Powder Oven build

SONICJK

Reminds me of...me No, I'm sure of it. I hate him
Finally got tired of messing with my household oven and decided to build a real one.

Basically building this:
https://www.powdercoatingforum.net/forum/ovens-and-booths/2877-my-propane-fired-oven-build

We decided for ease of the build to just build it 4x4x8 as that's the sheet size.
It turned out much bigger than anticipated haha but it should hold a frame. (or 10 lol)

Basically you just build walls with steel studs, face them with 26 ga galvanized (from a HVAC Supply store, 30 bucks a sheet) and put it all together with some Rockwool insulation.

This is where we sit at the moment. Need to build an angle iron frame for the door today and mount the door, cut the hole for the propane heater and wire it up. Hoping to finish it up today.
 

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That's the plan!

Walked out this morning and realized that it was too tall to build a door with the steel studs I've got so I had to spend a damn hour with an angle grinder cutting a foot off the height.
I think it's much more reasonably sized now anyway but annoying nonetheless.
 

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Maritime said:
hind sight and all.

Yep,
Always draw a plan and think it through before you start building!

unfortunately I rarely listen to my own advice ::)
 
advCo said:
Oh yeah, I've been wanting to do this for a while. Want to powder some VW wheels? ;)

If you wanna blast them and send them sure :D
 
55,000 btu is crazy for something only going to 200°. You're also setting yourself up with hot spots and cold spots by running propane in a box. I know that guy's thread says he wants propane to save cost over electric, but you're going to have to vent off 80% of the energy. With ceramic fiber insulation, like a decent oven has, you shouldn't need over a 1000 btu per cubic foot and honestly far less than that. I can get a 10 cubic foot kiln to 2300° with 25,000 btu.

Also: You'll have to be careful to avoid a reduction environment, which will effect color and cure.
 
I was wondering why propane, I didn't read the article. Take you guts out of the home oven and re-use those. It will heat up that larger box fine to 200 and it has the temp sensor and vent controls etc all in it.
 
irk miller said:
55,000 btu is crazy for something only going to 200°. You're also setting yourself up with hot spots and cold spots by running propane in a box. I know that guy's thread says he wants propane to save cost over electric, but you're going to have to vent off 80% of the energy. With ceramic fiber insulation, like a decent oven has, you shouldn't need over a 1000 btu per cubic foot and honestly far less than that. I can get a 10 cubic foot kiln to 2300° with 25,000 btu.

Also: You'll have to be careful to avoid a reduction environment, which will effect color and cure.

it needs to go to ~700 to cure ceramic coating for turbos heads and downpipes etc. 350-450 for powder.
Still overkill, but it will get to temp quickly and propane is cheap. Under a buck an hour to run. It's on a PID so it only runs when it needs to so no real waste other than venting which I believe will be minimal, we shall see.

My shop is maxed out on electricity, we run a robotic welder, a cnc plasma, a cnc mill, a manual mill, a press brake, a brush sander and three manual welders already (on residential power, don't tell my electric company! And that doesn't include the 150+HP running in the wood shop lol) and there's no more overhead for electricity unfortunately.

Insulation is rockwool (mineral wool) good to 2500 or so.
As for hot and cold spots, the heater used has a fan, so there is circulation whenever it is running which *should* help with that.

It's a bit bigger than a 10cuft kiln, it's 128cuft lol. So at 1000/cuft I'd need 128K BTU....

I'm certain lower btu would do the job, but I'd rather overdo it and have it run less often than have to wait 45 minutes for it to get to temp.
There are a lot of more commercial builds of similar ovens running 125K + btu.


I know you know your shit and would probably build a much better one than I am, but this oven is tried and true and a bunch of people use them without issue even in production shops.


The guy who coats our stuff now has a gas oven with more BTU than I can fathom. It looks like a jet engine with the afterburner going. His oven is about 12x12x24'

As for reducing environment, you're probably right but I've been coating in a propane oven for years without a problem, and that's without any circulation just straight burner.
I'd prefer electric, but just no more power to run it.
 
When learning to become a master kiln builder, I was taught a basic lesson= You can fly a brick to California if you have enough fuel.

Mineral wool is good to 1200° and melts at 2000°. "Practical use" is 1100°. You have to get into ceramic fiber to get over 2000° and high alumina polycrystaline fiber to get anywhere near 2500°.
 
irk miller said:
When learning to become a master kiln builder, I was taught a basic lesson= You can fly a brick to California if you have enough fuel.

Mineral wool is good to 1200° and melts at 2000°. "Practical use" is 1100°. You have to get into ceramic fiber to get over 2000° and high alumina polycrystaline fiber to get anywhere near 2500°.

Good thing I'm only going to 700 then :)
 
Alright about 90% done.
Still need to add the light inside and put on a larger door gasket, the one I originally bought didn't take into account my shitty workmanship and big gaps haha.

Ran it up to temp a few times today, works great. About 10 minutes to 400.
Losing heat to the leaky gasket and a few weird hot spots where it feels like insulation may have moved but otherwise works like a charm.

Now I have to figure out a rack system for inside.
 

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First batch done.
Going to need to build a roll in cart for sure.
 

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Now that the ovens done I needed a booth. Tired of sweeping up a ton of powder and having to breathe it in!

3 sheets of melamine, 2 box fans, 30 feet of LED strip lights and here we are.
Came out way better than expected honestly.
 

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Badass. I find that using a 5 sided box is kind of a pain because you have to shuffle around the parts halfway through powdering. Which inevitably results in some powder getting brushed off. Need some turntables.
 
My plan is to mount a bar across the top with a swivel to hang stuff from. That way I can hang it and then reach up and turn the part without having to unhook and re-position.
 
Doubles as a photo booth lol
 

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