I was riding around on my bicycle and found a Bombardier jetski or seadoo manifold sitting on the curb with a free sign on it. I wasn't sure it was cast aluminum, but the bung welds looked like aluminum TIG beads. This looked like it would be very useful for aluminum casting, since it would be the correct alloy, and the price was right. The only thing that I'm worried about is the brilliant purple coating. The manifold had a thin layer of carbon black inside it, so it must be an exhaust manifold. That means that the coating is probably something like Cerakote. Is this safe to break up and melt in a furnace without gassing the whole neighborhood?