help with build needed

[laz]

Hello,
I need help! Im building a oven that will be approx. 27.5 inches in the inside with a dome height of 16". Is a 10 high opening ok? How wide should the opening be and what length is acceptable.? What size chimmney should I make? Any help or advise would be great

[cobblerdave]

Re: help with build needed

G'day Laz
27.5 wide oven should have a dome height of 13.75 inches. 63 per cent of that for your door opening, 8.5 ins. Door width usually should be a bit under half the width, but a 12 in pizza needs a bit of clearance on the sides so I stick to half that's 13.5 inchs. 36 to42 inch ovens need an 8 in chimney, your well under that so a 6 inch will suit and be commonly available
Regards dave

[laz]

Re: help with build needed

Dave,

Thank you for your reply. Do you see any harm making the dome 16" and the entrance 10h x 16 wide? I purchased a dome from Superior Clay and thought I could set it on top of my chain brick to eliminate the closing in of the dome of a 36 inch oven. Well that wont work because the dome is 7" deep and :confused the dome would be very high when the chain would be at a diameter for the dome to fit. I wanted to build a 36 " oven but I'm now down to the 27.5. Also, should I encapsulate thewhole oven in refractive cement then put the blanket on or vise versa.Again thanks to all who reply.

Laz

[cobblerdave]

Re: help with build needed

G'day laz
From what I understand (correct me it I got it wrong)
You have a pre built dome of 27.5 in dia with a door already cut. You are planning to set it on a ring of brick raising you dome height to 16 ins and your door height to 10 ins. That's still around the 63 per cent mark so it should still breath alright. 16 ins isn't that high of the hearth, your cooking surface.
The domes 7 ins thick??? I myself would clad the bottom part of the dome to marry the dome to the brick and except some cracking. I would not add to much mass to that dome as its pretty thick and would slow down your heating times considerably. Add the blanket on that.
Hope I have understood this enough to make my response helpfull
Regards dave

[laz]

Re: help with build needed

Dave,
I purchased a dome that is 27.5" in diameter. I'm planning on laying a soldier row so I have a inside oven size of 27" . The dome is 7" IN HEIGHT FROM RIM TO OUTER EDGE. I was going to use heatstop mortar to mortar soldiers to floor and motar the dome to the top of the soldier. Then I was going to use refractive mortar ( heatstop) to cover the dome and soldiers to marry them into one.then I was going to put a blanket that is used in a high temp furnance. I was not sure if the width of the oven 27 id for mine would be ok w a 16" height from floor to top of the dome. The more I read the more questions I have, that is why it is ampleasure to talk to you. My soldier row would be set so the bigger face would made the inner circle. This should give me about 2.5 " thickness for the brick and the dome. The dome thickness is around 2 2.5 ". What would you recomend for door opening h/w? The place where I bought the dome builds their ovens to 13" I just thought the 16" height would allow a higher door and it just looked a whole lot better on the dry run. Again thank you for your input and time. I look forward to hearing from you. If its easier you can email me at toelasslo@yahoo.com.
Thank you
Laz

[cobblerdave]

Re: help with build needed

G'day Laz
That's a pretty flat roofed dome I can see why you want to raise the roof and door height. As per my previous post 16 in dome with a 10 inch door height is good enough . 63 per cent is perfect but close enough to 2/3 of the height will work.
Your sensible to sparg a layer of refractory on the outer of the solider course to buttress and prevent outward movement
2.25 is a good thickness for the dome and will give you a reasonable heat up times and have enough mass for baking.
You had better send some pics .... The paper lip icon thigh next to the smiley face starts it
Regards dave

[laz]

Re: help with build needed

Dave,
How wide would you make the entrance way. I had mentioned 16" in a previous post, but that may be to wide. Your thoughts.. also how long should the entry way be before entering the oven chamber? 10h x ?w X?l. I will sen d pictures when I figure out how to do that.I have acess to insulating fire brick, would these be a good option for the insulating pad? They have the #23 stamped on the side. They are very light weight and were used in a high heat furnance between the fire brick in the chamber and the outside furnance wall. They are new and free, I was going to lay them in heatstop and cover them with the same. This would make up my insulating pad.My thought process are they should be as good or better than cement & vermiculite. I just need input from someone who is familiar with them. My last question is would you incase the dome also when marrying the soldiers row to floor. Would it not help keeping the expansion contraction work in unison for all the parts. The manufacture states to heat stop all the outer parts. Just wanted another opinion. Again, THANK YOU for your guidance!!!!.

[cobblerdave]

Re: help with build needed

G'day
Actually I said 13.5 ins. Best practice is to have it a tad under 1/2 the width. But there are more practices than that. The practice of making a 12 inch pizza is one. By your oven height you should have a door of 12 ins roughly. No pizza clearance. So I'm saying go 13.5 and give yourself a bit of clearance. 13.5 is half your width not 2/3rd or anything that could lead to heat loss.
Of course your the builder its your call but I'm just saying bend the rules a little not completely break them ....
Regards dave

[cobblerdave]

Re: help with build needed

G'day again Laz
Finally had my evening meal ! So I'm ready to answer as best I can
Insulating firebrick .... What a champion find!!! Definitely a great hearth insulation. Better than pearlite Cement, no buckets of moisture to dry out. Don't you dare mortar them in any way. Contain them on the outside.
Same with the base of that solder course don't mortar it down rather mortar the units together only. The dome has to be free to expand and contract independent of the hearth and insulation.
Entrance depth. Brick and 1/2 deep say 14 ins roughly. Enough to support the chimney and stop the wind from blowing in at the sides, and they are important to maintain your eyebrows and fringe intact Height and width .... Go as big as your able you don't want to find yourself trying to operate your oven through a small tunnel .
In saying that mines 2 and 1/2 bricks deep but because it on the front of a 42 inch oven and 25 in wide and 15 inchs high its big enough.
Encase the dome with a sparging layer particularly with the solder course as it needs to be supported to to stop any tendency to expand out wards.
Regards dave

[laz]

Re: help with build needed

Dave,
Thanks again for the information. Just to make sure I have this right; The insulating fire brick(very light weight) do not get laid in mortar or covered over the top? I was under the impression before our conversation that they would be encased with high heat mortar to make a pad like the ones described in the forum using vermiculite. I then will spread a thin layer of fire clay to set the floor in place, do not mortar soldier row to floor or dome to soldier row, cover the whole outside with heat stop mortar, cover with ceramic blanket. I will take some pictures and find someone to upload them. Thanks again and you input has been a great help.

Laz

[cobblerdave]

Re: help with build needed

G'day
You ruin there insulation value by separating and binding the them with a heat conductive material. The mortar will only form heat conductive pathways.
To upload a pic click on the paper clip icon at the top of the post window near the smiley face. It will open a window that will enable you to upload an existing pic from. Hit the browse button, hunt and select a pic. When it comes back to that window, hit the upload function, and wait to upload. Max of 5 pics for a computer and usually 1 for I- phone. Closing that window and get back into the post window you'll find if you click on the paper lip icon again it will contain your pics. Its just s case of selecting one or the lot to include at the base or in your text. Hope this helps
Regards dave