Aluminum Prop Dings

Filing or dressing out prop nicks is a job for a licensed
mechanic, since there are legal specs that must be adhered to, and the
prop manufacturer has more dimensional limits that need to be checked.
They learned these things the hard way; don't you go doing the same.
The right sort of nick, in the right place, given enough time in
operation, will result in a crack that could see a chunk of prop
disappear, and the imbalance could tear the engine off the airplane.
The airplane will not glide with its engine missing, so nicks need to
be taken seriously.
I've seen some badly repaired nicks that actually make the
prop more likely to fail.
Dan