36" Pompeii in Indiana, US

[Chach]

Don't forget to insulate the dome as it is recommended to insulate before curing begins so thermal shock does not occur and the oven stays warm longer and more even during the cure process.

[GreenViews]

Thanks for the feedback. I'll take it slow. It's been 12 days now since finishing the dome. Yesterday I laid the top floor layer of splits inside my dome with dry sand/clay mix and lit 2 - 6 hour clean burn food heaters. I checked on it after an hour and was getting near 200 inside top of dome, 115 F floor and lower dome. I will finish insulating today and repeat tonight with same low heat source. I am using a temp door of single layer of sheet metal.

[Chach]

Just don't rush your cure fires even if its for a good reason. Insulate and take it slow.

Ricky

[GreenViews]

Pause Button: I'm hitting the pause button on any new cement until my baby girl goes off to college. Reason being my most important goal is to spend time with her playing with the new oven as she likes cooking and her favorite restaurant is a local gourmet high temp pizza place. Most important goal: spend meaningful time with daughter before she goes off to college. I'd like a month of experimenting with her with the new oven. That means start cooking July 11th, next weekend. It has been 7 days now since I placed dome keystone and 3 days since I bricked in my entry area.

To accomplish my goals I'm thinking of the following steps: (feedback welcome)

• finish laying final floor of splits in fishbone pattern, but lay with dry sand/clay mix
• create a temporary metal flue and vent with 6" ducting and sheet metal I have laying around
• insulate my oven with the thermal insulation but no pcrete until after she leaves for college
• finish my roof as much as I am able in the given time
• Begin low temp fire curing process this weekend (11 or 12 days after dome keystone and 7 or 8 days since entrance walls layed) so it is pizza temp ready for the following weekend
• Finish getting firewood ready and into covered storage from the open air stacks (been a dry summer, so I think we good)
• make a temp door
• begin reading up on dough, prep, etc

I think this will give me enough time to
I added stucco to one of my firewood storage areas and will begin moving from piles in the yard into this covered storage area asap.

Any suggested modifications? ... with assumptions that my top priority is having a new activity to do with daughter before she heads off to college and therefore time constraint of beginning cooking in oven July 11th.

[BeanAnimal]

Don't know, I personally never used, but several builders have and not sure how flexible flexible is. The Uni Extreme I used set up hard though so placing on an highly expanding metal angle may or may not be an issue for Greenville.

As far as the door seal, mine is just a dry fit between the ss steel and the fire brick, is it a 100% seal, no but is does what I need it to do. More important is the have an "insulated" door. Carbon steel has a much higher K value than SS and thinner the gauge better.

I would go further and say that you are not sealing a 1200 degree kiln. I would guess that for residual cooking, by the time the fire is out and you seal off you are at 600 or below. If you want a good seal, then maybe a conventional oven door gasket repurposed?

[GreenViews]

I was avoiding cementing in the flue this morning and I now know why. I have new ideas which allow me to use more attractive and unique materials for the front of my oven as well as preserve the rounded shape on the back end of the oven.


shape a mantle: In the front where the angle iron is, make a rounded mantle by notching firebrick to hang over angle iron with front shaped in a semi-circle

Materials: We have lots of the river stone with fossils from back home. It is really unique and awesome. I think I'll cover the front face and just a little ways back on the sides with this. I will frame and put cement board first out from the front edge of the firebrick and then back a bit. I will use the void space to add insulation at the front of the oven, run wiring and maybe add and insulated buttress for my inner arch and front of the base of my wall area.

Then along the front of the curved mantle, I'll cement the small cut stones with copper veins and other unique cut stones. I did a bit of playing and I think it will look really good and unique.

That's my good idea for now, principally the river stone up the front area of the oven and extending up the chimney section to the roof. I have some questions yet to answer like do I need to insulate the clay flue or just surround with other materials? Should I mortar in wire mesh between or from the top of the firebrick forming the curved mantle or will the refractory cement stick to the front face of it without help?

[UtahBeehiver]

Don't know, I personally never used, but several builders have and not sure how flexible flexible is. The Uni Extreme I used set up hard though so placing on an highly expanding metal angle may or may not be an issue for Greenville.

As far as the door seal, mine is just a dry fit between the ss steel and the fire brick, is it a 100% seal, no but is does what I need it to do. More important is the have an "insulated" door. Carbon steel has a much higher K value than SS and thinner the gauge better.

[GreenViews]

Thanks for the info. I looked on ebay and amazon and cannot find the Uni-extreme product. I can locally get a (non-intumescent) fire blocker I have used in construction called White Lightning Flame Buster. Looking on it's MSDS, I'm not sure it would be safer than risk of exposure to the ceramic rope and I'm not sure if it is even flexible enough when cured or heated to be of use. I did find this link discussing the ceramic rope hazards (posted below). It focused more on workplace exposure and suggested a few increased disease risk areas. I'll wear protective equipment when installing! I'll also revisit my use of this product if I notice any rope fraying or disintegration at all. But I'm hoping In will be able to set it (with sodium silicate based cement) and forget it. I'll keep an eye on it now though. Gosh, now I'm wondering what people use for door seal. I was thinking of using some of the same. Thoughts?

[BeanAnimal]

I looked up the kaowool caulk - it appears to have ceramic fiber in it. I did not check the MSDS, but assume it would be at least more encapsulated than the rope. FWIW - one of their caulks is listed as "hard" and the other "flexible". Whatever that means in terms of hardness.

[UtahBeehiver]

The ceramic rope is the same material as the ceramic blanket and PPE should be worn when working with these materials but once enclosed it should be good. So up to you on whether you seal the rope or not,, it just near the entry point of where food goes in and out. I used a HT caulk called Uni-Extreme(hard to find) that contained no hazardous materials, there is also Kaowool caulk but I am uncure on the MSDS on this one.

[GreenViews]

• Expansion calculation: found source stating over 1000 F rise in temp steel will expand 9 1/2" per 100 feet. I calculated from this I needed less than 1/8" expansion space vertically and 3/16" space horizontally, so I drilled out holes to bolt my 3 angle irons together that were 1/16" too large for the bolts and cut the uprights a bit too short, then verified I had in reality at least the expansion play needed before I tightened the bolts.
• Loose fitting angle iron around bricks: I cut notches for the bricks so the angle iron doesn't bind in any way.
• Thermal break: I had enough insulating firebrick for directly above each of the angle iron except for the ends of the flue for which I then used regular firebrick, notched for the angle iron.
• transition to 2 of 4" clay flue liners I had available. The transition will be over 2.5" widths of flat firebrick placed across the top of the insulating brick above the angle iron. Marked the top 4" circle, started to cut the taper and ran out of time for the day. My youngest graduated and I finished hooking up garden sprinkler system, so short day. Feeling happy about it.
• Bonus: we ordered take out from an expensive high temp pizza restaurant which is my daughter's fav place. Looking forward to being able to make equivalent (or better) pizza with her at home before she goes off to college in fall... and whenever she comes home.

[GreenViews]

The fiber rope I have has stainless braid around it. I was going to tuck it way back in. Have people had problems with fibers getting into food? I tried looking for high temp flexible sealant other than rope and cannot find any available that takes up to 800 F and is food safe. I can keep an eye on it and leave it as an air gap if it starts fraying???

[BeanAnimal]

My wood burning insert has fiber rope - it is very soft and does not appear to be (at all) friable. I would be afraid that the caulk would prevent the rope from expanding an contracting to keep the gap sealed. Maybe just a thin coating of the super wool flexible caulk rubbed over the exposed leading edge to stay any loose fibers?

[UtahBeehiver]

Suggest you seal off the fiber rope on the inside of the vent chamber with some high temp caulk, ie Kwool caulk, vcrete or equiv so the fiber that come off the rope do not contaminate the food area.

[GreenViews]

Impatient entrance build: need to get the clock ticking on curing of flue area so I placed a couple firebrick on edge under where the walls will be and poured p-crete around these and between these and the dome. Any heat loss through this path will need to travel through 3/4" to 1" of p-crete over a 4 square inch area total and low in the sub-floor, so I think will be quite minimal. So today after setting up overnight I placed the entrance brick, tomorrow I'll prepare and set the angle iron (with room for expansion so doesn't stress the brick) and hopefully build up the flue. Oh I did set the entrance brick on top of sand/clay mix and used that for the small area where the insulating firebrick touches the inner arch. Did I do that right?

Thermal breaks: I added 2 which was just my best idea how to get the angle iron into the entrance for the door without turning it into a large heat sync. I have thermal rope which I will glue between the angle iron and the inner arch. On the other side of the angle iron, I have insulating fire brick (very light and insulates very well). Tonight I need to look up the thermal expansion properties of the angle iron to see how much slack I need to allow for movement.