All I did with my truck frame was marine kleen acid cleaner then pressure washed it, put in the garage over night to dry. The next morning I scraped it with a putty knife to get the scale off and painted it with POR-15 2 coats with a brush. It came out amazing. I have used POR-15 on my dump truck frame and inside the dump body and I have no complaints. A friend of mine is building a C-10 de greased the frame used pro prep primed it and painted it with a gun after sitting out side on black top while working on the body it started rusting again now he wants to sand blast it and use POR-15. I think paying someone to sand blast a frame and then paint it is a waste of time and money when there are products out there that you can use to paint over rust and I think looks great. On my frame you cant even see a line from a paint brush its almost self leveling.

A friend will bail you out of jail, but a real friend will be sitting next to you in the cell saying we really F*****up this time.