David Lang wrote:
(polishing)
I was trying to avoid the 'by hand' method. I saw on The Caravan Show the
other night someone mirror finishing aluminium with what looked like an
angle grinder, but the pad was at right angles, The pad appeared to be
discs of cloth stitched together.

That's a rag buffing wheel, I have no idea what it's mounted on - note
that your grangle winder whizzes around at at least 10,000 RPM, so it
will be a bit tasty on aluminium. What about a car polisher? You can
get a thing called a "Power Devil car polisher" if it's no good or
breaks, take it back!