Okay, this is my second time powdercoating. I did about 40 Harley parts off mine and my buddies bike. Everything turned out great, but I had about 4 parts that came out with runs. I was using the Mirror black powder. I preheated the parts at 400 degrees for 10 minutes. I powdered them and then cured them at 400 for about 12 minutes. Should my temp be lower or time cooking be shorter?