First powder coating, results so/so, anybody use the cheapo HF unit ? Options

[jsteele22]

Last night I finally got around to using the "Chicago Electric" powdercoating setup I bought at HF a couple of months ago. It was on sale, like $60, and others have reported satisfactory results with it. I had some problems, though, and wondered if anyone has any ideas to help.

The problem was that the powder delivery was very erratic. Whenever I pulled the trigger or jiggled the gun the tiniest bit, a huge blast of powder would come out. Huge. I'd say, 1/16" or so of powder would splat out onto the work. After the huge splurt, the powder would come out in a reasonable manner, and go right where it was supposed to. Gradually, though, the fog would get thinner and thinner, and I'd have to shake the gun a tiny bit. This produced another huge splurt, then another interval of acceptable flow. To get by, I had a scrap metal shield that I kept in front of the work until the splurt was over, then moved out of the way during the intervals of acceptable operation. It works, but it's tedious and messy.


The instructions say to either use 10-15 psi regulated at the compressor, or to use the regulator screw on the gun itself. I'm using the shop at my work, and the compressor is off in a different room that I don't have a key for. So I bought a cheapo HF regulator that I screwed onto the gun, and before loading it with power, tried to test the operation. With the trigger pulled, I could - barely - regulate the pressure, but as soon as I released the trigger, the pressure would climb to line pressure. The POS Chinese regulator wasn't regulating. Then, based on the instructions, I removed the regulator and tried regulating the air with the screw built into the gun. No way of knowing the pressure, but from the sound I could hear the rate of flow and trim it to something reasonable. In any case, the air flow is smooth and steady.

Any tips or suggestions ? The obvious thing to try is buy a non-crap regualtor. But has anyone had luck using the metering screw in the gun itself ? My hunch right now is that maybe I had the air flow too slow. How rapidly should the powder coat the work ?

TIA, Jeff

p.s. I'm off skiing tomorrow; won't be back until Tues.

[Rusty]

Scott is right about shaking the powder.

The powder should spray out pretty evenly. What you're describing isn't normal. Might be you have a defective gun... after all, it is HF.

Were you spraying powder during high humidity? I've found that can cause problems.

[jsteele22]

Scott is right about shaking the powder.

The powder should spray out pretty evenly. What you're describing isn't normal. Might be you have a defective gun... after all, it is HF.

Were you spraying powder during high humidity? I've found that can cause problems.

My hunch is that humidity wasn't the issue. Once the powder came out, it seemed to have a very "dry" feel/look to it. And during the "good intervals, it did make a nice fine fog. I was working indoors (under a good exhaust hood) in a climate-controlled building.


Right now, I'm thinking the shaking idea will fix it; I'm certain that the powder wasn't shaken or agitated in any way, except for turning the bottle upside down once after it attached to the gun. Also, it could be that b/c the powder was compacted and the very first splurt of powder was such a suprise, that I backed off the air and wasn't really using enough flow. Stay tuned...