We've used POR-15 on countless projects with no problems, I've got it on my frame connectors, scuffed it up good and painted over it. My uncle builds full chassis and coats them with the stuff, it dries HARD and lasts. side note don't get any on your skin and wear crappy clothes when using it, if you're under the car and have a garage floor you care about cover the floor in case of drippage.