help cracks!!!!!!

[chrispanzer]

HELP!!!!!! I have recently built a igloo style pizza oven. I followed the instructions that i got from the Forno Bravo site. I have, what seem to me, very large cracks in the dome. I did cure it as per the specifications recommended in the directions. The last fire i had was three days ago and I noticed there is now smoke escapeing of the cracks. Then I gave it a coat of heat stop 50 all over the dome. About 1/2" thick. Then I think this is wear i goofed up. I coated the dome with bonding agent and after letting it dry i gave it a finish coat of stucco. What I believe happened and later caused the cracks is that the stucco through expansion and contraction pulled the coating of refractory mortar away from the bricks and caused all the cracks. My question is: Am I squrewed? Please if any one has any input it wold be much appreciated.

thank you
chris

[Les]

Re: help cracks!!!!!!

Can you post a picture? It's been said a million times - Cracks happen. I know of one oven that had at least a 1/2 inch crack and he was able to use it.

[chrispanzer]

Re: help cracks!!!!!!

HOLLY COW!!!!!!!! Man that is some amazing mason work. Your oven is awsome. I am almost embarrased to show you my oven. I saw the picture of your cracks and they look simular to the ones I have. I guess that isn't to bad then. I have posted three pictures of my oven. It is 7:30 pm here so it is dark out. Tomorrow I will post some more. I have all the material to put another thick layer of perlite and portland on the outside and then finish with a coat of stucco around the hole dome. The perlite is to be 3"-4" thick around the entire dome. Do you believe this is a good way to insulate the dome and if so do i need to use a wire mesh to prevent cracking? I am only sugesting this becouse for one I have the material and two it would be the easiest for me to complete.

Thank You For Any Help
Chris

[Les]

Re: help cracks!!!!!!

Chris,

You should be fine w/3-4 inches. I used the blanket for simplicity. The 1/2 inch crack I referred to, he used a blanket as well. When it was lifted for inspection, there was a lot of soot on it but the oven performed well.

Oh yea, the cracks you see are pretty much the norm, and thanks for the kind words.

Les...

[david s]

Re: help cracks!!!!!!

Chris,
It is probable that your bonding agent has prevented moisture in the dome from escaping to the outside hence creating the cracks. I would try slapping some more heatstop over the cracks, leave the whole thing alone for a week to dry, then insulate, more fires, then stucco.
Dave

[chrispanzer]

Re: help cracks!!!!!!

Great thanks. Ive been worried about the cracks alot. Do you think another layer of heat stop over the cracks and a 3-4" layer of perlite and portlan concrete and then a finished layer of stucco will be good. At this time the oven works great ive cooked pizza and bread a few times. I want to finish it and paint the whole thing and to be abe to do that i need to make sure the heat dose not penitrate through and mess up the paint.

[david s]

Re: help cracks!!!!!!

You will be adding tons of water with a vermicrete insulation, so make sure that it is perfectly dry before doing the stucco. Once the vermicrete has set you can start using the oven again. Do 10 firings, then the stucco.Keep the stucco moist for one week, for strength.

[chrispanzer]

Re: help cracks!!!!!!

Awesome I will do that. That is perfect.

[chrispanzer]

Re: help cracks!!!!!!

Perfect, I will do add insulation this weekend and keep you posted.

Thank you all for you help.

chris

[Neil2]

Re: help cracks!!!!!!

"Do 10 firings, then the stucco.Keep the stucco moist for one week, for strength."

This is the way to go. I suggest using an acrylic stucco. Not only is it more 'water resistant" but also has some elasticity to resist cracking. But don't worry about the cracks - as long as chunks of brick are not falling onto your pizza you are OK.

[Eric Pfeifer]

Re: help cracks!!!!!!

During my third curing fire, my dome developed a long, full-thickness crack which extended from the soldiers to near to the top. Smoke was escaping through the crack and so I elected to repair it before the next burn. I used a 2000 degree commercial fireplace mortar in a "caulk" tube, cut the tip to 1/8 inch, and squirted it in the crack and point tucked it it. I let it dry for a day, then fired up to 500 degrees. The joint is solid and no new cracks have developed in the dome.

[mikesuttie]

Re: help cracks!!!!!!

[QUOTE=chrispanzer;78738]HOLLY COW!!!!!!!! Man that is some amazing mason work. Your oven is awsome. I am almost embarrased to show you my oven.

Mate I know how you feel, I am actually embarrassed to show my progress on this site everyone's builds are amazing and neat and mine just looks sloppy! Lol glad you sorted your problem, I'm at the stage of curing now before I insulate and render (or stucco as you guys call it!)