Koons wrote:
I have a rusted handrail that I would like to renovate and then most
likely have reinstalled by a professional. Would this be a job for a
welder?

But meanwhile, what should I do? I assume I need to get a drill/sander.
I own a DeWalt 3/8" drill with max RPM of 2,500, and my understanding
is that this isn't good enough for the sanding attachment required.

After the sanding issue is taken care of, is there any particular
treatment required before applying a fresh coat of paint?

http://www.zero-rust.com/zero-rust.html is one option, followed by two
coats of finish paint.

Another option would be to have the railing galvanized before painting.
You could bring it to a shop, or use one of the mil-spec cold
galvanizing paints.
http://devcon.com/devconfamilyproduc...115.0&catid=21

R