No, I agree with what you said but it will be the time frame between the sealer and the primer.. as previously mentioned, it is usually somewhere before 7 days.. I am going to be way past that window. .. I have not seen much dealing with this sort of time frame.
I do not understand how there would be any fly in ointment. You have to cut back to bare metal and remove whatever primer is used to weld. And after done welding recoat with epoxy or whatever and then filler or 2k.