Oven Curing

[fremen325]

I took a few days off from my firing/curing schedule. My last burn saw a peak temp at the dome of 800F and about 1/3 from the top a steady reading of 450F (1/3 from the top is what I am using as my reference point). Dome still hasnt gone white which I thought it did at 800F. I have some cracks on the outside though I am considering them to be minor. I am still debating whether to grind them out and put some Heat Stop mortar in them before covering with ceramic fiber blanket insulation.

[George_M]

It's my time to start curing fires.
I will wait 10 days before start the first fire.
I need your opinion about the ceramic blanket.
When must i put it on my oven to avoid the moisture to keep it in.
If i start some small fires without the ceramic blanket is it good?

[George_M]

Any ideas?

[JRPizza]

George, there are lots of posts on the forum discussing this.
There are 3 schools of thought - cure without insulation, start with small fires to drive out some moisture but wait to get it real hot till the insulation is on, and don't have any fires till the blanket is installed.
I cured my oven without insulation and did get a crack at the back that may have been caused by uneven heating. I might have waited till I had my insulation on, but was impatient and with the location of my oven didn't feel like I could temporarily place insulation without it being blown off by the wind. I also was in a hurry to cook that first meal in the oven, but was surprised at how fast the oven will cool off without insulation. If I had it to do over I might go for the middle ground option of small fires to start the process and bigger fires after insulating. Like most things with building an oven, you just need to read some opinions and decide what is best for you.

[Amusinglisa]

OK. D.A.Q.: My oven was started last June (2016). It was completed up to the third row of bricks on the dome and stood for a year (in the weather - eek). I have now completed the dome and will finish the outer arch, etc this weekend. Is there a need for the week-long wait before curing fires?

[Dwatkins]

A question was raised on post #20 that I did not see answered. I have the same question, can I begin the curing process once the dome is complete and prior to covering with the insul blanket?

[david s]

There are pros and cons for both methods.
Curing without insulation allows water to escape more quickly and lets you inspect the outer surface of the dome for any tell tale cracks. But it also places much more stress on the structure because there is a big difference in the inside and outside surfaces of the oven walls. This condition is what leads to the failure of uninsulated chimneys and flue tiles, so also applies to uninsulated domes. In addition the top of the oven will dry out way faster than the base leading to a big temperature and resulting expansion difference.
For these reasons I prefer to insulate before doing the drying fires. The downside is that the moisture being pushed out will pass into the insulation layer and take longer to escape.

[Dwatkins]

Thanks for the feedback David.

[andrewe]

Hi all, finishing the dome pretty soon. Thinking about curing. The curing schedule according to the fornobravo PDF is a 5 day schedule starting at 300 going to 500 in 50 degree increments. Does this mean it's safe to start at 300? If so, would I be able to knock one day off the suggested schedule in this thread in order to get to making pizza's a little quicker?

Is there an alternative schedule for less days that I should be looking at, has anyone gone for a shorter cure schedule, is it worth any potential risks to do it this way ?

Thanks!

[UtahBeehiver]

A slow cure is one of the most important factors in the build. This is were we see a lot of builders get impatient and fire too hot, too quick, and cracking or damaging their ovens after all that hard work they put into it. You do not stay what stage of the dome you are at, bare dome, insulated dome, or insulated and final coat. It would be best if the dome is insulated and not stuccoed or final outside coating on. Insulation allow less thermal difference between inside and outside of dome less the thermal stresses. Start with some briquettes (cook something in a dutch oven) that will get you around 200 F, then "SMALL" fires, one extra log can really spike the temp. If you are see steam off the dome then you are too hot.

[andrewe]

A slow cure is one of the most important factors in the build. This is were we see a lot of builders get impatient and fire too hot, too quick, and cracking or damaging their ovens after all that hard work they put into it. You do not stay what stage of the dome you are at, bare dome, insulated dome, or insulated and final coat. It would be best if the dome is insulated and not stuccoed or final outside coating on. Insulation allow less thermal difference between inside and outside of dome less the thermal stresses. Start with some briquettes (cook something in a dutch oven) that will get you around 200 F, then "SMALL" fires, one extra log can really spike the temp. If you are see steam off the dome then you are too hot.

I’m on the bare dome. I plan to insulate it before curing. I will not be stuccoing, but instead will be doing a gabled house structure. So, do you suggest not following the forno bravo schedule? To clarify it says to start at 300 while this thread says otherwise.

[UtahBeehiver]

What I am saying go slow and you can start with briquettes. The original post was asking if you can shorten the cure cycle.

[andrewe]

What I am saying go slow and you can start with briquettes. The original post was asking if you can shorten the cure cycle.

I guess what I’m trying to clarify is two things. Is there a safe way to do a cure cycle that is not a week long (5-6 days)? If not you suggest starting with briquettes and incrementing temperature how much per day?

Thanks for the help so far. I appreciate it.

[Celine]

Hi all,

Today we made the first fire in our oven and messed up big time, I think due to being overly entusiastic. The first fire went up to probably around 570F. During this a crack appeared running from the front door over the dome to the back. It's not very wide, few milimeters, and seems to be interupted with parts that didn't crack.
We of course feel horrible (and stupid) and are wondering now what to do. Should we take the whole dome down and start again or is there a way to kind of fix it with mortar?

Any advise would be great...

[Celine]