I am about to get my fixed gear powdercoated, and would like to cut off the unused water bottle mounts, downtube shifter mounts, cable mounts etc etc (ie any memory of it having gears).
Is this easy to do satisfactorily or am I likely to end up scarring the frame? Should I approach it with an angle grinder or hacksaw + metal file then sandpaper??

Thanks

I used just a file to do this on my first fixie (low-end 80s ten-speed frame). If you're getting it repainted, you probably don't need to sand it very carefully... I doubt it will show under the paint.

On my new fixie, I haven't removed any of the unused braze-ons or cable guides because it's a nice enough frame that I might want to restore it to geared use someday.

I cut mine off with a Dremel followed by a file, Bondo, emery cloth, and progressively finer sandpaper. I'm going to disagree with my friend about surface preperation. Any surface that isn't perfect will show up under your new paint job.

Thanks for the correction! As I said, the only bike I did it on was a cheap old thing, and the black nail-polish cover-up looked flawless to my eye

One thing I would add: how are you going to remove the water bottle mounts without leaving holes in the frame? I suppose you could fill them with solder and sand down the excess. Better to just leave them alone, I would think...

a dremel tool works nicely