Powder coating questions

Kiwi cop

Kiwi cop

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I thought I had a supply of pre-powder coated .452 and .356 powder coated projectiles, but it appears they may not have been coated at all, so after procrastinating for far too long I have finally decided that I need to get my lead projectiles powder coated.

I have the powder, projectiles and some shakers/containers, now I have some questions.

1. Will a bench top air frier do the same job as a toaster oven? I have a brand new one that was given to us and we don't need in the house, so can I repurpose it?

2. What is the "ideal" temperature? Locally guys set it at 200C/430F. Videos range from 300 - 400 F.

3. I have been told that the projectiles will need to be cleaned in something like acetone to remove any oils from handling, but none of the YouTube videos on powder coating mention this. Does anyone clean their projectiles first?

4. How many coats are required? Videos say only 1 coat but I have been told I will need 2.

5. What is a reasonable number of projectiles to coat at a time? It seems that most simply "estimate" the number. I have my projectiles stored on batched of 500 so can I do 150-175 at a time?

Thanks in a advance.
 

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I think much is trying and seeing what is to your satisfaction.
1. If it will make the temperature, it should work.
2. Does the powder have a recommended temperature? If not try some batches at escalating temps, much like load development.
3. Degreasing will likely improve adhesion of the coating, but, again, you may want to try with and without degreasing to see which does best.
4. As above, evaluate after one coat and apply a second if deemed needed.
5. More projectiles will require longer to heat. Try 150 or so and evaluate the time to heat and the results. If time is not a real factor, larger batches may be do-able.
 
For many of us, it has been a lot of trial and error to get to the point where we can consistently produce properly coated bullets. Can you post pictures of what your bullets look like now? I am not sure what "pre-powder coated" is. If there is lube on the bullets, then absolutely that will have to be removed.

For me, the hard part was getting enough static built up to get the powder to stick to the bullet in the prep stage. There are many methods, but I tumble mine in a peanut butter jar with two barely inflated (NO WATER) water balloons. Water balloons seem to be the right size and thickness. How much powder-vs-bullets will be based on what size container.

Once you get powder sticking and coating the bullets well, time to go into the oven. Again, it will be trial and error. Ovens are not all the same. But some where in the range of 350*-375* for about 20 minutes will be close.

I bake only a single layer at a time, and am not inclined to stand them up on end, but I do shake the tray as I slip them in the oven to get the bullets to spread out.

Search for Elvis Ammo on youtube. His instructions helped me as much as anyone else. Good luck, and don't despair if you fail a few times along the way.
0011 share hensley gibss 10mm 200 gr oct 2021 powder coat fun (28).jpg
 
I use isopropyl alcohol to clean before coating, but if your bullets are lubed, it’s not worth trying to “unlube” them. I found someone who sold “as cast” bullets with no lube. I don’t tumble, I use a Harbour freight powder coating gun and do one coat. I cook at 300 for about 20 minutes and get good results. The air fryer should work good if you use the “bake” mode. You don’t want the convection fan running, it will probably blow the coating off the bullets.
 
Maybe add a little garlic and Ginger to the mix to help out the old
"Burnt rubber" spell ?

Just kidding.

I'm just jealous, since I don't coat.

If I did it would be sky blue and hot lips red !!
 
From what I've read 200°C or 392°F will be what you need for powder coating.

I would worry about the fan inside a air fryer upsetting the powder coating before it cures but only trying will tell.

As for how many at once, I would think whatever will fit on the tray/trays without crowding.

Good luck, let us know how it works out.
 
I've never cleaned any of my "as cast" bullets. Never had any issues with oil from hands, ect.

I put black airsoft bb's in a standard #5 bowl and use the shake and bake method to coat the bullets. The bb's cause static and ensure the pc sticks to the bullets.

I use 1 qt size containers to coat with that have 1 cup of bb's in them. To that I add 3 tablespoons of powder and shake +/- 50 bullets to coat at 1 time. Typically I shake the bullets 50 times then turn the container over do another 50 shakes. Then I put the coated bullets on a rack and add another tablespoon of powder and do 50 more. Eventually you'll have enough powder in there and you'll be able to do bullets without adding powder.

I bake my pc'd bullets @ 400* for 15 minutes. Used to bake them for 10 minutes. But 10 minutes was on the edge of under curing the pc. I put as many coated bullets as I can fit on a cookie sheet covered with either non-stick aluminum foil or parchment paper and bake them. I'm using a small oven so I can only put 1 sheet in at a time. If the oven was larger or had racks I would use them/fill them with multiple cookie sheets.

It only takes 1 coat to cover the bullets.
xHUCNJn.jpg

lZyBjGD.jpg


Recovered bullets from the berm, the coating says on.
JMxvOFA.jpg


Was testing alloys for elasticity using a 308w as a test bed. The slower bullets shattered/were too hard. That 2300fps bullet that bent was a 230gr cast bullet/50,000+psi load.
9TAAbA8.jpg


This bullet was baked for only 10 minutes. It's a hollow based swc that I used a forester's hp tool on to add that huge hp. It was shot in a snubnosed 44spl/1000fps+ load. The hp was impressive
FTFbMo6.jpg


A side view of that same mushroomed bullet pictured above. As you can see the hollow base also expanded and the bullets body compressed (as it should). But it also clearly shows the pc coating failed/came off the body of the bullet.
Swqedh0.jpg


Bumped the cooking/curing time from 10 minutes to 15 minutes and there was no more under cured bullet coating.
 
I bought a new toaster oven for the house and repurposed the old for powder coating. I set my temp at 400 degrees and bake for 15 minutes. The results have always been perfect. If you air fryer is 400 degrees, I would imagine it would work well. An air fryer is nothing more than a small counter top convection oven. As someone else mentioned, the forced air may or may not disturb the powder. Will have to see.

I have always PC'd ones that I just cast and I am careful to keep them oil free while handling. However, if you think your boolits may have oil on them, acetone or the like should take care of that. Be sure to let it dry completely before powder coating.

Rosewood
 
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I have seen powder coated bullets that were done in Clear and some done in Gray ... and I swear they just looked like unlubed / uncoated cast lead bullets .

I don't powder coat but I thought the Clear and Gray colors looked a lot better than the Red color that makes your old West gunbelt look like you packing a lifetime supply of Lipsticks !

Are you sure your bullets were not clear coat or gray ... might be worth a check !
Gary
 
I went to Goodwill and bought a good toaster oven for $17. I set it to 400. I have seen anywhere from 15-30 minutes. I just kinda eyeball it, usually about 20 minutes give or take.

When you are told a #5 bowl what is meant is a recycle symbol 5 container. You can get them in the food storage area of Walmart or whatever. Usually comes with a screw on lid. The black airsoft BBs are supposedly the best for static. You can also use a balloon in the container. I blow it up just a little and tie it off. I was only able to find the white BBs so that is what I am using.

I have used Harbor Freight and Eastwood powder coat. I also got a pound of prismatic and mixed it with Harbor Freight and it still worked well, probably better than they did separately.
 
FWIW, if you live in a college town when they shutdown for
the summer you can hit up the thrift stores and get toaster
ovens for a little bit of nothing. I got mine for less than $10.00
in 2017.
 
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read this a while ago ... figured I would pile on.
The air fryer might not work out since it incorporates airflow.
PC isn't paint, it's dust held in place with static long enough to get baked in place.
There is not an ideal temperature. the various available powders have different temperature ranges and cure times. Start by using as directed on the label, in accordance with the prophecy. The gods should then be appeased.
Cleaning of the projectiles ... There has been some long standing confusion about this. Powder coating is not the only game in town.
There is another product called hitek that is a two part liquid that is baked on as well. This stuff is notorious for being finicky about clean substrates. Powder coating is a different matter. It does not require cleaning from things as slight as hand oils. Unless you swim in 10W-30, it won't be a problem. There are exceptions, such as stripping traditional lube from a batch of bullets. (boil, skim, dry brakeclean)
Number of coats is application method and powder dependent
The airsoft BB shake and bake method may require more than one coat if the powder does not lend itself to the process as well as others. Some are a bit difficult.
There is also a slurry method where you can mix with acetone and tumble coat. this can mitigate issues with stubborn powders.
Actually investing in an electrostatic powdercoating gun trumps everything. However, this is best left to those who are dedicated to casting rather than one off batches or occasional users.
batch size ... This is a function of oven size and your patience.
If you're willing to put 10,000 on sheet pans and put them in an oven large enough, there's nothing stopping you.
 
I saw it mentioned one time. Kiwi Cop is situated where (like the rest of the civilized world) temperature is measured in degrees C. So most are really using between 200 and 220 C. Dave_n
 
gwpercle said:
I have seen powder coated bullets that were done in Clear and some done in Gray ... and I swear they just looked like unlubed / uncoated cast lead bullets .

I don't powder coat but I thought the Clear and Gray colors looked a lot better than the Red color that makes your old West gunbelt look like you packing a lifetime supply of Lipsticks !

Are you sure your bullets were not clear coat or gray ... might be worth a check !
Gary
Click to expand...

I use clear for this very reason. Bought from a guy called smoke on castboolit forum. Works way better than the red I tried from HF.
 
For what it’s worth here’s my experience and what I do:
- use cheap toaster oven 400F for 20 min
- tumble the bullets in an old cottage cheese container, no BBs needed. Apparently builds enough static to make the powder coat stick well.
- You’ll figure out when it’s too thick or too thin. You’ll want to have enough powder to give solid coat but not too much to where the bullet design looses its shape… well defined bullet.
- I’ve found Elvis Ammo’s youtube videos pretty helpful overall but even he says what works for one person might not work for the next. Trial and error
- I line the tray with non-stick foil for best results.
- I try to limit the number of bullets on the the tray to where they’re not piled on but spread out… touching each other is ok but will require separating the ones stuck together after they’ve cooled somewhat.
 
I use a cheap toaster oven at 400 F for 20 minutes. One coat only. I try to not have the bullets touching while curing but sometimes they do without any huge problem. Shake of the excess powder or the coating will be to heavy. I have never degreased but coat right after casting and handle the bare bullets with nitrile gloves.
IMO the secret to good coating is good powder to start with. I use Eastwood. A buddy tried HF and others with poor to just so so results. It goes a long ways so just buy good powder to start with.
I tumble mine in an old plastic ice cream tub with a good sealing lid. No BBs or anything. I shake them a minute or so and the powder stick OK. I think you can get the powder to heavy and I have the bullets would not size without deforming.
Powder coating works but I still lube some bullets with better alloys but it shines with softer stuff at least for me
 
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