I have did both the POR 15 and powder coat on frames. POR 15 needs to be top coated. I have been using an epoxy primer followed by PPG paint (color depending on project).

I have had great results.

The Powdercoat is the best route based on cost and time. (It was faster and cheaper to have a frame powder coated after I compared all the costs)

I used POR 15 and their chassis black on the sub-frames and suspension for my Audi and VW back in 2006, spraying the product after sand blasting There is rust showing thru in areas.

So, my conclusion is sometimes it works really well, sometimes it doesnt, however I have had the best results with POR 15 when I top coated with Non-POR 15 product.

The problems we face today can not be addressed at the same level of intelligence we were at when we created them - Albert Einstein Or with the same level of $ - Me