Oven Curing

[Johnny the oven man]

Re: Oven Curing

What brand of kiln David, most likely "Tetlow"?

[david s]

Re: Oven Curing

Yes, it's a Tetlow. It has a fancy emissions extraction system which draws from the bottom and then pumps it out through the roof. Some nasty fumes not particularly good for children.

[Wesleckner]

Re: Oven Curing

I finished my oven and have been waiting for a month for a few days of dry weather.

Attached is first curing fire, The top of the dome heated up to 300-350 degrees F, the middle sides only heated to 180 range. I burned a small fire for 8 hours using twigs of oak and branch pieces about 1-2 inches in diameter. After about 3 hours I started seeing black build up on the dome and work its way down, but after 8 hours the it has not reached the bottom 2 courses. It looks to me that the moisture is being removed from the top down which is good.

I am worried that it is going to rain on day 4 of the curing process. Is it a good idea to still light a fire and attempt to cure the oven or will I be waisting my time or damage the oven?

When I get the curing fires up to 400-500 F range can I safely us it to cook with, even though I have not finished curing. I want to roast a chicken or turkey.

[SCChris]

Re: Oven Curing

I'd want to make sure that the oven is covered from the rain but if it's covered curing wouldn't cause problems. The fire will burn a bit slower due to the humidity but it's still going to help. As for cooking, cook away during the curing.

Chris

[Wesleckner]

Re: Oven Curing

Thanks for the info Chris.

It rained last night and I did cover the dome only had the vent stack exposed. I had the oven dome up to 450 F and the outside has cold, the 3" of insulating blankets sure keeps the outside of the oven cool to the touch. The oven stayed dry and was still hot this morning only lost about 70 degrees F in 12 hours. I am going to heat it up to 450 F for a few hours and put a turkey in and see what happens.

Wes

[david s]

Re: Oven Curing

Weslenker,
By the look of the photo you have already done the outer shell. It is better to do the drying fires before making the outer shell so the water can safely find its way out. You will have to take it slow to avoid damage as the outer shell has a tendency to lock the moisture in, particularly if you made it waterproof.

[Wesleckner]

Re: Oven Curing

Thanks for the information, I am going to do a few extra fires in the 450 range for a few more days. I got lucky and it did not rain today! Heated the oven to 450 for 4 hours let the fire die down for 2 hours and cooked a turkey in it at 375 for 3 1/2 hours turned out great.

[gtofani]

Re: Oven Curing

My dome has been done for 4 weeks now and the vent arch area for 3 weeks.
I already have the insulation and enclosure in place. I had the oven up to
100' at the top of the dome using a shoplight only.
I want to get started with the curing fire sequense, I am really worried about the dome cracking since it was a lot of work. I figure the longer I wait the less chance of a crack but after three week since completion of the outter arch and vent area and four weeks on the dome, I am getting anxious to get it fired up.
If a crack does show up, am I supposed to grind out the crack area and remortar it or just leave it alone?

[SCChris]

Re: Oven Curing

Gino, crack repair depends on how big and where it is. If doesn’t or it’s not going to cause future problems and it isn’t unsightly don’t screw with it. When you start grinding you risk creating other problems. As for this stage of your curing you want as even and predictable a burn as you can get. Your mantra should be low and slow, just edging up the temps so that the oven is as evenly heated as possible to the targeted temps.

Chris

[Johnny the oven man]

Re: Oven Curing

BBQ burner ring and LPG is a great curing aid, or use heat-beads.

[SCChris]

Re: Oven Curing

The U.S. translation for Heat beads is charcoal briquettes.

I used a weed burner and LP gas, but as you'll soon hear, many around here consider this method very dangerous and this not recommended by the FB community.

The briquette method is predictable and safe just a bit messy. If you go with the briquettes, consider raising the bed of briquettes above the floor with a grill. This will allow you to get rid of the ash and get oxygen to the fuel. You're going to go through a few bags before you move into burning wood somewhere over 300F. The wood fire is going to be a more dynamic fire that heats faster than you'll expect.

As the oven dries, you will find that the amount of fuel required to heat a set number of degrees will decrease. This will likely surprise you with a burn or two pushing the oven to a higher than intended temp. It'll be ok as long as you know to build your fires slower than you'd like by waiting to add fuel.

I think where people get in trouble curing is almost always due to pushing the temps up faster than they should. Long low slow burns starts the water moving out of the oven and keeps it moving out.

Chris

[gtofani]

Re: Oven Curing

Thanks, thats all very helpful information. I never heard of charcoal called beads, you learn something new every day.

[david s]

Re: Oven Curing

Throw some plastic sheet over your oven when you think it is dry. If moisture gathers on the underside of the plastic you know it's not dry.

[gtofani]

Re: Oven Curing

The dome is already under roof with cement board on the walls so I dont think that will work for me. I think I will go with using a forgers torch to cure it, seems like you can control the heat better than a fire. Thanks for your suggestions.

[david s]

Re: Oven Curing

If yours is an enclosure and you added the insulation loose, you probably have less to worry about. But if you added cement and water to perlite or vermiculite then you will have added a huge amount of water that will take a long time to remove. i can't talk about the use of gas, as it has been banned on this forum, but you can re read the entire "curing" thread to help you.