Kemo's South Austin Pizza Oven

[Kemo]

Re: Kemo's South Austin Pizza Oven

then i made my first fire on friday afternoon..paper only and then let it all cool down. Then another one in the evening. I then made a few bigger ones the following days. I think I must have made at least 4 small fires on Saturday and at least that many yesterday. I made yet another this morning before I went to work. I do have a few questions.

1. It doesnt seem like the dome is driving off any moisture like Daves. I feel like my fires are fairly big now. like 5 or 6 small sticks about an inch thick. When does it start driving off moisture? Will I see steam?

2. I noticed a couple of cracks here and there and they seem to go like a crack on the windshield. I have one that runs right up the middle in the front and includes the arch! Any worries here? they arent very big at all and if I wasnt looking for them I might not have seen them. The one on the arch troubles me.

3. All of my fires have been INSIDE the oven...do I need to build a fire outside the oven to cure the landing and outer arch? And if so, should I have done that first?

[Acoma]

Re: Kemo's South Austin Pizza Oven

Kemo, what has been the temps during the burns? You haven't mentioned this? This winter graduating class seems to confront these more than not. I wonder, the mortar for warmer temps gets used for the bricks, cooler temps battling the warm fires inside with no insulation around while expansion of brick and heat, wondering?

[asudavew]

Re: Kemo's South Austin Pizza Oven

Barely touching that dome with those fires.

But just keep increasing the size of them slowly .

Unfortunately, for me, my oven cracks increased in size with each larger/hotter fire. Hopefully yours will not do the same.

I really pushed it on my 3rd or 4th fire.

I do wish I would of taken more pics of the cracks so others could see.
I do have one that is very visible on the inside. I will take a picture of that one the next time I fire up the dome.

Slow is best me thinks.
Have fun and take your time.

Nice job so far!


dave

[gjbingham]

Re: Kemo's South Austin Pizza Oven

I wouldn't sweat it too much either. Keep building the fires a bit bigger each time. Small cracks sound like they are going to happen regardless of what you do. Drastic temp changes should be avoided. Consider pre-warming the oven?

Once I the hair on my hands, eyebrows, and forehead started to singe (sp?) while blowing on the fire, that was when the real steam started working out of the dome.

George

[Kemo]

Re: Kemo's South Austin Pizza Oven

Kemo, what has been the temps during the burns?

looking for a lazer thermometer as we speak

[Kemo]

Re: Kemo's South Austin Pizza Oven

Unfortunately, for me, my oven cracks increased in size with each larger/hotter fire. Hopefully yours will not do the same.

I was thinking the other day at work about the cracks and whats really going on. After covering with blanket and then vermiculite, is it really going to be an issue? I mean, whats going to happen? I would think the smoke would find its way out the front rather than the crack-insulation-vermiculite. After all, smoke isnt rust - thank goodness

[Kemo]

Re: Kemo's South Austin Pizza Oven

Small cracks sound like they are going to happen regardless of what you do.

I have reached an agreement with the cracks. as long as they dont bring down the dome, they can stay

[Frances]

Re: Kemo's South Austin Pizza Oven

That sounds good: Be kind to your cracks and they will be kind to you.

Just as long as they don't invite all of their friends to stay...

[asudavew]

Re: Kemo's South Austin Pizza Oven

Here is a copy of Jim's post on Matrilite. And a link to the thread.

"The most interesting part of the meeting came when he introduced me to Matrilite 18, a product I'd never heard about. It's "a lighweight insulating castable designed for general purpose duty at moderate operating temperatures. Common applications include air heaters, combustion chambers of indirectly fired dryers and door linings. Matrilite 18 can also be used as backup for dense refractory furnace roofs, marine and stationary boilers." Well, moderate, for those guys; see below.

The maximum exposed use temperature is 815 C, while the maximum backup use temperature is 982 C (note this is in centigrade). According to him, this product would be a far more efficient insulator than the perlite/vermiculite Portland mix we've all used because Portland reduces the insulating properties of the dry material, and the dry material itself is not that good an insulator by comparison. After heating to 815 C, Matrilite has a thermal conductivity of 1.53 Btu-in/hr-ft 2-F. The cold crush strength after after the same heating is 1080 psi.

The major components are 39 percent CaO and 35 percent Si02. There are much smaller percentages of other materials, none of which means anything to me.

Right now, it looks like a 25 lb bag will cost about $25 CDN, but I'm not sure just yet. This stuff is light, so the bag is large. Seems to me that this would be the perfect material for coating Insulfrax batts or directly on brick. The rep told me that 2 inches of Matrilite would be far better than 4 inches of vermic/Portland.

The US distributor is Allied Mineral Products, 3025 Mineral Loop, Brownsville, Texas, 1-614-878-0244. No doubt there's a website; this is a multinational company.

In Ontario, the dealer is Alphatherm Inc., 8201 Keele Street, Unit 4, Concord, Ontario L4K 1Z4, 1-905-738-0126, Welcome to Alphatherm Inc. - About Us.

I was given a complimentary bag of Matrilite, and I'll be mixing up a small batch in the next few days and report on performance. Of course, I'm in no way connected to any of these companies, and I can only speculate on performance until I've tried it. If it works, it's just in time because I have three and possibly four FB oven installations to do in the coming weeks. I was told that with two inches of batt insulation and two inches of Matrilite, the need for loose material to fill the enclosure would be eliminated. We'll see."


http://www.fornobravo.com/forum/f28/...ight=Matrilite

I hope this helps Steve.

Looks like good stuff.

I might try and get my hands on some!


Dave

[Acoma]

Re: Kemo's South Austin Pizza Oven

Dave, I had talked about the insulation thicknesses and types of material planned, this being one of them. This was learned from conversations with Jim. I will be going with 3", 5" at apex. This will be applied over the insulation blanket 2", which will be over the 1" of mortar. Filling void to frame will be loose vermiculite.

[Ken524]

Re: Kemo's South Austin Pizza Oven

looking for a lazer thermometer as we speak

Kemo,

I just ordered mine from Forno Bravo. I did a little bit of shopping around before I ordered it. FB seems to have a reasonable price for the type and temp range of thermometer.

[Kemo]

Re: Kemo's South Austin Pizza Oven

Kemo,

I just ordered mine from Forno Bravo. I did a little bit of shopping around before I ordered it. FB seems to have a reasonable price for the type and temp range of thermometer.

I may have to go with the sinjing of the arm hair technique until next pay-day. I hear the hair starts curling about 850 at 3" inside the door

Disclaimer: Dont stick your hands in the oven!

[Kemo]

Re: Kemo's South Austin Pizza Oven

Dave,

thanks for the info...

[Kemo]

Re: Kemo's South Austin Pizza Oven

alrighty! i got my Kaowool Ceramic Blanket - 1" thick 2'x25' roll in the mail yesterday. I wrapped the dome and lined the arch where the chimney transition plate is and made a nice fire. Man, just laying the blanket on the dome made a huge difference in the heat. I didnt get to white hot and I still dont have a thermometer, but... It got pretty damn hot pretty damn fast. I split for about 45min after starting the fire to get a Christmas tree. by the time i got back the fire had gone out to coals but was still really hot. AND - i finally noticed some moisture on the dome under the blanket. So...i have a new theory. Cure the oven under the blanket only, if you get any major cracks fixit, then move on to the vermiculite concrete. this is a nice compromise to my question of wheather to cure before or after insulating. Pics below...

[asudavew]

Re: Kemo's South Austin Pizza Oven

. Man, just laying the blanket on the dome made a huge difference in the heat. I didnt get to white hot and I still dont have a thermometer, but... It got pretty damn hot pretty damn fast.

Nice fire!

Just wait until you add 4 or 5 inches of verm/perlite.....

Are you gonna do some cooking this weekend?


Dave