PowderCoat - curing work light

Started by burningman, June 05, 2010, 02:07:05 PM

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burningman

Just wondering if anyone has used a high powered work light for curing powder coated parts? I'm thinking here of the work lights they sell at Home Depot. Would this work:

http://www.homedepot.com/h_d1/N-5yc1vZ1xr5/R-100664508/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

Also, infrared bulbs seem to be a popular choice for powder coating - is there a reason for this, and can IR bulbs be sourced easily?

PRR

Lamps only heat one side, which may not be what you want.

Two of those super-strong very-cheap lights face-to-face, to cook both sides, may be a bad idea. They are designed to throw most of their heat "out there". Having another lamp throwing its heat IN to a lamp may over-heat, potentially dangerous. Also two 1,000W lamps on one 20A circuit is at the 80% loading the Code limits us to, so technically you can't plug-in the smoke detector you really should have near any heat process.

There's no strong difference between large incandescents and "IR" lamps. The visible inky lamp turns 95% of your electric bill into IR and lasts 1,000 hours. The "IR" lamp makes 97% IR, may have a filter to cut visible light, and because it does not have to run "white-hot" it can run 5,000 hours. If you keep french-fries on the table for hours, "IR" lamps are for sure the way to go. More heat on objects than to the room, less bright glare, and in all-day everyday service the replacement costs are low. But for a few dozen 1-hour bake-offs, the work-lights are expedient because you can use them for other stuff (midnight repairs, photography, etc).
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burningman

Thanks for the response. I'll only be baking uni-directionally, top/sides. I'll give one of these a try.

John Lyons

Powder coating usually take 400 degrees to liquify the powder
and want a very even heat. Work lights will not do either.
A toaster oven for small jobs and a home oven can be had for
almost nothing if not free.
Basic Audio Pedals
www.basicaudio.net/

burningman

I've been using the toaster oven method for smaller things but I'm at a loss when it comes to things like rack face plates. What are the differences between the IR lamps sold by eastwood and a worklight?

http://www.eastwood.com/2-x-3-medium-wave-curing-lamp.html

John Lyons

Are the eastwood lamps for a powder coating application or wet paint?
Typical work light are Halogen, Infrared is a much different light/heat.
Basic Audio Pedals
www.basicaudio.net/

burningman

the IR curing lamps are listed under powder coating. The wattage of these units seems to be a bit more than what is being used in work lights. I wonder what the differences are between IR and standard halogen bulbs?

PRR

The Eastwood thing is a room heater, mounted on a handy stand.

They sell it for curing PAINT, not powder-coat. Car paints are formulated like fiberglass resin or epoxy: you mix two parts and it cures in hours, unless it is cold, then it takes longer. A careful hit of heat makes it harden faster.

Similar techniques were used when car paint was high-solvent lacquer. Car factories simmered the solvents out in long hot tunnels lined with IR heaters. That type of paint is mostly illegal now.

The 500W lamp and the 1,440W quartz heater do similar things. The lamp is smaller which means it can put higher heat in a small area: it can just-barely, maybe, melt powder-coat. (I agree that a toaster-oven is much more sure, and controllable.) At rated 2'x3' coverage the Eastwood heater can maybe hit 200 deg F, though this may require insulating the back of the hood or roof.... I think it is only meant to reach "warm summer day" temps when your paint-job runs into a cool evening. Since it is a good 18 inches long, a 4" box set very-very-close is a waste of 3/4 of that 1,440 Watts.

Eastwood's $430 IR powdercoat curing system approaches 1,800W and will cure 10"x10" at a time. It includes an IR thermometer so you know how hot your part gets.
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burningman

That's got me confused because the lamp is listed under powder coating and the Eastwood Hotcoat book confirms the use of curing lamps for powder coating.

amptramp

A long time ago (in a galaxy far away), I had a summer job at a small rubber company which required me (among other things) to build a 12" x 12" infrared heater from four IR lamps for softening ABS plastic for vacuum forming over wooden molds.  The intent here was that we could build ABS grocery cart wheels with the tires molded on in one step.  When the plastic was hot enough in one area, it would often scorch another, so you have to be aware of the temperature variations.  It would reach 396 degrees F in the hottest area outside in 95F Toronto summer heat and you could form the ABS at the consistency of leather of the same thickness, but usually something looked burnt.

If you go to garage sales, you can get a toaster oven suitable for a 1590BB or larger box for $5 to $10 and it will not have anywhere near the same uniformity issues because convection circulates the air.  Much cheaper and more uniform and you have thermostatic control over the temperature.

If you are going to build pedals for a living, check out industrial auctions.  Enough companies are going under that used processing equipment is available dirt cheap.  Want a thermostatically-controlled oven of the type you can find in the McMaster-Carr catalog?  It's out there.  You can find it online in industrial auctions (and I don't mean evilBay).

robmdall

The IR from Eastwood will be fine for Powder cure. Here is a neat little article about powder and IR cure http://www.pfonline.com/articles/020302.html

dudleydoright

According to the powder coating manual, the process creates some pretty toxic offgas so your foodie kitchen ovens are a no no, as are any with an open flame. Suggest doing it where there is plenty of fresh air flow. Also they specify a gradual cooling, as in leave the cheap goodwill toaster oven closed and let the temp gradually ramp back to room temp for the best results, ie durability and asthetics.

amptramp

I picked up a spare toaster oven at a garage sale for $5.  This means I don't have to contaminate the one I use for food.  It has thermostatic controls and wire shelves and is large enough to take any Hammond enclosure and it will fit most with the lid beside it.  I am not a fan of IR - there is too much temperature variation over the surface for either paint or powder coat.

defaced

#13
QuoteI wonder what the differences are between IR and standard halogen bulbs?

The amount of energy given to the different spectrums of light.  To be efficient, an infrared light is most efficient when it doesn't emit visible light.  So most of the power in is given off as heat.  Conversely, a standard light is most efficient when most of its energy is given off as visible light.  Sure there's a big spread between a perfect heat source and a perfect light source, but if you're trying to get maximum heat out of a device, wasting precious energy on generating visible light is counterproductive.  
-Mike

theundeadelvis

Not sure if you have the space or not, but I would look for a used kitchen oven to dedicate to it. Good chance someone may be getting rid of one cheap. I see them in the paper frequently, when someone bought a new one.
If it ain't broke...   ...it will be soon.