acid dipping rust removal

I recommend neutralizing the Muriatic acid with a dip in a baking soda/water mix and then spray phosphoric acid on it as it will leave a zinc coating behind. Check it out at : http://www.eastwood.com/rust-protection-done-right

I used Muriatic acid on a boat trailer axle and after washing it off, I painted POR15 on it without neutralizing it. But the POR15 just lifted off in sheets within a year as the axle continued rusting underneath it. I think that the Muriatic acid prevented the POR15 from getting a good bond on the steel.