Oven using metal studs and aluminum

[sdold]

I thought I'd post a couple of pics of the oven I'm building, loosely based on the one Jim (Viper56) built. This one's going to be covered in aluminum sheet, and the interior panels are insulated from the rest of the oven with fiberglass tape to allow for expansion and hopefully increase efficiency. Whether it works or not remains to be seen, but here are the pics!

By the way thanks to the guys who answered my questions about the ramp-up time. I was going to post these in that thread, but figured this one was more appropriate.

[pickleboy]

Re: Oven using metal studs and aluminum

just something to keep in mind bro.my big oven is skinned inside with thin alum. panels and over the time that the las owner and myself have used it the alum panels will tend to gro and warp i will try to shoot pics this afternoon for you. not that it it a bad idea, just that you may need more studs to anchor to to keep the inner wals flat. by the way it looks great so far.

[sdold]

Re: Oven using metal studs and aluminum

Thanks for the heads up, I hope that doesn't happen. If it does, it will be pretty easy to drill the rivets out and put in something else, since nothing overlaps the interior panels. Yeah, I'd like to see a pic or two if you get a chance.

Maybe I'd better add a couple of studs as stiffeners.

[Popeye]

Re: Oven using metal studs and aluminum

Looks good!
Not sure about the aluminum on the inside though...

[sdold]

Re: Oven using metal studs and aluminum

It's an advanced, cutting-edge design. At least I'm not building it out of wood or heating it with a propane heater

[Popeye]

Re: Oven using metal studs and aluminum

I hear that!

[Popeye]

Re: Oven using metal studs and aluminum

You might want to consider using button head rivets to attach the liner panels. You could drill .25" holes in the liner and .125" in the studs, that would give it some breathing room to expand and contract without warping as much...
AND, if you ceramic coated the liner panels it would reflect the heat instead of sucking it up....
Just a couple suggestions, so don't take it personal

[sdold]

Re: Oven using metal studs and aluminum

How do you drive Button Head rivets? Interesting idea about the Ceramic coating.

The heating elements arrived today. I think I'll mount them to the bottom before the side sheets are put on. Pics to follow. McMaster Carr has a great selection of elements. I'm starting with two 1500 watt bendable elements.

[sswee]

Re: Oven using metal studs and aluminum

Button head rivets are installed with a standard rivet gun. They just have a button head as opposed to a countersunk rivet. Most speed shops carry the large button heads for panel replacement on race cars. SS

[sdold]

Re: Oven using metal studs and aluminum

I heated up a side panel today with the kerosene heater. First, I had no idea that these things put out so much water vapor. It was impressive to see it condense on the aluminum panels.

After I heated the panel quite a bit, it bowed in the center due to expansion. I think some of you predicted that.

Popeye: I took your advice and drilled out the side and bottom panels, drilled oversized holes in the panels and used steel pulled-rivets with big heads (about 1/2 inch diameter). Luckily I have a pneumatic gun for Cherry rivets, these things were hard to pull with the hand tool but the Cherry gun works great.

Bottom line: The combination of large hole, large rivet head area and the fiberglass tape underneath made a perfect seal, but still allow movement to take up the expansion.

Thanks for the help, guys. Tomorrow I install the heating elements.

Steve

[Popeye]

Re: Oven using metal studs and aluminum

That's great, I'm glad it worked out for you!
LOTS of water in LP, Natural and kerosene... I used to know the gallon to btuh formula, I'll see if I can find it, but it's ALOT

[jrow]

Re: Oven using metal studs and aluminum

Just a question from a non-powder coater, soon to be a powder coater!

If you are building a big oven, with dual elements, to cure bigger parts would it not be advantageous to put a removable baffle/wall in the middle so you could use half the oven for smaller jobs?

John

[sdold]

Re: Oven using metal studs and aluminum

It would. Actually that's a pretty good idea, John. I didn't think of that. I already have a smaller oven, so I might not do it to this oven, but I might change my mind or add it later.

I'm glad you brought this up because it'll change the way I was planning to orient the elements.

It would be pretty easy to make a slide-in wall down the center.

I think I'll do it! Thanks John.

Steve

[jrow]

Re: Oven using metal studs and aluminum

Steve, ETAL,

I guess I'll be one of the fortunate ones. I have a stove that has an upper and a lower oven. The upper oven sits above the burners. Now I didn't say this oven is old but it is!

John

[sdold]

Re: Oven using metal studs and aluminum

Hey guys: here's a progress report on the aluminum oven.

Even though I have not built the top lid yet, and one wall is not insulated pending installation of the electrical stuff, I decided to fire it up tonight. It took about 30 minutes to get to 380 degrees. I am pretty optimistic that it will work OK though, because I was operating with the following deficiencies:

1. Where I'm building this thing, I only have one 15A circuit, and I'm 500 feet from the breaker panel. For the test, I wired both 1500 watt elements to this one circuit (I plan to use two circuits later, much closer to the panel). It's funny, it didn't trip the breaker until the instant I pulled the plug after the test This load brought the voltage down to only 100V.

2. Since I don't have the top lid ready, I just layed a sheet of aluminum over the top. I think a lot of heat was lost in the uninsulated side and top.

I am happy to report that the aluminum expansion did not cause problems, the "floating" inner panels seem to be working. The outside remained cold, so the insulating action seems good too. I'm using plain fiberglass insulation with the paper backing removed. I think using the 1/8" fiberglass tape between the inner panels and the frame studs is doing a lot of good too, because when I felt the inner skin on the uninsulated side, it was way too hot to touch (obviously!) but the stud surface next to the inner panel was only warm, not hot.

With a step drill, it's EXTREMELY fast and easy to install these inner panels with a larger hole in the panel than the stud underneath (for expansion). Having the 1/8" thick fiberglass tape between them makes it easier to tell when you have drilled the larger hole in the top skin, so you don't go too far.

Stay tuned...