what do you mean, i am using the proper tool?
it gets the paint away and rust, then soon as i see bare metal im done

also have mini wire brush attachments for my dremel too

I'm trying very hard to bear the SinBin in mind in reply, James...

No, you are not.

You are using a grinding wheel to remove paint & rust. A grinding wheel will remove solid steel as well.

A steel wire brush - preferably a knotted one - will remove paint & rust, but leave the solid steel alone. (A brass one is too soft)

2cv panels are thin. Be kind to them.

He's right, you know ...

ahh you mae sense now

ok i have a brass and steel one, for the dremel, i found that on the dremel the wire brushes only scratch the paint, and that the grinding ones are just right, from my own expereince so far (i know its not the best way considering the thiness of the panels but the grinding disc if used carefully is ok . on the other hand i get what you mean about the wire brushing, i dont doubt that your right, just that i find the wire brush isnt good enough on the dremel

i have a set of these
http://cgi.ebay.co.uk/8x-wire-brushes-minidrills-dremel-2-3mm-shank-/390245354583?pt=UK_Hand_Tools_Equipment&hash=item5adc6f8c57

both types, ive only used the ones that are circular, and they seemed a bit feebel, and a normal sizedwire brush attachment obviously to large for delecat operations, in previous grinding rust situations, ive stopped the minute rust is gone, which is literally instant, i know im thinning the panel A small amount, but when i do it i do it so little its not measuarble,

however next time adrian i will try using the wire brust attachent again and persist (wich one in the ebay link is betteR?) and hopefully have good results

Try the brush in something with more grunt.

will do, the dremel has a speed adjuster, i have it on 18,000 rpm all the time but will be bit more fierce

Have a think about the diameter of the brush vs a "proper" drill-mounted knotted wire brush - and what that does to the velocity of the wire at the point it contacts the paint - and the sturdiness of the wire.

Dremels have their place, sure.

true, thought about that, but in small delicate places, doing like a cm squared, a huge wire brish isnt neccasary as itll do about an inch squared

hmmmmmmm if it were me I wouldn't bother doing a 1cm repair. Surely it would be better to remove more and get out ALL rust and judging by my attempts with filler and painting, I'd prefer a little rust bubble to a terrible paint match

well its only when its like a stone chip and its rusted or a tiny tiny bubble, so i attack it!
my paitn matching isnt to bad, its not brilliant, but its more attractive than rust if i may say so myself