ChristopherBlair's 36" Oven

[ChristopherBlair]

Re: ChristopherBlair's 36" Oven

Thanks!
I am letting it air dry now since it has been a week. i checked this morning and it seems to be drying out and less is scraping off the surface.
thanks for the info on the clay flue liner. i was hoping it would'nt cost me a fortune if i go that way.
i appreciate the time you guys give to rookies like me answering our questions.
thanks,
Christopher

[ChristopherBlair]

Re: ChristopherBlair's 36" Oven

Hi, Guys,
I just realized as i was looking at my almost finished dome with joy that i made a boo-boo on the oven opening. it was supposed to be only 12 inches high, but i cut the brick wrong and it is about 13.5 inches tall!
the opening is 19 inches wide, but i am afraid this might let too much heat out. would this be the case in your opinion?
I will looking at it tomorrow to think of some ideas. the opening is fully created and i have maybe four more courses to go before it is closed in.
i can probably make some adjustments to it if it will hinder the ovens performance.
thanks,
Christopher

[JoeT62]

Re: ChristopherBlair's 36" Oven

You could always "dry lay" two firebricks on their tall side on each end of the opening to see if it makes a difference....if it does, mortar them in later.

[DrakeRemoray]

Re: ChristopherBlair's 36" Oven

How high is your dome?

[ChristopherBlair]

Re: ChristopherBlair's 36" Oven

Hi guys,
the dome is 18" high. i could grind the amount away from the opening bricks and lay a piece of angle iron across for the top of my doorway, but i am worried this will cause problems with draw because the smoke will travel up then hit the angle iron then have to go under that then to the vent.
just for perspective, i laid a piece of angle iron on its points on the 13.5" tall door opening bricks and laid my dome bricks on that resting the inside edges on flat iron.
i can provide a drawing tomorrow if needed for visual.
thanks,
Christopher

[ChristopherBlair]

Re: ChristopherBlair's 36" Oven

Hi guys,

I am bumping this post up because i am still thinking about what to do with my doorway issue. i will starting back to work on it sunday, but any info or thoughts would be appreciated.

Thanks,
Christopher

[maver]

Re: ChristopherBlair's 36" Oven

maybe provide a sketch or picture of the issue? If it's a dome it will be tough to lower the opening height. Are you at a point where it will be easier now then later (after you test how the oven works?) Have you assembled the vent?

[ChristopherBlair]

Re: ChristopherBlair's 36" Oven

Hi, Guys,
I did a rough drawing that i hope illustrates my situation. i hope the copy is legible, but if not here it is.

yellow is firebricks.

red is angle and flat iron supporting dome bricks.

grey is chimney (not put up yet).

blue dashed line is where i thought of cutting away and placing angle iron to
create top of doorway.

i could lay angle iron on 13.5" height of brick if the general consensus is "do it".

hope this attatchment works.

Christopher

[maver]

Re: ChristopherBlair's 36" Oven

For some reason I cannot view the attachment in a new window at full size but can view the thumbnail. Am I correct in reading that the inside of the dome opening has a height of 12 inches and you are concerned that the vent is at 13.5 inches? If the dome opening height is 12" at any point then that is your effective height as far as heat retention (the reason to limit the height). Making the vent height (outside the dome) lower may actually impair draw. If the lip of those bricks inside the opening are 12" as I think I'm seeing (trying to read tiny type in the thumbnail) then you should be good.

Marc

[oventhusiast]

Re: ChristopherBlair's 36" Oven

I can't open the picture either. I was wondering if you could cut up some firebrick 'splits' to fit and mortar them up at the top of the opening to bring the height down. I think the Heat Stop would hold them just fine. You would however support them with a form until they dry (cure) a little bit.
Rick

[thebadger]

Re: ChristopherBlair's 36" Oven

Chris,

This might be too late. There's a place in Milford (Brick Tek) that carries the pre mixed Heat Stop. They've told me they are getting the Heat Stop II (mix) once they sell out of their current stock of pre mixed. I'm thinking about getting my fire bricks from there.

Thanks
Dick
Fellow Cincinnati Pizza Oven builder.
Not yet but the boss has given approval.

[ChristopherBlair]

Re: ChristopherBlair's 36" Oven

Hi, guys,
Thanks for all the suggestions. i am more comfortable with the doorway situation than i was before after hearing your thoughts. The inside dome opening is 12 on the nose. The way it is built right now keeps me from having a nice reveal for a doorjam. i will probably use the brick splits idea of keeping 12"until it reaches the higher 13.5 chimney opening. I will keep you guys posted on my progress.

Dick,
it's nice to know i am not the only one in Cinci building an oven. i have gotten many a strange look from friends and neighbors .
i bought my Heat Stop from Dapper company in Loveland. i will end up using almost 4 bags of the stuff. i under estimated the cost of the project quite a bit. my "boss" has been much nicer about it than expected.
good luck with your oven.

thanks for all the help,
Christopher

[ChristopherBlair]

Re: ChristopherBlair's 36" Oven

Hi, Guys,

Well, I have finished the oven (finally) and used it for the first pizza bake today. A bitter sweet day it was when after cooking and letting the oven cool down I noticed cracks going all the way around the outside finish!

Hopefully if I describe what i did and show some photos, you guys can lend some advice.

We finished the insulation layer (6" perlite/portland) then i cured the dome and did the last curing fire last weekend, no cracks that i could detect.
on this Friday we slathered on a layer of Quikrete Heavy Duty masonry coating instead of going the stucco route. It says it is dry in 12 to 24 hours, so about 18 hours later I put a coat of stucco paint on it and called it a day. everything looked good and I was happy with the look and texture.

Well stupid me now wonders if I did something bad because I saw cracks inside on about the sixth course going around and they looked to be about 1/8" thick when fully fired and I expected to see them eventually, but I am afraid I did not give it enough time to dry out from the coating, but the coating did not seem to have tons of water in it to soak all the way through enough to damage the oven when fired, but maybe it did. The coating did dry with hairlines cracks in many spots, but the temp outside was about 70 when applied and the instructions did not say to keep wet.

I checked the cracks on the surface of the dome and they are pretty hot within a couple of inches around the crack. if you put your hand on it feels like a hot cup of coffee. I opened up the cracks by pushing the paint away and filled the big cracks with Heat Stop but am wondering if I should fire it, chisel a way a bit of the coating and fill in with furnace cement or Heat Stop then come back in the spring to re-coat with another inch or two of perlite/portland?

I saw small wisps of smoke coming from one crack too. i am really upset about this with all the time and resources going into it.

I have attached some photos of the cracks. on the outside the biggest is about a 1/4" wide and they go all around near the sixth course of the dome, while some small ones go downwards. I think these cracks go all the way from the inside out.

The outside was totally cold to the touch while cooking, but now after the cracks showed up it is hot around the cracks and has warm and cool spots allover the dome. I think I screwed my oven up is it normal to feel warm and cold spots on the outer dome surface?

I hope I can fix this and not have to tear anything down. Can I still use the oven or shut it down for the winter?

Thanks,
Christopher

[maver]

Re: ChristopherBlair's 36" Oven

Christopher, it sounds like you at least have some moisture in your insulating layer that is being driven out. As you use your oven the heat will eliminate this moisture. I think you might have covered the insulating layer a little soon, but I think you can correct this. Now that you have these cracks I would continue to use your oven and leave the cracks alone for a while (maybe until the spring). You could patch the inside dome cracks anytime but you should repeat curing fires when you do this. Cover the oven if there is any chance of precipitation when not in use to avoid further moisture accumulation in the oven. Then in the spring, chisel out the cover layer on either side of the cracks (an inch or so) and inspect the insulation. If there are large defects in insulation, loose fill those with perlite. Then reapply masonry coating.

Marc

[ChristopherBlair]

Re: ChristopherBlair's 36" Oven

Hi, Maver,

Thanks for responding. I was afraid to use the oven soon after with all the cracking. I did the final coats because the fall is setting in quickly here in Ohio and the rains are falling as we speak.

I had filled in the surface of the cracks with Heat Stop for now until i could find a more permanent solution then covered it with tarp after it cooled down.

Your solution sounds like a good one and i will go with it. I was afraid to use the oven in case it would collapse, but feel more confident now.

I was under the impression you could stucco the dome after curing? i do believe I went too soon then. The masonry coating is for weatherproofing too, would that have been the main culprit since the oven might not be able to breath properly?

Thanks,
Christopher