with the FB style blankets. They'll be easier to form to the dome and thinner against the dome. I'd have to check, but I think the blankets are about 2x the R-Value. Sometimes Mo-Money is Mo-Betta.

Chris

[Neil2]

Re: Curing before final insulation plus rain?

You can always use 4 inches of 12:1 Vermiculite/perlite to portland cement for the insulation.

[Abouna]

Re: Curing before final insulation plus rain?

Went ahead and ordered the blankets from McGills so I guess were going that direction!

Now, does anyone have any tips for stucco in the Midwest?

[SCChris]

Re: Curing before final insulation plus rain?

I've only done flat work, but if you search around you'll find some great work.

Best to you and yours!


Chris