Powder coating made easy

[sofbak]

It arcs very well about an inch. I clean all my bullets in acetone after casting and then let them air dry and then try to powder coat them.

Tried again after cleaning them again..
nothing.. the powder sticks better to the container and teh BBs than it does to the bullets. Trying now in my vibratory tumbler which used to do tumble pretty well.

Hmmm... Based on the details you provided, I'm wondering if something got into your lead pot.... I have no idea what it could be that would prevent the ES charge and still conduct/arc to your gun, but I'm running out of suspects..

I sure hope you figure this out. I'm stumped.

[meaty-btz]

Hmmm... Based on the details you provided, I'm wondering if something got into your lead pot.... I have no idea what it could be that would prevent the ES charge and still conduct/arc to your gun, but I'm running out of suspects..

I sure hope you figure this out. I'm stumped.

Could be powder, could be God only knows what. I turned back to the vibratory tumbler to continue my research. Let it run an HOUR. All the BBs are coated, as in coated well enough to bake. The lead.. hit and miss.

Now I recall that I didn't use to wash my lead in acetone after casting I just would chuck them up and spray unwashed and I never had this problem.. so next set I will try un-cleaned. I have a full set rather than a test set in the tumbler right now. So far it looks like a slightly more even result than just tumbling alone which lead to clumpy results. The BBs pick up the coating better than the acetone washed lead... I am baking a BB just because..

Note the bare spots are something that I have been experiencing with my ES Spray as well and would often have to HEAP on the powder to cover them.

Pic..

[meaty-btz]

Baked..





Color me underwhelmed.. but it does waste less powder than my current ES gun where waste is almost at 50%..

Still I wonder what is going wrong with the powder adhesion as this really is a more recent issue.

[meaty-btz]

One of the issues is my powder is very clumpy and that may be the cause of all my sorrows. Excessive moisture in the powder can make it clumpy and thus cause these problems...

[sofbak]

Baked..


Color me underwhelmed.. but it does waste less powder than my current ES gun where waste is almost at 50%..

Still I wonder what is going wrong with the powder adhesion as this really is a more recent issue.

Sounds like the acetone may be the culprit. I'm not a chemist, but I did find some research abstracts addressing the conversion of lead cations with exposure to acetone. So the exposure seems to have some effect on the charge state of the lead.

You're doing some pioneering work here in the name of PC bullets.. thanx for the effort.

[meaty-btz]

Sounds like the acetone may be the culprit. I'm not a chemist, but I did find some research abstracts addressing the conversion of lead cations with exposure to acetone. So the exposure seems to have some effect on the charge state of the lead.

You're doing some pioneering work here in the name of PC bullets.. thanx for the effort.

If I am altering the alloy with Acetone exposure then that really would explain it. Especially the "zonal" nature of the areas that fail to stick.. hmm

Well next batch I just need to remember not to do the acetone clean and will report back with results.

I can't get through the paywall on those abstracts.. but.. if we are neutralizing the lead ions that would prevent the fields needed for bonding from forming... or we may be creating a charged field that repels the powder.

[Pablo5959]

Stilly,
Here's a pic of my container with .12gr neon green BB's. Sorry but I need to cast some more or I'd show some in there.
A shallower container may help a lot getting the pills out.
If you scratch one while picking, just throw it back in and swirl a bit

Right side pills are sized to .357.
Left side are unsized. This was the last batch and the BBQ got up to 450 degrees when I wasn't paying attention.

[sofbak]

Well, I'm a mech eng. not a chemist, and I'm having to reach back over 30 years to the chem class I took. But from what I remember and what I read in those abstracts, you do want ions-an ion is a molecule with a particular charge polarity + or -, to attract the powder. But I think the acetone is converting them all to the wrong ion state (polarity of charge). Hence they don't accept the electro-static charge from all the shake and tumble activity. ???

Anyway, avoid the acetone. A good thing to know, as I have some lead bullets factory lubed. I was going to try acetone to wash off the lube. I'll find another way to get it off now... IIRC, I read about lacquer thinner somewhere in that cb thread.

[Pablo5959]

Well, I'm a mech eng. not a chemist, and I'm having to reach back over 30 years to the chem class I took. But from what I remember and what I read in those abstracts, you do want ions-an ion is a molecule with a particular charge polarity + or -, to attract the powder. But I think the acetone is converting them all to the wrong ion state (polarity of charge). Hence they don't accept the electro-static charge from all the shake and tumble activity. ???

Anyway, avoid the acetone. A good thing to know, as I have some lead bullets factory lubed. I was going to try acetone to wash off the lube. I'll find another way to get it off now... IIRC, I read about lacquer thinner somewhere in that cb thread.

By the way my last batch was already sized and lubed.
I soaked them in paint thinner for about 1/2 hour and dried them before tumble.
They came out fine.

[meaty-btz]

Well, I'm a mech eng. not a chemist, and I'm having to reach back over 30 years to the chem class I took. But from what I remember and what I read in those abstracts, you do want ions-an ion is a molecule with a particular charge polarity + or -, to attract the powder. But I think the acetone is converting them all to the wrong ion state (polarity of charge). Hence they don't accept the electro-static charge from all the shake and tumble activity. ???

Anyway, avoid the acetone. A good thing to know, as I have some lead bullets factory lubed. I was going to try acetone to wash off the lube. I'll find another way to get it off now... IIRC, I read about lacquer thinner somewhere in that cb thread.

Yup either I am reversing charge or de-ionizing the lead (or altering it's chemical structure to prevent ionization). No matter what that would be a very good explanation.

Pablo is getting some very good coverage with his setup.

[sofbak]

By the way my last batch was already sized and lubed.
I soaked them in paint thinner for about 1/2 hour and dried them before tumble.
They came out fine.

Thanx! Good to know what works.

What was the original color of your bb's? I noticed you mentioned they were the .12 gr weight. The only black ones I saw at wm were twice as heavy, so now this may be another variable in the soup.....

And why the tape measure in your pic? I noticed a little powder on the end and wondered what you were measuring with it.

[meaty-btz]

By the way my last batch was already sized and lubed.
I soaked them in paint thinner for about 1/2 hour and dried them before tumble.
They came out fine.

Paint thinner is different than acetone. I tend to believe the abstracts though I would love to get my hands on the actual papers I do know a think or two about the chemistry of materials.

As with plating, in PC, often, less is more. You want enough to create an ionized particle in the PC that is then attracted to the opposing charge imparted to the target.. but just enough. When designing jigs and stuff you have to worry about the guns power level vs the space between targets or you can create a Faraday Cage about your target and actually prevent powder from entering a certain area.

Just as in plating where you want to use as little votes and amps for longer vs more faster as higher amps creates a more rough plating and it can cause voltage breakdown in the fluid that results in dendrite growths on the plating target.

There is much science to what we are doing. Pablo, what is the humidity where you are at right now? I wonder..

[Pablo5959]

Could be powder, could be God only knows what. I turned back to the vibratory tumbler to continue my research. Let it run an HOUR. All the BBs are coated, as in coated well enough to bake. The lead.. hit and miss.

Now I recall that I didn't use to wash my lead in acetone after casting I just would chuck them up and spray unwashed and I never had this problem.. so next set I will try un-cleaned. I have a full set rather than a test set in the tumbler right now. So far it looks like a slightly more even result than just tumbling alone which lead to clumpy results. The BBs pick up the coating better than the acetone washed lead... I am baking a BB just because..

Note the bare spots are something that I have been experiencing with my ES Spray as well and would often have to HEAP on the powder to cover them.

Pic..

Meaty
For my first try I cleaned about 75 already cast, lubed pills off with paint thinner and threw them in the BB's still wet. They clumped up and looked like yours, then I added more color thinking they may even out. No good, they need to be dry.
Where yours totally dry when you dropped them in the container?
Pablo

[meaty-btz]

Meaty
For my first try I cleaned about 75 already cast, lubed pills off with paint thinner and threw them in the BB's still wet. They clumped up and looked like yours, then I added more color thinking they may even out. No good, they need to be dry.
Where yours totally dry when you dropped them in the container?
Pablo

yup, totally dry. As I theorized above my powder may have too much moisture being absorbed from the atmosphere as humidity is a little higher recently and that would be contributing to the clumpyness.

[Pablo5959]

Thanx! Good to know what works.

What was the original color of your bb's? I noticed you mentioned they were the .12 gr weight. The only black ones I saw at wm were twice as heavy, so now this may be another variable in the soup.....

And why the tape measure in your pic? I noticed a little powder on the end and wondered what you were measuring with it.

The tape is just to show how big my container is.
The BB's are neon green.

Here's what I think helped. This is my tumbler. Don't laugh. It works well.

I'm thinking putting my container in this and let things tumble for 15 minutes helped even out the coverage.
Now don't get me wrong. The plastic container goes in side the tumbler.