My first powder coating was highly successful and worked out very well. They worked exceptionally well too. I was tickled pink …. actually red.
So I decided to give some bullets for the 45-70 a try. I did a quick casting of Lyman 457-193 (Beagled) in Lyman #2. These drop 0.460" as cast. I was guessing the PC would add 0.002" - 0.004" to the diameter and I would size them to 0.459". Everything worked out as expected.
I washed the bullets in acetone to get rid of any grease or oil that may have contaminated them. Probably unnecessary, but I felt better for doing it. I then put them out on a paper towel to dry for 30 minutes while I set up the oven and started it warming.
I use the Ziploc 2 cup twist top containers. Added 4 layers of black pellets from Smoke and two level tablespoons of his John Deere Green. To help with static I hold the container in a pair of military wool gloves. Swirl for 30 seconds; shake up and down for 30 seconds PLUS turn the container on its side and tumble for 60 turns while rubbing it with the gloves. When I opened the container I would grab the bullets with forceps, tap the forceps against the side of the container to get rid of excess powder and stand them up on the oven tray which had been covered with non-stick aluminum. I'd repeat until there were 50 bullets spaced in rows about an inch apart on the tray. I could probably crowd them more, but I'm still learning.
The oven thermometer is reading 400°F so I open the oven, put the thermometer on the tray with the bullets, slide the tray in and close the door. The temperature has, of course, dropped so I watch until it reaches 400°F again and then start a 20 minute cooking time. When they were done I turned off the oven, opened the door and let things cool down.
As I was putting the bullets through the sizer I noticed that the PC coverage seemed blotchy and thin in areas. After I was done I looked at each carefully and even found bare spots. I decided that I was going to re-coat.
Because the bullets had gone through the sizer I started with a good acetone wash to get rid of any residual lube that may have been in the sizing die. THEN, THIS TIME I put the bullets in the oven at 150°F for 30 minutes to pre-warm them AND get rid of any acetone. Then I went through the same coating and cooking process described above.
Half of the bullets came out with what I can only describe as "blisters". You can see them very clearly on the bullets sitting upright in the Styrofoam holder. At first I thought it might be due to acetone being trapped in the first coating. But 30 minutes at 150°F should have evaporated any acetone. The PC sticks, doesn't chip or flake. They just have blisters which will play havoc with the BC. (I guess a little sandpaper will smooth things out - my tongue is in my cheek).
Any ideas what happened? Thanks.