[zpaintman]

the primer in question is an epoxy based primer.It is used on bare metal because it has tremendous adhesion.It also stays slightly pliable as to resist rock chips.Dodge uses this primarily but other companies do as well.Unfortunately trying to strip it is a pain.Strippers make it gummy if left on too long and it will tend to clog sandpaper quickly.Heat is the best option here but be careful of the fumes and let it bubble up and dry and it should be a little easier.Hope this helps.