Insulation question: insulate before or after curing?

[Extremedave]

Ready to start firing the curing fires on my brick oven and wanted to know if I should have the dome insulated first or if my first series of fires should be done first and then insulate after? Mortar has cured for about 1 week and everything ready to go but want to know if I can start applying insulation layer now or if I need to wait until curing is done.

I plan to insulate with 1 inch of blanket and then Kastolite refactory moldable insulation on top. Because this top coat will have moisture in it, wanted to know what you think.

Thanks.

[NCMan]

Re: Insulation question: insulate before or after curing?

You may get varied opinions on this issue. I personally think it is better to have the drying fires w/the insulation off and just don't agree w/some others that say to have it on. I understand their logic, just happen to not agree w/it. I think the best advice is to go about the drying process slow and easy to allow the moisture to escape. In the end, it's up to you and I believe lots of builders have done it each way and the pizza didn't seem to mind.

[Laurentius]

Re: Insulation question: insulate before or after curing?

Agreed, start driving out moisture before putting up an insulation barrier, its a long and slow process of getting moisture out of insulation. As the English and Aussies would say, "Give yourself a leg up".

[Lburou]

Re: Insulation question: insulate before or after curing?

I needed some repairs (cracks) before insulation. Glad I waited.

[SableSprings]

Re: Insulation question: insulate before or after curing?

I needed some repairs (cracks) before insulation. Glad I waited.

I also did my curing fires without dome insulation. Didn't have anything but the expected minor cracks...but it was good to have the peace of mind that all was well when I put on my permanent insulation & dome facade/cover. It was also interesting to watch the steam (being released through the minor cracks) gradually diminish during each phase of the curing fires (and then for the last few fires...no steam venting).

[david s]

Re: Insulation question: insulate before or after curing?

As a general rule, if you see steam then you are proceeding too fast. Back off and dry slower. If in doubt about whether there is any moisture left throw some plastic over the oven to see if any moisture condenses on the underside of the plastic.
I'm a fan of doing the drying fires with the insulation on as it helps even out the temperature difference between the inner and outer surfaces of the refractory. This is more important for castable than a brick dome because the castable hasn't been fired, but bricks are already pre-fired, although the mortar in a brick dome has not been pre fired. An uninsulated flue tile is more likely to crack than an insulated one, so logically an uninsulated dome will be subject to the same principle. In the long run I don't think it makes that much difference you can dry it with insulation on or off quite successfully as long as you take it slow. I don't know if Kastolite contains any waterproofing, but if it does it will inhibit the water removal.

[thebigt]

Re: Insulation question: insulate before or after curing?

I put my insulation on but didn't do the wire and render and I have it covered with 3 tarps to keep it dry. Next spring I'll take it off and check for cracks. Most of the people who gave me advice said to do my curing fires with insulation but as NCMan mentioned the opinions will vary