Seems like deja vu all over again? VHT is made to go on plastic as far as I know not sure I would recommend it on metal. Now duplicolor metalcast is made to go on metal and I have used it on my previous intake. For something as smooth as a chrome or polished metal I would start with a good prep-clean followed by adhesion promoter and then finally you can start the metal cast. Its only pain so its not going to be as durable as your powder by any means and I would recommend a heavy clear over it after the metal cast. I understand that you want to do something different and as I am pretty sure was mentioned earlier is to just dip them or spend the money for powder. IMO even if the paint is perfect from the start its only a matter of time before it gets a chip and that chip gets bigger & bigger. At that point you now have wheels that are a dime/dozen but now do not look as good = get what you can for them. Yes powder costs more today but will save you more in the long run as long as you don't get some crazy color no one wants. No you will not get your powder money back out of them but you also will have an easier time selling custom powdered wheels.