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View Full Version : Questions abut building powder coating oven at home.



Nottso
12-31-2012, 12:16 PM
I didn't want to high-jack the thread about powder coating guns started by Spm1101, and my questions are about home built ovens, so I thought it might be better to start a new thread. Mods, please let me know if this is proper protocol, or if I should have asked in the other thread instead. Anyways...

I also want to start doing my own powder coating and I plan to build my own oven. I have a heating element, with thermostat, that's 36" x 36" and runs on 240v (which I have). My plan thus far is to frame it out with sheet-metal studs, skin it inside and out with sheet-metal, and use mineral wool insulation in between. The oven will be upright, 4' x 4' at the base and 8' tall.

When I build the oven, where should I put the element? Conventional wisdom would seem to dictate putting it t the bottom, since heat rises, but I was wondering if any of you guys that have previously built your own ovens, or work in powder coating, have any insights. Would it maybe be better with the element at the top, and if so, why?

Also, what gauge sheet-metal have you guys used, and did you end up happy with the choice? I use quite a bit of 11 gauge (1/8" nominal) around here but I would just as soon use 14 gauge, or maybe even 16 gauge, to keep costs down and make it a little easier to move around (it will be on extremely heavy duty casters).

Thanks in advance for your thoughts.

Tito
12-31-2012, 2:04 PM
Most older household ovens use 2 elements top and bottom, each 110. When you preheat or broil, both elements go on to use 220, regular 'bake' is just the bottom element at 110. The bottom element only is good enough for maintaining temps in a preheated oven.

I would just put it on the bottom, and let it warm up a bit. Preheating parts before spraying helps.

As for sheet metal, as long as your framework and insulation are both solid, 16g is enough. Household ovens use thin gauge.

There's a lot of plans on the web for building ovens. Some are fancy, some are not. I got a crappy GE oven free off CL and put it on rollers, wired it for a 220 plug and would just plug it into my dryer outlet in the garage when needed. Good for small stuff, but would not fit a 19" wheel.

I never built a bigger oven, but had plans to tear apart the free CL one and use the elements, similar to the size and method you are doing.

sohcool
12-31-2012, 2:27 PM
18 gauge would be fine. Use rock wool insulation in the panels.

Multiple elements will cause the oven to heat up faster. On a 4x4x8 you could go either way on the number of elements.

A cool idea that I saw once was a guy who built his oven to break apart in panels. They were screwed together when he needed the oven, and when he was done he could dismantle it and store it in the corner. Kinda cool.

Just sheet metal rock wool inside, and they all screwed together with wood screws. I'll see if I can find the site. It was pretty radical. Has a wheelie cart inside and everything.

Reid
12-31-2012, 3:42 PM
I have thought about doing the same my CL double oven but always loose interest when I try to figure out how to seal the door

sohcool
12-31-2012, 4:08 PM
I have thought about doing the same my CL double oven but always loose interest when I try to figure out how to seal the door

Could get real crazy and buy a seal made for that. ;)

Tito
12-31-2012, 5:35 PM
I have thought about doing the same my CL double oven but always loose interest when I try to figure out how to seal the door

Most local DIY appliance parts shop sell that fire rope by the foot. They probably would have some other parts that would come in handy. I've rebuilt old 40's fridges and they have lots of parts that can be used to seal heat or cold.

Reid
12-31-2012, 9:34 PM
I hadnt thought of that but it hasnt really been a priority either. Since the fridge was brought up, wouldnt that make a pretty good oven shell

Tito
12-31-2012, 10:33 PM
Most are plastic inside. The old ones are steel outer and inner with insulation. Some were ceramic coated steel inside. Don't know what kind of insulation though, might not be fire-safe.

Nottso
01-01-2013, 12:54 PM
Thanks guys. I always like to hear from those that have "been there, done that." It seems that I'm on the right track. Now to just find the time....

IIIsticks
01-06-2013, 2:24 PM
I think I might try what this guy did. He made an oven out of a hot plate and some ac duct. http://www.youtube.com/watch?v=Ql-MFcScE3c I have a toaster over for small parts but most are to long and if this works it would be great for forks and longer parts.