Yes I bought a right angle die grinder and a 3" sanding disc earlier today, used 36 Grit. Works great I did some more welding and grinding and haven' t managed to completely destroy anything yet. Warped the panels a little bit, but a little bit of hammering straightened things right out. Still more to do on this part of the fenders rough still. The back side needs a bit more welding. It's mostly done though. More pounding, welding, grinding tomorrow. Things look rougher in the photo, than they really are, but still not that smooth, I guess a little BONDO is in my future.
Already learned more than a couple of things not to do and believe it or not my welds are getting better and more consistent. Hoping the other side will be better!!!!!