Just went and used paint shaker at work. The primer stirred up great. It is PPG 512X310 urethane compatible epoxy composite primer. Should be just fine on steel. I will take a sample of steel sheetmetal, rough it up, and apply some of this primer. Will do a tape pull test for adhesion maybe sand on it a little when its dry to see how well it adheres to steel before spraying the car with it. If i cant use it, i have a buddy with a corvette who can.