Building my first oven!! Help me out.

[JTW37]

Let me add to what CarWiz is saying. I built my oven like you are stating, with 2x2 steel tubing. Had I not had these laying around, I would probably have used the 2x4 metal studs. That said, they weren't using those when I was building mine and I had these (2x2's) laying around which = priceless. . But I have what I have and it works. I do have some heating at the corners because of the lack of insulation. But you just don't lay your hands on that part, at least not very long.

On the other hand, it don't seem to hurt my heating capabilities. But had I to do again (and I may) I will get the 2x4 studs to build with, because of the thickness that I can build into the insulating factor. Course I will also use heavier gage steel for the walls then I did as well. Plus it is going to be bigger. Mine now is a 3x3x6 and I have a 3x3x3 going at this time so, there's my input, for whatever it's worth.

[kg4mon]

I'm building a 4x4x6 and I have around $1800.00 in mine so far but that's everything. I used metal studs, 20 guage for everything except the top and bottom inside, mineral wool insulation, controller from ken. I don't think you can build it under $1000, UNLESS you have some metal lying around or some donated to you. Just the 20 ga sheet metal was $700.00 at $45.00 for 4x10 sheets. I had the metal retailer shear it to size.

[CarWiz]

Originally Posted by wetdream

I kinda understand what you are saying but cant picture how to do it?? Your saying if i make just a 2" wall that where there is no insulation and just sheet metal/stud/sheet metal the heat will get to the outside, right??

Not really, the wall would be 4" thick and have insulation. I'm saying to build the frame so that the inner wall studs have no contact with the outer wall except at the top and bottom plates. Looking down from the top, it looks like this:

1x1 or 2x2 Studs: 0..........0..........0..........0..........0..... .....0
Insulation, 4": ====================================
1x1 or 2x2 Studs" 0.....0..........0..........0..........0.......... 0....0

Your actual configuration or spacing might differ but the point is, other than the top and bottom plates, there's no contact between the inner and outer walls. Even the corners could made to eliminate contact. This type of wall is often used to sound deaden a room in a house/building. The same design can help with hot spots on the outer walls.

[PhredAre]

I built my Oven out of 3/4" tubing, very similar to the drawing presented by CarWiz. Its amounts to a box within a box with contact at the door jam and at the back corners where the inner box is supported to the rollers. There is very little heat loss except at the door jam and the window frame. I have a full 4" of mineral wool insulation between the two boxes. The only thing about doing it this way that it requires a lot more labor. One other comment, placement of the light(s) inside of the oven is important, my thought is to put them in the front, one mounted high and one mounted low so the light is cast upon the objects in the oven and not from behind. Fred

[wetdream]

Why is the top and bottom made of heavier sheet metal?? What is used for this??