Oven Curing

[That's Amore]

Re: Oven Curing

Ok, so I can actually light a small fire one day and a few days later start again and slowly buid it up until I fell certain that the moister is out then build it up to the 800 deg C. Thanks for the help , just a little scared to scew things up after all the hard work, hate to see it fall apart by doing something stupid.

[fxpose]

Re: Oven Curing

I did not follow a prescribed schedule of any kind. At my convenience I did several casual low temp charcoal burns (about 250F) during the first week and upped the temp the following week by burning wood. You can also just throw a heat lamp in there for the first several days to start.
You just need to make sure that most all moisture is out before you get to the point of building that big scary fire.

[That's Amore]

Re: Oven Curing

Stumpt....with a long enough fire the interior should stabilize and your temp readings will come close to one another.

Could you answer this for me ?? Thanks in advance

James, just wondering why the PDF is different than what you say, I like the way you say get to the temp then let it cool but see the diference

Day 1. Maintain a fire temperature of 300?F throughout the
day and as long as possible into the evening. If you cannot
continually run a 300?F for at least six hours, repeat step 1
for a second day before moving on to Day 2.
Day 2. Repeat at 350?F.
Important Note. While it is difficult to maintain consistent,
low temperature fires, it is critical for proper curing that you
do not go above these temperatures during the first two
days, or a total of 16 hours.
Day 3. Repeat at 400?F.
Day 4. Repeat at 450?F.
Day 5. Repeat at 500?F.
Close the oven door every evening to preserve dryness and
heat.
Enjoy your oven. You have earned it. For additional
information on how to get the most from your Forno Bravo
Casa oven, read our guide to Wood-Fired Cooking,
available on the Forno Bravo CD-ROM provided with this

[That's Amore]

Re: Oven Curing

James, or can anyone answer this, just wondering why the PDF is different than what you say, I like the way you describe the curing getting to the temp then letting it cool but see the diference i quoted from the pomeii PDF

Day 1. Maintain a fire temperature of 300?F throughout the
day and as long as possible into the evening. If you cannot
continually run a 300?F for at least six hours, repeat step 1
for a second day before moving on to Day 2.
Day 2. Repeat at 350?F.
Important Note. While it is difficult to maintain consistent,
low temperature fires, it is critical for proper curing that you
do not go above these temperatures during the first two
days, or a total of 16 hours.
Day 3. Repeat at 400?F.
Day 4. Repeat at 450?F.
Day 5. Repeat at 500?F.
Close the oven door every evening to preserve dryness and
heat.
Enjoy your oven. You have earned it. For additional
information on how to get the most from your Forno Bravo
Casa oven, read our guide to Wood-Fired Cooking,
available on the Forno Bravo CD-ROM provided with this

[That's Amore]

Re: Oven Curing

James, just wondering why the PDF is different than what you say, I like the way you say get to the temp then let it cool but see the diference

Day 1. Maintain a fire temperature of 300?F throughout the
day and as long as possible into the evening. If you cannot
continually run a 300?F for at least six hours, repeat step 1
for a second day before moving on to Day 2.
Day 2. Repeat at 350?F.
Important Note. While it is difficult to maintain consistent,
low temperature fires, it is critical for proper curing that you
do not go above these temperatures during the first two
days, or a total of 16 hours.
Day 3. Repeat at 400?F.
Day 4. Repeat at 450?F.
Day 5. Repeat at 500?F.
Close the oven door every evening to preserve dryness and
heat.
Enjoy your oven. You have earned it. For additional
information on how to get the most from your Forno Bravo
Casa oven, read our guide to Wood-Fired Cooking,
available on the Forno Bravo CD-ROM provided with this

[That's Amore]

Re: Oven Curing

Curing your oven is an important step in the installation of any brick oven -- whether it is a Forno Bravo precast oven, a Forno Bravo Artigiano brick oven, or a Pompeii brick oven. Heating up your oven too fast can lead to cracks. You have invested a great deal of time, money and energy in your oven, so go slow, and cure your oven properly. If at all possible, don't schedule a pizza party the weekend your dome is finished.

After you have installed your oven, there is still a great deal of moisture in the mortars, hearth concrete, vermiculite, and the oven chamber and vent themselves. Each of these oven components was recently produced using an air-drying, water-based process. Simply letting the oven stand for a week does very little to "cure" the moisture out of them oven. In fact, the Forno Bravo precast oven producer recommends letting the oven stand for a week after it has been assmebled before "starting" the curing process. Thicker sections of concrete can take many weeks to cure.

You are trying to avoid two problems. First, any mortar or concrete that dries too fast shrinks and cracks. These cracks can let hot air and/or smoke escape from the oven chamber. Second, if you bring your oven up to heat while there is still sufficient moisture in the oven dome or mortars, you will actually create steam, which can produce hairline fractures, or even cracks in your oven. I heard a story (possibly an urban legend) from one of our installers who used to work with one of our competitor's ovens, where the home owner lit such a large fire in a non-cured oven that a chunck of the oven dome actually blew out the front door. Hmmm. Maybe.

Also, using a space heater can help, but only so far. It is not an alternative to fire curing. We ran a space heater in an assembled Forno Bravo precast oven for two days, then quickly heated the oven up, (don't do this at home -- it was an experiement to see what would happen to an oven that we have here) and we found that we created a very large amount of steam from the oven, mortars and vermiculite, which went on for hours and hours.

To be safe, here is a good curing schedule.

1. Let the oven sit for a week or so after you have finished the dome.
2. Run a series of seven fires, starting with a small, newspaper-only fire.
3. Increase the size of the fire each day by about 100F
200F
300F
400F
500F
600F
700F
800F
4. Let the oven fall back to cool as soon as you reach the temperature you want. It is important to bring the oven up to heat gently, then back down to cold, each time.
5. If you don't have an infrared thermometer, try this schedule:
Newspaper only
Newspaper and a little kindling
1 stick of 2"x3"X16" wood
2 sticks of wood
3 sticks of wood
4 sticks of wood
5 sticks of wood

James

James, just wondering why the PDF is different than what you say, I like the way you say get to the temp then let it cool but see the diference

Day 1. Maintain a fire temperature of 300?F throughout the
day and as long as possible into the evening. If you cannot
continually run a 300?F for at least six hours, repeat step 1
for a second day before moving on to Day 2.
Day 2. Repeat at 350?F.
Important Note. While it is difficult to maintain consistent,
low temperature fires, it is critical for proper curing that you
do not go above these temperatures during the first two
days, or a total of 16 hours.
Day 3. Repeat at 400?F.
Day 4. Repeat at 450?F.
Day 5. Repeat at 500?F.
Close the oven door every evening to preserve dryness and
heat.
Enjoy your oven. You have earned it. For additional
information on how to get the most from your Forno Bravo
Casa oven, read our guide to Wood-Fired Cooking,
available on the Forno Bravo CD-ROM provided with this

[david s]

Re: Oven Curing

Generally the oven curing is a one time thing although after periods of heavy rain and high humidity the oven will pick up quite a lot of moisture and won't work quite as well, you can tell usually because the outside will be hotter than normal. We live in the tropics and can have up to 6" of rain in one downpour and the humidity is oppressive. can't really say how your weather would effect it. Usually a couple of decent firings will get it back to normal again. Not a bad idea to give it a few gentle firings after heavy rain periods before taking it up to max. This simply means do some roasting or baking first.

[That's Amore]

Re: Oven Curing

Hello, I have just finished the 42" pompeii dome on the weekend and am planing to let it sit for a week before I start curing. I have a question, I am from Sudbury Ontario Canada and the temps right now are 9* c for thr high down to 0* and even -1,-2 deg's c, I put a liitle electric heater in the dome at night so that the mortar won't freeze can I still cure the oven in these cold temps; it does and will get colder like in winter we are talking - 25* c. The other question I have is can the oven be used in the winter and does this have to be cured again or is this a one time thing.

[david s]

Re: Oven Curing

Stumpt,
That is exactly right, when the oven still contains moisture it is difficult to get the temp up at the bottom of the oven. This is usually indicated by a black ring around the bottom of the dome on the inside. You just have to keep firing it for longer, but don't get too big a fire going. Also it doesn't hurt to just leave it for a week so the moisture spreads out to the rest of the structure, then go again with more fires.

[fxpose]

Re: Oven Curing

Stumpt....with a long enough fire the interior should stabilize and your temp readings will come close to one another.

[Stumpt]

Re: Oven Curing

Where are you measuring the temperature for these graduated, curing fires? If I measure from the top of the inside of the dome, I am up to 500 degrees. The outside of the top has never been past 135 degrees, the lower parts of the inside of the dome have never been past 220. Should I be measuring from anywhere in particular? I want to get it cured before I insulate so I can repair any large cracks before I insulate and finish it.
Thanks,

[fxpose]

Re: Oven Curing

Glad to hear your brisket turned out well using the Minion method, dhs.
I did a couple of cooks using the Minion method by placing a chimney full of charcoal in a basket and elevating that basket over a couple of firebicks.

What I'd like to do next time is to do a charcoal ring by placing them up against the dome perimeter and light one end. I've done this in the kettle and you also get a very long low temp burn time.

George

[dhs]

Re: Oven Curing

Went for a beef brisket, used the Minion method and just tossed some hickory chunks in the pile with the unburnt charcoal. Turned out very well. Cooked 7 hours reading 200 degrees at the door (instant thermometer reading through a hole in the door). Then an additional few wrapped in tin foil in a standard oven till the internal temp hit 180. Yum! I sort of half a** this and now realized I should have put on more hickory to get a smokier flavor, but still quite good.

The Oven must be drying out - I did notice a difference while curing on Sunday (cooked brisket on Saturday). The oven was up over 250 degrees using the same Minion method instead of holding at 200 the day before. I couldn't read the exact temp because it was off the scale of the thermometer. So far so good - only cracks a couple of small hairlines in the dome above the doorway.

[dhs]

Re: Oven Curing

@fxpose - thanks for verifying it is ok to do

[fxpose]

Re: Oven Curing

fxpose may have been joking(?), but I like the idea of cooking while curing.

Well, I actually did several cooks during the low temperature curing process. I know several other members have done the same here.

George