Powder Coating 101 - Electrostatic Method

[MacFan]

Hi Drysound, I'd say 50% have very slight pin holes. At worst case they're small, maybe .015 to .020" in diameter. If my hand is really steady placing them down then there's no pinhole. Even with the imperfection I can't imagine it affecting the coating or balance much at all. My bullets are all tumble lube grooved. I try to pick up at the top groove. I found if I tap them gently when I pick one up it knocks off excess powder but leaves plenty to coat. It sounds tedious but it goes pretty fast. I find myself with nothing to do after the first couple batches while I'm waiting for more to cook. I guess I could clean the garage... naw.

Update: I shot some bullets with a candy blue powder coat yesterday and used the bullet lifter to put them on used but clean foil. Maybe 10% have slight pin holes from the lifter. The ability to flow and fill in minor imperfections may vary with different powders.

[el34]

El34 how about the 6L6? Anyway, the HF is about 12KV DC. You could clip the bottom (neg) portion but get a reduced avg DC. The fancy ($$$) units use a varying (modulated) DC to reduce shadowing. I put 0.023 holes in the nose and no accuracy problems I can see, but no place to shoot > 100 yds yet.

6L6's work. But the Marshall purist would lean towards el34's, I'm in that camp.

A few months ago I tried parchment paper under the boolits to prevent gluing them to what they're sitting on. It worked I think but I was brand new to PC and too stupid to know what a good coating should be. If true continuity is not actually a requirement for a static charge system it would increase fixture design options. All I'm thinking about is a very thin non-conductor, re-inspired by the teflon idea.

Maybe pulse-modulating the high voltage generation wouldn't be too tricky but would require discovering the HF circuit. Don't know if the juice is worth the squeeze though.

[MacFan]

All I'm thinking about is a very thin non-conductor, re-inspired by the teflon idea.

I wouldn't be surprised if it was PTFE or Teflon on the non-stick side of the foil many of us use.

[el34]

I wouldn't be surprised if it was PTFE or Teflon on the non-stick side of the foil many of us use.

I thought the same thing so I checked with a multimeter. It's zero-ohms conductive with feather-light pressure on the meter probes. The no-stick property must be from something else.

[Beagle333]

The HF red came out perfectly on the .357 boolits. I have them sitting on small machine nuts under the foil. I managed to coat a sandwich baggie full of them and only had two fall off the little nuts. It is quite a game of careful balancing though, from the spray table into the toaster.

The nuts are not JB-Welded to the tray, I just placed them in rows, put the foil over them, and pressed it into shape. The foil keeps the nuts from moving until I get the boolits set on em. I didn't know what spacing I was going to need, so I didn't want to permanently fix the nuts to the tray until I had that figured out, but I am now thinking I don't have to glue em down at all.

[bangerjim]

The HF red came out perfectly on the .357 boolits. I have them sitting on small machine nuts under the foil. I managed to coat a sandwich baggie full of them and only had two fall off the little nuts. It is quite a game of careful balancing though, from the spray table into the toaster.

The nuts are not JB-Welded to the tray, I just placed them in rows, put the foil over them, and pressed it into shape. The foil keeps the nuts from moving until I get the boolits set on em. I didn't know what spacing I was going to need, so I didn't want to permanently fix the nuts to the tray until I had that figured out, but I am now thinking I don't have to glue em down at all.

I have found 1" spacing for 45's and 3/4" for 9/30/38/40's do very well. HF red works VERY well, but as I have said earlier, my 45 1 ogives look like lil tubes of lipstick!!!! HA....ha. I do use it for 38's and 40 HP's.

Your slugs look nice!

bangerjim

[el34]

Beagle-
They look great. How difficult was it to pull them off the foil?
And did you get foil or PC flanges on the boolit bases? Maybe a pic?

Tomorrow I'm gonna do a bunch of 357 with gloss black and I want to try the nuts and foil.

[Beagle333]

They pretty much fall over and off the foil when I take em outta the toaster. Here's what it looks like after. Some of the nuts have shifted slightly from their original position while jostling it around (I didn't know I was gonna be taking a pic of the tray), but I think I can load this tray again and test it tomorrow am.



This is what the base looks like. Hardly any flashing.


But it wouldn't really matter on these, because they got shoes anyway! They are 90% pure lead and I want to make em really splat when they hit. My goal with PC is to get softer lead to fly faster.

[Echd]

I don't think the one on the top left is going to do much. It says it has zero calories!

[Beagle333]

Okay.... this is going very smoothly. Thanks to BangerJim for recommending that folks get that $6 regulator too! I don't think the reg on my tank would be effective after going through 50 feet of hose.

[bangerjim]

Okay.... this is going very smoothly. Thanks to BangerJim for recommending that folks get that $6 regulator too! I don't think the reg on my tank would be effective after going through 50 feet of hose.

Those look "maaaaaaaaaavelous!"

Good job and welcome to the ES PC gun insanity!

Now you go out there and get those zombies!!!!!!!!!!! And you do it before you cast another booilit, Bob Cratchet.

bangerjim

[freebullet]

I know I've read it somewhere along the way, but how much thinkness does this add?

[MacFan]

I know I've read it somewhere along the way, but how much thinkness does this add?

I'm getting .001 to .0015" added to the diameter with the 4 different powders I've tried.

[Beagle333]

The NOE WFN coated nicely. I think this one is going to be a winner.

The candy coating looks pretty, but I'm doubtful about its lube ability. I'll find out soon.
Fortunately I just have a sample of this paint and not a pound.


Things I've learned today:
1. My HF gun works best at 30 psi using the gauge at the gun. Less, and it tends to let powder build up in the tube and spits out clumps occasionally. This stopped completely when I left it on 30#. Keep in mind though, I don't know how accurate a $6 gauge really is.

2. My coatings added around .002-.0035 to the diameter, depending on color. This was not a problem, as they slid right through the sizing die so easily that I had to look to be sure it was the right one.

3. Do not attempt to cheat and use regular foil. That batch will get melted down and repoured. I was getting 2 batches per non-stick sheet. I got flashing on the 3rd, so started replacing it after 2. This will probably depend on how heavily you coat and how much overspray you have.

4. Changing colors is NOT an easy thing. It's about as easy to change the alloy in your pot, and about as time consuming. I think I'll stay with the HF red. It worked really great. (although many prefer the matte black, but I didn't have any black here.)

5. Now that I have figured out my spacing, I'm going to JB-Weld my nuts. It is a pain to line em up again after every changing of the foil.

[freebullet]

Wow those are some stellar lookin boolits beagle. So it appears you can somewhat control how thick you apply it with the spray on method, that could really be handy.
Has anyone tried running a thicker coating on a undersized boolit? Like a .278 coated upto .309ish.

[C. Latch]

Oops. I just read all 10 pages of this thread. I see a purchase in my immediate future.

[el34]

I'm wildly impressed with your boolits Beagle. Just today I did a few hundred with the NS foil-over-nuts setup. It was absolutely painless, the boolits literally poured off the tray after cooling. But I learned that more than 2x on the same foil is pushing it. Who cares, NS foil is cheap and easy. Like you I decided to glue the nuts. Next time I'll try a block of dense foam rubber backed with something stiff to mash the foil around the nuts with one push.

Today I used gloss black from PBTP and didn't skimp on the powder- better a bit too much than too little- they grew 0.002".

Thanks for the pics, they get right to the bottom line.

And thanks to bangerjim for relentlessly pounding on the HFESPC method and 'specially the non-stick foil.

[xacex]

Oops. I just read all 10 pages of this thread. I see a purchase in my immediate future.

Now go and read the 84 or so pages of the first powder coat thread. Good info and some nice picture in there too. Somewhere around page 50 I posted some 45 hollow points that expand perfect. Those are part of my pet load now.

[el34]

Now go and read the 84 or so pages of the first powder coat thread. Good info and some nice picture in there too. Somewhere around page 50 I posted some 45 hollow points that expand perfect. Those are part of my pet load now.

And learn the diff between ElectroStatic and piglet and epoxy and Hi Tek. The only bad thing about getting the HF ES gun is, well, there isn't one.

[drysound]

Has anyone tried the Sears Electric Powder Coat Gun system. I was searching for a source for additional powder cups for my HF system and ran across an ebay listing for new Craftsman systems for about $60. Looks like these things have an internal fan system and don't require an air source. I have to do my PCing on my back porch and like the idea of not having to drag my 20 gallon compressor out when I want to PC. Just wondering if anyone here is using the Craftsman and if so, what you think of it.

I find the HF gun fairly easy to clean with a little air but would really like to find one or two more powder jars. I'm still experimenting with colors and not having to clean the jars so much would be nice. To bad HF didn't make the sprayer jar the same size as the jars the powder comes in.