Etch primer not for steel panels :confused:
 

I was reading the metal primer tins at the store and they said that the straight zinc metal primer is for raw steel and that the etch primer version was for copper, aluminum, brass, zinc, etc. I notice everyone likes to primer steel Porsche panels with etch. Now I'm confused as to what I should use. Can anyone enlighten me.

not all manufacturers etch and epoxy primers are the same so the do's and don'ts are also not the same . it's always good to read the tds (technical data sheets) to know if the product your buying is one that will work for your needs .
not all brands use the same amount of zinc and other chemicals so you will also find some you have to add a catalyst and some you don't . so will want only one thin coat and others you will need to spray two coats .
you will find with some manufacturers that they will have different etch and epoxy primers for different uses but they are still etch or epoxy based primers .
to pick a heavy zinc based primer for coating non-ferrous metals is kind of pointless as there is no rust problems as you find with a ferrous metal.

yeah what paint system are you using?

You should use the same manufacture from start to finish on your paint job. Mixing paint manufacture products will only cause you pain.