Texman Build

[deejayoh]

Re: Texman Build

The Material Safety sheet on the Kaowool suggested i wouldn't want my food touching it.

I think you'd want a low conducting metal - that is why I went with a piece of stainless tube. It's not a terribly good heat conductor.

There's good data on heat conductivity here that others pointed me to when I was thinking this through
Thermal Conductivity of some common Materials and Gases

[texman]

Re: Texman Build

thanks, that explains it. But, brick is better than stainless as far as conductivity. Is the stainless more of an appearance decision then?
Tracy

[Laku]

Re: Texman Build

Depends on how thick the steel is. But same thickens (and size) steel bar is a lot better heat conductor than equivalent volume of brick.

[deejayoh]

Re: Texman Build

I put the tube in for a few reasons
1) My entry floor is 1 1/4 inches of soapstone on top of IFB splits - so I wanted something between the materials for appearance sake
2) It's a tougher edge at the front of the oven, protecting the bricks from chipping
3) The air gap that the tube theoretically offers an insulation improvement. The conductivity stats on that link are for solid pieces of metal - but the tube is mostly air with only about a mm of solid material to conduct heat.

[texman]

Re: Texman Build


After getting some really good advice; i think that leaving my arch open at the back will put a lot of stress on the front of the arch. I was thinking i could add a connection at the back and add strength. But, What is the minumum vent size for a 7" flue?

Area of 7" flue = 38.48 sq in. If i take my flue to 14" x 3" ( add a 2" arch at back) is that ok? Is there a definitive answer on the vent size/oven size/flue size? I see flue size of 3-4 times door height in the FB plans.

My oven is 37" with a door height of 11.125" and width of 18" and dome height of 20" So 3 x door height is 33 and 4 is 44, my 7" flue is 38.48 sq in so good to go right?

If i go with a vent opening of 14 x 3 (42 sq in.) 42" is greater that 38 sq in of 7" flue, so good to go right?
My chimney will be 7 -8 feet tall if that helps in this discussion.

[deejayoh]

Re: Texman Build

Seems to me that you're fine. especially with that flue height!

Check page 21 of the instructions for your chimney: http://www.duravent.com/docs/product/L150_May2012_W.pdf

there is a sliding scale between chimney size and height. Taller chimney offsets quite a bit of the need for for a larger flue

[texman]

Re: Texman Build

Here is the plan:
Remove 1.25" from the outer arch vent brick to bring the outer edge to 2.75" thickness. Add 2.75" arch to rear of outer arch and tie arch together.
This will leave a 3.5" x 14" vent. That is 49 sq inches. my 7" flue is 38.50 sq inches. Transition that 3.5" x 14" to a 7" round flue somehow. Hopefully not break the arch and get to start over on that too. Buy some diamond stocks. I am gonna burn some tonight.
What a trip.
Tracy

Can you get kicked off this forum for making too many mistakes?

[deejayoh]

Re: Texman Build

Just remember....

[texman]

Re: Texman Build

Just remember....
[ATTACH]30439[/ATTACH]

diamond blades are an oven builders best friend.
i am going to take all my hammers and put them away so i dont have any temptation.

[Les]

Re: Texman Build

Can you get kicked off this forum for making too many mistakes?

If that were the case, no one would be on this forum

[Laku]

Re: Texman Build

Thermal conductivity for common materials

[texman]

Re: Texman Build

Thanks Laku, Deejay and Les for the encouragement.
Tracy

[texman]

Re: Texman Build

Here is what happens when you don't pay attention in class and even sometimes when you do.
Removed 1.25" of my outer arch to leave a thickness of 2.75" Took about two hours and some non-OSHA approved methods. But not that bad, just a big mess. I think it needs a little more smoothing later. Advice: Keep cutting until they fall out or you can break loose with your hands. I didn't crack the arch.

Please give me advice on pic C. Any problems with using the brick with the red pointer? That will be easier than cutting out more brick to get back to the actual arch brick behind the piece i added. I think it is fine, but let me know. I get in trouble when i think. The bricks in the pic are just test pieces.

The arch is now 15" wide and will be about 4" - 3.75" deep after i complete the rear of the outer arch. If you like rounded corners in your vent, i can tell you how to do it, but wouldn't recommend it. So my area of the vent will be around 56" going to a 7" flue (area of 38.5") with a 96" chimney. She should suck the smoke out well, i hope.
Tracy
Thanks for your help Gulf!!!

[deejayoh]

Re: Texman Build

Tracy -
Looks good. Nice neat work. On the brick in pic C - it seems like it should work. I'd have some concerns with using a small brick piece like that in what is a super hot spot in the oven (with all the gasses coming out). If the mortar on the outside bond fails, the whole arch drops straight onto your vent floor.
But seems like the only other alternative would be to try to remove the two vertical bricks in picture D in order to get a bigger brick in there. That sounds like it has the potential for disaster.

Trying to think if there is some way to use a full length brick in there that would have the angle toward the arch, and maybe hook over the top of the vertical pieces on the outside? Not sure what the dimensions are

[Gulf]

Re: Texman Build

Wow! Tracy,
What I see reminds me of something.
Years ago, I saw an old man who had taken a pocket knife and whittled out a beautiful aligator from a piece of cedar. One of the kids in my group asked him "how" did he do it. He said that it was "easy". "Just whittle everything away that don't look like no gator" . One of these days someone is going to mortar up a mountain of brick and take a sidegrinder and remove everthing that don't look like no oven .

Great job on the "whittling" of the outside arch.

If anyone asks you what your first meal was from your WFO, you might better answer truthfully and tell them it was "brick dust" .
I don't think that you need to remove the brick behind the brick with the red arrow. You might want to cut and replace the marked brick with one that is a little more square, though and over the next couple of brick get back to your standard arch cut. Just thinking that it would have less chance of popping out years from now, should the mortar degrade. Just invision how brick that are dry stacked together, would stay in place without mortar.