Powder Coating 101 - Electrostatic Method

[el34]

I got a HP 6gal 1.5hp compressor when I started PC. It does a great job but isn't overkill or large, also just right for tires-

http://www.harborfreight.com/2-horse...sor-67696.html

It comes on when tank pressure falls below 100psi but there's plenty of air in the tank for uninterrupted use.

I put a small regulator right at the air input to the gun to regulate 8-10psi at the point of use, rather than at the supply side of a hose-

http://www.harborfreight.com/14-mini...uge-68226.html

I took off the bracket and used a coupler. It's true the low pressure PC works at is at the bottom of the scale but it still allows good adjustment and the knob locks in position after tweaking. It is visible in these pics-

[Maximumbob54]

Phase one is now complete. The gear has been purchased. Now I need to put everything together and also glue down some hex nuts to a tray.

[el34]

Phase one is now complete. The gear has been purchased. Now I need to put everything together and also glue down some hex nuts to a tray.

Groovy!

[fcvan]

Jim, thanks for the tips and hints. I definitely think having the thinner tubing will make the gun less unwieldy. Personally, I'm not having too much trouble applying the powder. I'm not using a lazy Susan but am using a plastic jar lid so the tray is elevated and I can easily turn to coat from all angles.

Less powder at less pressure is giving me more even coating and way less overspray than my first efforts. That first time I got a glob/clump dump out of my gun I just shook my head. Then I dumped over the boolits, swept up the powder from the bottom of my spray booth, reset the boolits and coated them again.

Fancy cardboard spray booth, fancy $1.49 paintbrush for reclaiming the powder, fancy $20 oven for baking. Gotta love the simplicity of the whole PCd boolits thing.

[Beagle333]

More playing with ESPC. I did a couple/three hundred of these today. They are soft too.... just one COWW ingot (2-3#) in a 20# pot of stick-on WW.
Here's the boolits:


The color varies because I don't dump out the cup when I add a different powder. And I don't shake the cup, so some get lots of the old colors and some get all new color.


A closer look:


It's mostly HF red, but there is still remnants of dark blue, dark green, zombie green and others in there. I kinda like it.

[Oreo]

I like the speckled look. Pretty cool.

[el34]

Beagle, you're a factory.

[Tech2]

Here is my HF list

Definitely skip the 1/4" yellow coiled hose 20' try 4' unless you tie it to a truck.
I splurged for the the upgraded regulator
It takes very little air to run the gun almost anything should keep up.

[grumman581]

So this one should be plenty good for this???

http://www.harborfreight.com/2-horse...sor-68740.html

According to the manual on the Harbor Freight powder coating system, you need 3.5 CFM @ 30 psi. That compressor would be sufficient.

http://manuals.harborfreight.com/man...4999/94244.pdf

Now, from a practical standpoint, the CFM @ psi rating of the compressor is only important if you are going to be continuously operating it. How long does it take to coat a tray of bullets? If not so long that you don't run out of air in the air tank, then while you are curing that tray of bullets, the compressor could be refilling the tank. It might even be possible to coat a tray of bullets with just the air in a portable air tank that you refill from your shop compressor as needed.

[Maximumbob54]

I made a tray with the hex nuts JB welded down and will throw foil over it:



And I have twenty pounds cast up to be martyrs for the cause of learning:



I bought the kit with all the fittings and adapters that came with the coiled yellow hose and I already hate that hose. But the kit was worth it all the same.

[C. Latch]

FWIW I can't find the size rating on my compressor. It's a C-H from walmart.

I want to coat some more bullets but I've already coated everything I had cast. Maybe this afternoon. Gonna run to the hardware store if I get a chance. When I coat with the bases sitting flat on my foil, some of the base-fin breaks off unevenly in my sizer, leaving the very base unevenly coated. It may not hurt anything but can't help.

[C. Latch]

Also, I bought the extra HF regulator but haven't installed it yet, so while it may be nice, it isn't absolutely necessary; I have been able to regulate pressure well enough with the regulator on my tank. YMMV.

[Maximumbob54]

First SNAFU:

It really helps to pay attention to what you are doing. Like dialing down the pressure at the regulator before connecting the gun. I just blew apart the moisture separator. I hope I didn't just ruin the gun. It's my own fault though. Dang it.

[gds]

First SNAFU:

It really helps to pay attention to what you are doing. Like dialing down the pressure at the regulator before connecting the gun. I just blew apart the moisture separator. I hope I didn't just ruin the gun. It's my own fault though. Dang it.

Lol i did the same thing a few weeks ago.

[Beagle333]

I haven't done that, but I did wonder what part would give first.


(It's only a matter of time..... )

[Maximumbob54]

At least the replacement is less than three bucks.

[merlin101]

So this one should be plenty good for this???

http://www.harborfreight.com/2-horse...sor-68740.html

I have the same compressor at my camp, I needed something portable and tried it. I used it to run a a frameing nail gun and then 2 roofing nailers, WORKED GREAT! The 2 guns had it running alot but it held in there and I believe would be just fine for PC. I've had the PC stuff now for years and just never got around to trying it. I do know it uses very little air pressure.

[bangerjim]

I made a tray with the hex nuts JB welded down and will throw foil over it:



And I have twenty pounds cast up to be martyrs for the cause of learning:



I bought the kit with all the fittings and adapters that came with the coiled yellow hose and I already hate that hose. But the kit was worth it all the same.

Use the aquarium airline tubing like I have recommended so many times. Put in in some of that split plastic wire wrap HF sells along with the gun wire. Makes it a whole bunch easier! You only hve one hose to the gun to fight that way!!!!!!

Just increase your reg pressure about 5-7# to compensate for the flow restriction of the small tubing.

banger

[Maximumbob54]

Before I modify anything I'm trying to figure out the adjustments. The gun has the small dial adjust right in the handle and that seems to help. I set the compressor regulator at 25# as it doesn't want to do anything less than that anyways and I don't want to max out the pressure and slip passed 30# and blow up the gun again. The original moisture separator didn't say anything that I could find but the new one says max PSI is 70#.

BUT...

I'm not getting even spray to save my life. It puffs out one second and is hardly there the next. I can ease the pressure up but is that the problem?

[Maximumbob54]

First stumble in the learning process... The sheet metal is plenty strong and hardly bows when picked up with the weight of the bullets on it. But it does slightly bow and bullets balancing on hex nuts glide right across non stick foil. Go figure. I need to do something to brace the sheet metal so it is solid enough to not bend at all. And the rack of freshly sprayed bullets needs to be right next to the oven or as close as possible to not risk bullets falling over or sliding. I need to find a way of mounting small handles on each side to pick it up careful enough to not tilt it at all. And then it needs to be easy enough to slide into the oven. Enough about the stupid rack...

Second stumble in the learning process... The spray gun is rated at 10 - 30 PSI and with the regulator set at 25# I had some intermittent flow issues. One second it was coating too thick and then not at all. This first batch isn't going to be perfect but once again this is the learning phase. It may just be the pressure being lost from the tank to the gun and the gun isn't really getting 25# to work with. I will dial up the pressure to 30# next time. But enough talking, we want pictures of results, right???

This is them freshly sprayed:


I wore a dust mask and that isn't going to cut it. I need to open the garage door and buy a real mask before I do this again. This stuff really hangs in the air. Once I get the powder flow just right there will be less waste but this time there was a red cloud. Yuck.

This is them fresh from the oven:


It's already a night and day difference in the quality of coating. They lose the dull sheen and it's finally a glossy coating. They feel so much more slick to the touch. With this method the bases aren't coated or at least not with this tray but I'm not worried about that. I'm just in this to avoid bullet lube and bullet lube smoke. The cleaner bore is just an added bonus. The low cost of the HF powder is what drew me back to this and the much better results with the ES spray gun is what made me break down and try this method. I know with this first trial run I used way more powder than I should have but I know I will get better at it and use less. That's the only way I will really be able to tell about cost effectiveness of this method for sure. I also need to try this method with rifle bullets since the finish is so much more even than any other method including the epoxy paint tumble. But for this being the very first trial run I still think these look awesome enough that I will continue to work at this.

This would be the reason for the hex nuts. This one fell off the nut and sat on the tray with the excess powder:


This is a dry tumble vs. ES comparison with the ES in front:


I cannot express enough how good these look and feel compared to anything else I've tried so far. The finish comes out so perfect!!!