"Michael Bushey" wrote in message
. ..
How do I clean a pitted aluminum extension ladder that is so bad it is
hard
to slide the two sections up and down?

Sand the worst of the rough stuff and spray it with WD40 (Go easy as you
don't want to make the rungs slippery).

If the corrosion is really bad, you might have lost some structural
integrity. Salt water/air are tough on aluminum.