Another Texas oven

[wlively]

Re: Another Texas oven

You don't need foil. I used it as both an IR reflective and physical barrier. Since I went with a wood deck roof over my enclosure, I wanted an added layer of protection in case I got a crack big enough to let hot gas/flame escape. With a layer of foil, 2 cermaic blankets, and loose vermiculite there is no way flame or hot gas is going to reach my roof.

I tested my IR floor and dome base temps after my Xmas turkey to test the heat retention with the new door on. I get a 100deg drop every 24 hours. I guess I can be happy with that.

Sorry folks I've come in a bit late on this one - what is KS-4? Sounds like something I needed, I have just finished my 42" dome today with a flurry of brick cutting - it looks pretty terrible actually, I used half bricks all the way and sure enough it was ok up to about the 4th course but after that the overlaps and gaps got rather noticeable. However it is all done now, and awaiting an insulation layer of vermiculite/cement. One thing I am not sure about though - do I need aluminium foil or other insulation over the dome before the vermiculite mix is poured on it? If so, why?

[Kemo]

Re: Another Texas oven

I tested my IR floor and dome base temps after my Xmas turkey to test the heat retention with the new door on. I get a 100deg drop every 24 hours. I guess I can be happy with that.

I have GOT TO MAKE A DOOR!!

[crowtrapper]

Re: Another Texas oven

Re doors: Wade I wonder what sort of door you are using that keeps heat retention so good. I am planning on a fireproof (fibre cement) "inner" door between the oven opening and where the flue is. That door will only be closed after the fire has been removed, otherwise it will stay open. Then on the outside of the entrance bricks, I aim to hang a door which will be made of light steel - a draft door with an opening right across the bottom edge, say 1" high, so that air will flow into the oven easily but the door will fit fairly neatly on the sides and top so that smoke will not come out in my face - hope this will improve the draft and get the fire going even faster than it does now with no doors. Does that sound like a plan?

[wlively]

Re: Another Texas oven

Crowtrapper


I think the entire oven insulation is the most important factor in heat retention. The good door is needed but is a small area. If you look above you will see the door I built, on the cheap. It works well though and I have IR'd the wood facia extensively and cannot pick-up any significant heat getting to them. You don't need anything fancy, just a good insulated plug you can install/remove.

I have not built a draft door , so cannot offer any experience on one. I plan to build one, but cannot say when I will get around to it. I would think you want some sort of way to control the opening size to see what amount of incoming air you need to achieve your desired effect.

[crowtrapper]

Re: Another Texas oven

OK, got the draft door made and installed (not that it took very long to do!) - a sheet of 1.6mm (that's a sixteenth of an inch for you North Americans) steel, the width of the opening but not quite as high, it hangs on 2 screws and has a gap to admit fresh air right across the bottom and about an inch high. It works brilliantly - no smoke in my face and the fire draws like crazy right from the first seconds - makes it a little slower to stoke the fire because the door has to be removed from its screws each time, but whereas before about 95% of the smoke went up the chimney that is now 100%. Have had a few smallish fires there now, but have still to apply outer layer of insulation and also need to make an inner door for when the fire is out, to stop it all cooling off. Not long now before those first Pizzas!!!

[Dolf]

Re: Another Texas oven

I like your door, but the vulnerable foil corners/edges will not last in my life. What if I use a 20x20x1.6mm angle iron frame around the foil covered ver/perlcrete "plug" and use that frame and the wooden outside with 4x 6mm bolts right through to make a sandwich of which the angle iron frame and the wood
9handle side) will thus be the contact surfaces on which to lay it down/bump/drop/throw at the baboon protection?

[wlively]

Re: Another Texas oven

I did not think the foil would last long either, so I doubled over the edges and made it easy to replace the outter layer of foil, just have to unscrew the two end wood pieces. But, it has been a year and a half and I haven't replaced it yet. I do have two small tears on both lower corners, but only thru the first layer and not very big or long. It is the very heavy gauge commercial foil, not the thin grocery store kind.

I will be buying some stainless foil for my airplane project and plan to use that when I need to replace the outer layer, it should hold up and wear much better. I wish I would have used it to begin with.

My problem with the angle iron is that it has enough mass to get hot and hold the heat and if I am reading your design right, will transmit that heat to the wood. That is why I used foil, it does not hold heat at all plus it reflects IR reducing the heat that it absorbs.