HotCoat

I was the tech guy at Eastwood and did lots of powder coating and helping with problems. The biggest thing to remember is ...when doing any types of metals, ESPECIALLY aluminum or cast iron, MAKE SURE YOU PREHEAT EVERY PIECE TO 400 DEG,F FOR AT LEAST 30-40 MINUTES!!!
Those porous metals must be preheated to allow out gassing to occur. If you do not preheat, what will happen is you will get the outgassing on the part after you powder it. It will appear as tiny air bubbles in the powder. It is a good idea to actually preheat evey part you will do, you never know how any metal will react after it is powdered. The parts also MUST be cleaned to within an inch of their life. By that I mean, either bead blasted or stripped, then wiped down with a cleaner that won't leave a residue.
If you are going to clear coat a part after putting on a color, it is also advised to heat the already powdered part to at least 200 degF, then bring it out , turn the oven up to 360degF, and apply the clear and put back in oven at 360.
As with anything new to someone, practice, practice and more practice. Do not start powdering parts right off the bat. Get some old metals of all types and experiment first. This is very similiar to spray painting, and with that you will get some dry spray, over spray, some that doesnt melt correctly, etc......so like I said....PRACTICE!!!