etching primer question for m/bike tank

[rocketphil]

Hi
Ithink this is a very good site ,straightforward and very helpful if you are into doing up bikes or cars and have used it a lot.
Anyway I think I know the answer to this question ,it entails lots of work so being a basically a person who doesnt want to create unnecessary work.....
I have sanded down a tank which had very good paint on it down to metal,filler and primer. I believe that etching primer should go on bare metal and not the filler but I obviously dont want to dig out good filler and get rid of all existing paint,it would take days.!!

so what do I do??

Fastphil

 

[langy]

I prefer epoxy primer as you can fill on top once keyed.

 

[steveo3002]

just blast it over the filler , no probs there

its needed on bare metal (or epoxy as above) but wont cause any probs over sound filler

 

[paintpot]

most two pack primers dont need a etch primer.etch is usually used on aluminium or galvanised steel panels,where the galvanise has been removed.