Overloaded oven in start up?

[mbarrett5076]

I think i really messed up. 1 meter diameter oven.

At the end of the previous pizza session I loaded the oven with the wood for the mext burn and closed the door. The oven was 600+ degrees.

The ultra dried and a bit carbonized logs had a nice ring sound to them vs clunks when I started the next firing.

When i started the burn last night i had 2 large pieces on the side and 4 pieces cross stacked above.

They all caught fire very quickly and completely, typically only the inside of the og burns but this was all the way around.

Doesn't look like any damage other than smoke stain on the outside.... it just cam pouring out the chimney was somple overwhelmed.

Am I the only newbie to di this?

[RandyJ]

I believe you made your own charcoal. As long as your oven is cured it should be just fine. They all have smoke stains after a while.

[SableSprings]

I think i really messed up. 1 meter diameter oven. At the end of the previous pizza session I loaded the oven with the wood for the mext burn and closed the door. The oven was 600+ degrees. The ultra dried and a bit carbonized logs had a nice ring sound to them vs clunks when I started the next firing. When i started the burn last night i had 2 large pieces on the side and 4 pieces cross stacked above. They all caught fire very quickly and completely, typically only the inside of the og burns but this was all the way around. Doesn't look like any damage other than smoke stain on the outside.... it just cam pouring out the chimney was somple overwhelmed.

Am I the only newbie to di this?

Do a search in the forum for backdraft (David S has pointed out that the situation that can create a potentially dangerous backdraft in our WFOs is known as a reducing fire in pottery kilns). Several threads have pertinent posts. I've included a link below to a post I made back in 2013 regarding this issue.

https://community.fornobravo.com/forum/brick-oven-cooking/get-cooking/17806-roasting-a-turkey?p=232284#post232284

You can definitely choke out a fire or coals if you have a tight fitting door. And, yes you can produce charcoal this way... However, if you put too much wood in an oven that's too hot and then choke down the air supply, the heated wood will fill the chamber with flammable gases. When oxygen is then introduced by opening your fire door, these gases may spontaneously (and explosively) ignite. That's why the fire department cuts openings in roofs when battling house fires...they are venting those gases out as much as possible before opening doors to the enclosed areas. The movie Backdraft was based on this dangerous situation often faced by fire crews.

The oven's dome structure is very stable and strong. It is unlikely that you would cause damage to the oven, but my own personal experience is that the door may blow back at you and there can be a pretty intense "fireball" that exits the oven ... which might reduce the amount of your facial hair and certainly might call for you to change your underwear in the near future.

If you have wood in the damped down oven and see puffs of white smoke coming out the chimney...you very likely have built up flammable gases in your oven chamber. After making a charged water hose or extinguisher available and removing "potential fuels" from the area in front of the oven, your options are:

1) Recommended...leave it alone and as (if) it cools down and the minimal air supply finally vents out the gasses, you'll be left with a batch of activated charcoal (and some valuable experience).

2) Not recommended...brace yourself, head down, and slightly/slowly increase the door opening. Most likely, as the oxygen increases, the gases will go whuuump and ignite. You'll have a pretty good fire blazing in the oven for a while, so leave the door open enough to keep the fire active until it burns down to less scary proportions.

I usually don't put my wood prep load in the oven (to dry for the next firing) until the oven chamber is less than 250F (a little lower than some others may suggest...cause I've had two of these backdrafts and I won't set myself up for a third ). That said, you're only drying off some minor moisture that absorbed by the wood from the air or a brief shower...you should not be using the oven to dry out uncured/wet wood. Also don't forget that you need to provide moisture an exit from the oven chamber, so leave the fire door open enough for air to circulate.

Sorry for the long, winded diatribe...but your safety is an issue here.

[mbarrett5076]

Thanks. For my next experiment..... loaded it up before reading your post. Will let it back to ambient before opening the door. And yes my oven is effectively air tight now.

neighbor has a green egg and watched him snuff a fat drippings flare up by closing the lid.... only to have a 10 foot fireball and a new hair style when he opened it.

[mbarrett5076]

Update- let the oven get back to 200 degrees - took a couple of days. Very happy w/ the heat retention. Logs came out in 2 color stages primarily - the logs on top - black and what I would call VERY large chunk charcoal, others where deep chocolate brown.

Weight is very light compared to a similar size piece of seasoned firewood.

No more charcoal experiments - other than to do a a planned cook and see how it really handles in bringing the oven up to temperature.

[Lc45]

You might try a simple damper system (vent) in you door such as a series of holes with a sliding cover or as simple as a hole with removable plug.
I have been thinking about using one of these methods or just not making the door as tight, a little concerned about the metal expanding anyway.
My father always made sure the cast iron dampers in fire places floated so expansion could take place not sure if they get as hot as a pizza oven.
wondering about a wood and metal door not sure which way to go yet