Re: Cant get the old primer off
I agree with tooljunkie. Scuff whats left real good with scotchbrite and paint it. Any primer that hangs on after chemical stripping should make a very good base.
I don't even strip it unless I have to as decent factory paint is as good as any primer you can apply at home once it's scuffed properly.
If more is better, then too much is just enough.
If you can't afford it, build it yourself.