Oven Curing

[Harrison]

Re: Oven Curing

thanks David, ive decided to go with your idea and am splitting the wood to 'wrist thickness' as i go..

finally i completed my curing/firing yesterday. Today i wanted to fire it up to see how hot i can get it. Admittedly i didn't load it too much but had a descent size fire going for about an hour or so... burnt through about 24 logs 2''x3''x16'' each.

only managed to get the internal temp upto 280C... i imagined it would have got alot hotter... any advice on what im doing wrong?

the outside of my oven was only slightly warm to the touch.. and also the top of the chamber(on inside) turns white, which i am told by my elderly italian neighbour it indicates ideal cooking temp

[david s]

Re: Oven Curing

As a general rule I reckon burn nothing thicker than your wrist

[bimbo]

Re: Oven Curing

I just had some firewood delivered (ironbark $65 for quarter ton) and the sizes of the pieces are approx L30cm x W10cm x D15cm. I feel as though they may be a bit too big?? what do you think?

..and because its ironbark, it will take some hard yakka to split them..

I would split some of it down to pieces about 3-5cm round to use to get the fire going. If it is well seasoned it should split ok with an axe

[Harrison]

Re: Oven Curing

cool thanks for the advice. starting the firing today

I just had some firewood delivered (ironbark $65 for quarter ton) and the sizes of the pieces are approx L30cm x W10cm x D15cm. I feel as though they may be a bit too big?? what do you think?

..and because its ironbark, it will take some hard yakka to split them..

[david s]

Re: Oven Curing

The outside render needs at least a week of dampness to increase its strength. Ferro cement boat builders talk about 28 damp days. I would be starting the curing process, but don't rush it. You can cook bread and roasts at 200 C just don't be in a hurry to get to pizza temp.

[Harrison]

Re: Oven Curing

hi guys,

i have finished my oven about 3 weeks ago. i used 1 inch thick high grade refractory mortar as render over the dome, then 2inches if ceramic fibre blanket and finally an inch of cement render (added fire-clay and lime) to finish.

i havent yet started the firing process as i have a concern. The weather down here in Sydney Aus is cold and wet. Over the past 3 weeks, almost half of the days it has been raining. My oven is out in the back yard in the open. would it still be ok to begin the firing process?

regards, Harris.

[MK1]

Re: Oven Curing

Thanks guys. I'm just about to close my 42" in in the next week or so and this is just the information I need. Dino, in particular, thanks for the insight into why your oven cracked, maybe more than the average amount. The gas burner sounds nice and controllable. Thanks for the great method David.

Mark

[Johnny the oven man]

Re: Oven Curing

Charcoal or Heat Beads is still the easiest managable source for dry outs, along with the BBQ gas ring.

[david s]

Re: Oven Curing

Dino,
I agree entirely with your assessment of the curing situation. Because the flame of a wood fire is somewhat difficult to contol the temp is fluctuating wildly. My experience with firing pottery in wood kilns taught me that the cracks in pottery were created from sudden temp changes. Hope this info can help somebody.

[Dino_Pizza]

Re: Oven Curing

I fire cured my oven over the week and if you followed my thread, I got a substantial crack thru 4 rows of brick from the inside to the outside. Cracked thru 2 brick corners too, not just mortar. It's heartbreaking at 1st but it all works out fine. However, here is short (for me) version of how it happened.

HERE IS WHAT I DID WRONG (& what I think you might do right) I did the 100 degree starter fire and increased by 100 deg for 7 days. The 1st day, newspaper only, 2nd day, paper and twigs. Both times I (wrongly-I believe) I kept these fires for a few minutes, got up to the required temp and shut my oven door until the next morning.

Now, a 100 or 200 deg fire, in a large 42" oven for a few minutes basically did little or nothing for curing the oven. On the 3rd day when I went to 300 deg (sometimes hitting close to 400 at the dome peak) it was like my oven got the big heat for the 1st time in the high 300 and that's when it cracked. I can see doing this in a 31" oven might have worked fine, but if you are going with a larger even, I feel (IMHO, just an observation of what I THINK I did wrong) you need to keep those 1st 2 days of temperature at the suggested deg's for 4 hours or more. Enough for the ENTIRE oven to see that temperature. Then, it won't get shocked when you create the bigger fire needed for 300 degrees. This allows for even and well spaced "hairline cracks" for the oven to expand instead of always using the easiest large crack it created in my case. I found the post regarding 300 deg 1st day fire "for as long as you can", "4-6 hours" but did not apply that to the 100 deg/1st fire method which I clearly should have.

Hope this helps, just know that my oven works great in spite of the crack mishap and I know yours would too but best to avoid it. Cheers, Dino

[Johnny the oven man]

Re: Oven Curing

Heat beads do a great job on dryouts, allows you to spread the heat out. Slow dry out is the answer.

[Frances]

Re: Oven Curing

I did mine without a thermometer, its not a problem. Just remember to go slow... start small and make your fire just a bit bigger each day, keeping it burning for as long as is practical.

It probably doesn't matter what exact temp you reach each day, as long as you don't rush things.

[JUBILEE]

Re: Oven Curing

We are ready to start the curing fires in our oven but we don't have a thermometer. i know to start with newspaper, but how much or for how long? we don't want to over do it with the first fire. any suggestions?

[james]

Re: Oven Curing

Agreed. The most important thing is to not go over 300F the first day and 350F the second day. Hold the temperature as long as you can during the first two days. You are essentially trying to slowly bake out all the moisture in your oven, without creating steam.

You oven will have different temperatures and different spots, so look for the temperature in the largest part of the oven. Not directly on the spot where the flame hits the dome, and not the outer reach where the floor meets the dome. Look at the top of the dome, just off where the fire hits.

Hope this helps!
James

[Acoma]

Re: Oven Curing

Mark, several approaches exist. I don't have time right now to look up the details.
1) For a week you progress in heat by 100 degrees starting with 100 until you get to 700 degrees. Each time you obtain this temp you shut the door, keeping the heat inside, and shut down operation until the next day.\
2) Doing a 6-8 hour burn for four to five days.
300
400
500
600
700

You cannot go over these temps, and you must be sure that the heat is consistant throughout the oven. Others will verify my details.