Teardrops n Tiny Travel Trailers

by **D. Tillery** » Fri Dec 10, 2004 11:35 am

It seems that every time I think I will have the time to build that teardrop I've been dreaming about something comes up.

I've been outsourcing my powder coating for 10+ years and it is time to start doing my own. I get something powder coated about every two weeks so I know alot about it. The only stumbling block for me is that I do not have an oven.

I know I can make the enclosure OK but I am having trouble with the guts. It is basically a 300K-500K BTU 350F - 500F drgrees Convection oven approx 4'x5'x8'.

Anyone out there have any advice on this? Free powder coating to anyone who can help me out.

Thanks, D. Tillery

by **SteveH** » Fri Dec 10, 2004 11:49 am

D.

Hint: Use heat resistant materials!

Sorry, I just couldn't resist.

by **Guest** » Fri Dec 10, 2004 11:59 am

D,
Free powder coating, eh?
Question: Will you need a separate oven, or will the spray booth double as the oven?

by **D. Tillery** » Fri Dec 10, 2004 12:02 pm

Yeah. I have never seen a powdercoating oven made from wood and plastic.

This should not be that hard if I can find info on the guts and controls.

Thanks, D. Tillery

by **SteveH** » Fri Dec 10, 2004 12:15 pm

No joking this time, try talking to some of the folks that do pottery fireing. They use ovens that operate at those temperatures, so the controls might work.

by **Guest** » Fri Dec 10, 2004 12:29 pm

D,
If you need the oven to be separate from the spray booth, just build a rolling cart.
I think your controls will amount to nothing more than a thermostat for the oven temperature, an electrical system to keep the powder statically attached to whatever you are coating, until bonding temperatures are reached, burners, fans and a spay gun of course.
Sounds like a steel or sheet metal box with a tempered glass viewing window would work fine.
The firing temperatures that you are after are low, I doubt that you would even need to insulate the oven, if not just for ease of using it.

Just be sure to have a respirator and don't forget your safety glasses. :SG

My biggest concern would be what to do with the propane burner. I don't know if it is required to keep the flame separate from the oven chamber or not. (Remember, you want to build an oven, not a bomb)

Here's a couple of links that may help:
http://www.powdercoatoven.4t.com/
http://www.powdercoatingonline.com/forum/index.asp

by **Guest** » Fri Dec 10, 2004 2:06 pm

Hey D,
Go to that forum and click on this page:
http://www.powdercoatingonline.com/html/powder_coaters_corner_15.html
This is the best I can come up for you, I think if you follow this as a guidline, you'll do just fine.
(It answered my question about what to do with the burners)

by **Steve Frederick** » Fri Dec 10, 2004 2:16 pm

I would go with a box like shown in Dean's link. Insulate it with rock wool insulation. Using some replacement oven elements, or salvaged one's would be easy to control. If you want to go with something like this, I can make you a parts list and wiring diagram for the temperature control portion of the project. I can get you a list of supply sources too, if you like! May even have some odd parts in the basement!

I work in building automation/temperature control, so, I'm sure that it is a do-able project. The hard part will be the construction of the oven box..do you know anyone who might have one of those small con-ex steel storage containers? Like you see on construction sights. I have rented them for storage on construction sites. They are pretty much ready made for this purpose. If I can help with the controls, let me know!

by **asianflava** » Fri Dec 10, 2004 3:52 pm

I took a pottery class in college I was looking for an easy GPA booster but it ended up being a lot of hard work. You can probably make it like a kiln, out of ceramic firebrick. Then use a gas burner down at the bottom. The trick is to get proper uniformity throughout the oven. A blower may fix that problem though.

by **Steve Frederick** » Fri Dec 10, 2004 4:43 pm

asianflava wrote: A blower may fix that problem though.

Any blower used will have to be able to withstand the 500 degree temps. You should try to get a blower that is designed to handle those temps.(blower in air stream, motor out..) Check out Graingers for a selection. If you found a blower with a long enough shaft, you could put the blower wheel on one side of the wall, the motor on the other. Look around in the local HVAC contractor's dumpster for a blower that could work.

by **Guest** » Fri Dec 10, 2004 4:57 pm

Steve Frederick wrote:I work in building automation/temperature control

Whoa-Hoa Buddy!
You Da Man I Gotta Talk To.
I'm going to be building a bell kiln for kiln casting large thick panels of glass. I've got a 200Amp service to my shop and the folks from Dura-Lite have worked up a quote for me on the elements that will be mounted on quartz tubes. Their engineer figured up the element configuration based on the 200A service, size of the firing chamber and firing temperature.
I'll need a programble set up for firing rates and annealing times. I would also like to tie that into a computer here at the shop.
One feature that I would like to add to the mix, is to have a ducted fan setup to blow cool air through the quartz tubes, to aid in cooling the kiln without having to resort to "crash" cooling.
Some of my annealing set points might end up being a few days long because of the glass thickness. The kiln table or tables (two) will have insulated fire brick with low density fiber board. The bell (4' x 8' x 16") will be insulated with fiber blanket and LD board. The Bell will be on a hoist.

BTW- That blower in your post above... Around here we call those squirrel cages.

by **Steve Frederick** » Fri Dec 10, 2004 5:18 pm

Dean, Did the engineer give you a sequence of operation? If I had an idea of what was expected from the system, I might be able to help out. I deal with systems that control whole buildings and processes from a computer via a DDC system. Almost anything they can dream up, can be done with this technology.

Squirrel Cage..Yup, here too! I wanted to reccomend an axial fan,,,way pricey!! Thinking of stuff that can be scrounged :thumbsup:

by **D. Tillery** » Fri Dec 10, 2004 6:51 pm

Wow guys. Thanks.

Dean, I will definitely use a separate booth for applying powder. That site was a big help. It proves it can be done at home. I need a much larger oven and more BTU's than I can afford to feed electricity. I have access to the application gun and I know the Tiger Drylac rep for powder from years of having stuff coated.

Kilns require around 1500 degrees and suck up tons of electricity. I'm looking for around 500 degrees and propane.

Steve, To me the box is the easy part. I have a metal shop and relatives in refinery insulation. I would really appreciate help with the wiring and temperature controls. Any tips on used thermostats, gas manifolds, propane jets would be great. What specific info do you need from me?

Thanks,
D. Tillery

by **Steve Frederick** » Fri Dec 10, 2004 9:45 pm

A dumb question :oops:

Is powder coating flamable?? I was thinking along the lines of electric heating elements. If flamability is not an issue, how about burners from a propane hot air furnace or gas grill? Gas valves from furnaces could be used to stage the heat input.

by **Guest** » Fri Dec 10, 2004 9:49 pm

Steve,
I think that's the way D is heading, because electricity is too expensive.
The large powder company locally uses either propane or gas.

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Any Tips on Building a Powder Coating Oven?

Any Tips on Building a Powder Coating Oven?

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