Need some ideas... Building a small 110v project oven (225* fahrenheit)

[Taiden]

Hey all,

I need to build a 2' x 1.5' x 1.5' project oven that holds a 225* temp and plugs into a 110v socket.

I'm in the planning stages so I need some ideas on:

1) heating element
2) temperature control
3) insulation material?
4) outer structural material



The ideas I had were:

1) 110v adjustable hot plate (for boiling water etc)
2) the adjustability might take care of this, but not sure what to do if it doesn't. thermostatic 110v switch?
3) I have no idea...
4) naturally I want to weld something up, so maybe 14 gauge mild steel sheet?

[welderShane]

Whats its for, powder coating?

[digitalman2112]

Sounds like a powdercoating oven - there are lots of plans online. Most that I've seen at that size use the heating element, and controls from a scrap kitchen range / oven. Given the low temperature you need and the small size, I'm thinking you might also be able to get away with a toaster oven element / control provided it was well insulated.

This build has excellent detail on design considerations and construction methods.He spent $300, but yours is much smaller, so you should be able to cut the cost...

[wskynajar]

Taiden....You could go to wal-mart an pick up one of those toaster-ovens, for like $25 or$30 bucks an redo as you needed.You would have a heating element, thermostat, an even a timer. Thats just one idea.

[wskynajar]

lol....i was a little late on the typeing.

[Taiden]

actually it's for heating up headlights, I do HID retrofits and I heat them up to soften the OEM sealant so I dont crack the lenses trying to open them.

That's why no hot spots are important, I can't afford to melt any plastic.

Can you powdercoat at 225 fahrenheit? If so, it looks like I might have a multipurpose machine

[Taiden]

Oh, I'm a big fan of the toaster oven idea... I bet I could find a used one kicking around in a good will or something.

[jpump5]

Toaster oven.You probably won't even have to buy one.People throw them out all the time because they
are dirty.I built an electric smoker out of one.
Is this project temperature critical?
You may want to monitor the temp. with something else(multimeter w/thermocouple probe,etc.)
at least until you can verify temp. settings.

[towel]

Throw some wood chips and meat in it and you have yourself a smoker.

[jpump5]

Oops- more slow typing

[Taiden]

temp should be between 200* - 225*, never exceeding 250*

[HundredaireSocialite]

Sounds like a cool project.

For powder coating you need around 350-400. I've got a little toaster oven (out of the trash, of course) that does that easily.

I've also got an actual kitchen oven, (also out of the trash) that works fairly well for powder coating. It's a little small for the things I want to start powder coating, but at least it's bigger than my toaster oven. It would work pretty well for a couple of headlights.

I'm going to be building my own oven for powder coating as soon as time/space/money/necessity/planetary alignment allows.

Some of the ideas I've come across online consist of using concrete backer board for the walls, metal studs for the frame, and either fiberglass insulation and or that blue insulation foam that's sold in sheets.

Anyway, a little toaster oven will do about 500*. If you take the heating elements and controls and put them in a box that's 2'x1.5'x1.5', I bet you'll get your 200*-225* temp range easily.

Whatever you do, let us know how it turns out.

[turbocad6]

I've done a lot of headlight retrofits & personally am not much of a fan of the oven method... it puts too much heat into the other components & if your not real careful you will wind up with discoloration or even micro crazing of the lenses among other problems like inner fulcrums & pivots becoming brittle, man times the heat damage doesn't even show itself until your done & put the light back into service...

I use a heat gun & pass it over the seem continually, keep it moving & put enough heat into it to heat soak the seam enough to soften the sealer... average headlight takes all of ~4 minutes to open without damaging anything... the amount of effort you'd put into perfecting an oven technique isn't worth it unless your planning on doing huge volumes like cincity or something, I'd suggest trying a good heatgun first...

[Sandy]

Keep in mind that cookin oven and toaster oven temperatures are "average overall'. The heat up pretty high then shut down and let temps drop quite aways before turning back on again, plus the temps at the top can be quite a bit higher than temps at the bottom.

In short I'd question whether their regulation is accurate enough for critical work.

[Taiden]

Originally Posted by turbocad6

I've done a lot of headlight retrofits & personally am not much of a fan of the oven method... it puts too much heat into the other components & if your not real careful you will wind up with discoloration or even micro crazing of the lenses among other problems like inner fulcrums & pivots becoming brittle, man times the heat damage doesn't even show itself until your done & put the light back into service...

I use a heat gun & pass it over the seem continually, keep it moving & put enough heat into it to heat soak the seam enough to soften the sealer... average headlight takes all of ~4 minutes to open without damaging anything... the amount of effort you'd put into perfecting an oven technique isn't worth it unless your planning on doing huge volumes like cincity or something, I'd suggest trying a good heatgun first...

it might just be a preference thing. i'm coming up on my 14th pair of headlights opened, and so far I prefer the oven method. I've done the heat gun method on probably five and while it works, and is more portable, I would find it much easier to use an oven.

[turbocad6]

what headlights do you specialize in? or do you do many different types? personally I do mostly infiniti fx headlights, been doing a dual projector modification on these, I even built a vacuum chamber for mold making & cast my own clear side marker reflectors which turned into a huge pita... I'd like to see some of what your doing in there

[HundredaireSocialite]

Originally Posted by Sandy

Keep in mind that cookin oven and toaster oven temperatures are "average overall'. The heat up pretty high then shut down and let temps drop quite aways before turning back on again, plus the temps at the top can be quite a bit higher than temps at the bottom.

In short I'd question whether their regulation is accurate enough for critical work.

Maybe that's why my powder coating always comes out so bad.

I'll have to look into alternatives.

[weldbead]

i know you wanna weld up a box...and maybe im crazy...but if its only going to 250 degrees make it out of wood, which is an insulator and burns at over 400 deg

[Taiden]

Originally Posted by weldbead

i know you wanna weld up a box...and maybe im crazy...but if its only going to 250 degrees make it out of wood, which is an insulator and burns at over 400 deg

I had this thought too... but I'm thinking that the element will get much hotter than 250 degrees. and I wouldn't want it to burn anything.

[joefitz]

This might be a piss poor idea, but if you need it to be a specific temperature... Say 225F and leave it there and not worry about it fluctuating temperatures too much you should use something that absorbs heat easier than air and will stay where you leave it. Do a couple of experiments with a hot plate and control the hot plate with a thermostat in the water....

Then you'd eliminate the chances of hot spots and be able to clean off the headlight assembly easily.

If this doesnt make sense it's because I'm exhausted

-Joe

[cantthink]

not much useful input on the other stuff, but if you want to avoid / reduce hot spots.....a circulating fan might help distribute the heat by mixing the air in the oven. my toaster oven has this....makes a killer grilled cheese

[jreynoldswelding]

Looks for a used camper oven. Or look for a big toaster oven.

[Knotbored]

Convection ovens use a fan to circulate air in the oven, and those are/were used in more expensive homes that tend to throw out useful apliances before they wear out.
(the only difference between a normal and a convection oven is that fan)

[kb0thn]

Here is an oven I built for potting electronics:
http://www.aprsworld.com/gallery/shop/IMG_7386

$40 Target toaster oven. Stripped out the control electronics and replaced with a PID controller and solid state relay.

[pyroracing85]

If you have it I would go to 220-240 volts save the amps. What wattage element do you plan on using?

Oh wait you need help on that.

Sorry, I dont know any companies that make them.