Polishing the plate is a little more time consuming to say the least. Because
I did a mirror setup, one chassis is flipped upside down.
So, on one I had to sand past the brushed finish and one I did not. Getting
the brushed finish out is a PAIN.
I start by wet sanding them using a sanding block with some 220 grit to remove
the finish and then some 320 grit to smooth it out.
Doing this in stages, I next used some 400 grit and them some 1000 grit (take
your time and let the paper do the work).
To get a really mirror shine on this soft aluminum I did not use the electric
polishing wheel. This was all done by hand.
The electric wheel would actually leave marks you could see, so I used the 1000
grit to get that out and went back to hand only.
I finished with some SimiChrome metal polish and a soft towel. Doing a section
at a time and then a final over the entire surface.