What process do you use for the powder coating? How many can you coat in a batch?
I use the shake an bake method, I do my coating usually outside in my building but sometimes I have to do it in the house if the humidity is too high an bake/cure on the back porch, I like the humidity to be around 40% or lower as it helps create static when the air is dry.
I start off with a container like this one as I've found it works the best for me. They are just recycled #5 plastic containers and lids that we get takeout in from the Chinese restaurant but just about any #5 bow with a lid will do.
I fill the container about 1" deep with these plastic beads you can get at any Walmart or craft store cheap. You can wash them off and reuse again an again if you want to switch colors or just buy enough to have several setups with different colors.
I put about a 1/2 TBSP of powder in with the beads and shake it up for about 30 seconds to get everything mixed well, you may need to add more powder but I only add about half as much 1/4 TBSP as too much can make the powder clump on the bullets, you just want a fine coat. As you can see the powder is already clinging to the plastic bowl by the static generated.
Then I add my bullets usually about 50 to 75 at a time depending on size and weight and hold the container like this in my hand an swirl everything around for about a minute sometimes less, there is no real correct way to do this you just swirling everything around.
After shaking I open the contain and inspect the coating an if I happy with it I use a pair of large tweezers to remove each bullet and stand it up base first on non-stick aluminum foil dull side up, some use silicone baking mats or parchment paper, I just prefer the foil. Bullets are then place in my used convection toaster oven which is verified via oven thermometer at 400 degrees for 20 min. While those bullets are curing I get the next batch ready to go in the over as I have two baking trays and can get around 150 bullets on each tray so in general your only limited by the size of the oven or how many you can get on a tray at one time. I can easily do around 300 to 400 an hour once I get the first batch going.
After the bullets have cooled they are ready to be sized and gas checked as needed.
Another point I should mention is that if you cast lead bullets and you use water quenching to add hardness to the lead alloy the powder coating process will anneal the lead and affect the final bullet hardness even if you water quench them a second time after coating. It basically goes like this.
1. If you air cool your bullets when cast then PC them an allow them to air cool again the second time there is no change in the as cast BHN of the bullet.
2. If you air cool your bullets when cast then PC them and quench them right out of the toaster oven they will gain a hardness of about 75% over the as cast BHN.
3. If you quench your bullets out of the mold to begin with then PC them and allow them to air cool they will soften around 50% from the original first quenching BHN.
4. If you quench your bullets out of the mold to begin with then PC them and quench them right out of the toaster over a second time you only loose around 15% hardness from the first quenching.
I either follow steps 1 or 2. I either just cast my bullets from an alloy of the hardness I want to begin with and air cool them when cast an after powder coating I let them air cool again or I cast them from an alloy that responds to water quenching ie wheel weights powder coat them and quench them right out of the toaster oven which give me and increased hardness of around 75% which is fine for my needs.
