Texman Build

[deejayoh]

Re: Texman Build

Couple of thoughts

1) I have seen posts of "concern" regarding caulk separating from the heat break, but no posts where someone using the right material (i.e., a high temp rated caulk, not fireplace caulk) has actually experienced failure. My experience with the high temp caulk so far gives me no pause for concern. It is quite solid.

2) Stainless is a MUCH better heat conductor than firebrick, so my point is you would have been better off w/o a heat break than you will be with stainless

3) To your point, FFX - the purpose of a heat break is not to keep the entry arch cool while firing. I agree with your point about gasses heating the vent flue - it is one I have made too. But I think the purpose of the heat break is really to maximize heat retention in the dome on day 2 or 3. Theory is that after firing, the flue vent is an open, uninsulated structure that when attached to your oven, is basically a giant heat sink pulling heat out of the dome. So the idea is that if you can reduce this heat transfer, the oven will not cool as quickly and you'll have higher cooking temperatures on day two or three. Makes sense to me. Insulation is about heat retention too - not firing temps. So why put on 3 or 4 inches of expensive insulation and leave the front of the oven to leach heat? And since Tracy already has a break, makes sense to me to maximize the benefit.

[flyfisherx]

Re: Texman Build

I really don't see a reason for a break in the first place. I had a fire this weekend that cleared my dome perfectly. No amount of break was going to stop any heat from seeping over to the outer arch. In the initial stages of my fire, I had flame licking the vent. All the vent gasses and heat have to go there anyway to escape up the flue. I put a plywood door in place after I was done Sunday night(real door in the works) and this am I checked and I easily still had 300 degrees or more inside. I could not hold my hand on the inner arch brick.

This is just my 2 cents from my experience. The concept in theory sounds good but I just don't think it would provide any merit.

[texman]

Re: Texman Build

well, i thought that using 3/8" square rod for appearance and using rope/caulk behind the stainless for the rest of the break would be ok. I would lose the benefit of the break for the 3/8" that the stainless occupies somewhat, but would gain a clean food friendly transition. I know stainless is on the better end of the spectrum as far as metal conductors go, but the whole point of a heat break is to break the heat seepage from the dome via the outer arch/vent. i have seen many posts of concern of the caulk and rope being separated from food contact. I just figured a 3/8" uncompressed mortar fill would just crumble. Do you think it would hold on the arch? the bottom floor break could easily be filled with mortar/ash/rope. I guess the others that have used stainless on the floor break have accepted the inherent conductive shortcomings of stainless and used it there. I know you used Kaowool and rope i remember. I just wanted to cover those two up with food friendly material in the arch as well. Are there any other food safe materials to cover the rope/kaowool?
Tracy

[deejayoh]

Re: Texman Build

Whoa there Tracy...
Why do you want to fill the heat break with Stainless rod? It conducts heat about 10x as efficiently as firebrick (a rating of 1.4 vs. 16 according to this link)

You would be better off filling it with mortar. Maybe I've misunderstood your post, but I'd scrap that plan. You want non heat-conductive insulating material. CF rope, caulk.

[texman]

Re: Texman Build

Good idea.

[UtahBeehiver]

Re: Texman Build

Tracy,

If you still have your arch form take it with you if you have them bend the rod then it should match exactly.

[texman]

Re: Texman Build

Tom
The rod is solid stainless. Not sure if this stuff will bend, break or kink. I thought the heat might help.
Tracy

[Tscarborough]

Re: Texman Build

Fill it with damp sand when you bend it to keep it from kinking.

[texman]

Re: Texman Build

Come to think of it, the place i purchased the pencil rebar from does all the custom fabrication of that, so i bet they could do it. i will check them out.

[UtahBeehiver]

Re: Texman Build

I bet a 1/2" conduit bender from a rental store would work. Probably cheaper than a rebar bender.

[texman]

Re: Texman Build

not that i know of. maybe i could rent one from home Depot? never used one or did much bending for that matter.
Tracy

[UtahBeehiver]

Re: Texman Build

Tracy,

Any access to a rebar bender/cutter or even a conduit bender that electricians use?

[texman]

Re: Texman Build

What is the best way to bend/shape 3/8" solid stainless for heat break?
My plan is to fill my heat break with the stainless square rod. The bottom will be a straight piece, but i thought i could bend the rest in the shape of the arch and fill the entire break with stainless. I have square rope gasket and kaowool for behind the stainless. I was thinking that i could cold form the rod in a vise and/or tubing to the arch shape and somehow get that in in one piece. I have a small propane torch for heat that i may need to use. (may have to be a 3 piece overall if i cant get a one piece arch piece in there)

So the plan is this: 1. 3/8" rope gasket in first in multiple passes( i got 20' of the stuff) 2. the stainless rod as the appearance piece from looking inside the arch. 3. the kaowool from the outside to seal it all up. That way the ceramic is encased by stainless on the inside and kaowool on the outside and neither the rope or kaowool is in danger of food contact and i have a 3 piece heatbreak, which should be good.
Tracy

[texman]

Re: Texman Build

Anthony
The 2' above nearest 10' is the general rule for flue draw, i believe. The codes will vary by city/state from that. I am outside the city limits and don't have to have inspections and permits, so not familiar with that. I think code is the minimum and should be the starting point and try to exceed that when possible and meaningful. You might reach out to Planophil. I think he had to deal with the code folks in plano. Sorry i couldn't help more. Good luck on your build and post lots of pics.
tracy

[aiannar974]

Re: Texman Build

Hello Texman - I live in Lucas just a stones throw from Murphy. You mentioned regualtions about chimney height and distance. Where do I find this information? I was planning on buying one of the small prebuilt ovens like the primavera and did not think about this.

Thank you,

Anthony