Q. Is there a way to finish the inside of bare aluminum panniers so they don't go black?
A. "The best solution I've seen is to use a home product like drawer liners with adhesive backing. Another approach is a very thin outdoor carpeting material with some adhesive. The advantage of using carpeting is you end up with a very slight amount of cushion for the contents of the box." Kurt.
Q. Can I paint bare aluminum panniers to prevent the oxidation that makes them go black?
A. "I've got some personal experience with spray on "clear coat" paint. It didn't work well at all... the contents of the pannier very quickly wore through the clear coat in a lot of spots so I had oxidization on the panniers as well as the rubbed off clearcoat paint. It was pretty horrible. The best solution I've seen for lining panniers to prevent the oxidization issue is with clear (or colored) shelving contact paper. It's easy to use, fairly inexpensive, very durable and holds up for a long, long time. Heath.