[qrp-canada] antenna problem

[Bruce Rattray]

I'm trying to take the reflector apart from a 20/15/10 mtr yagi tribander -
this yagi has been up on a tower for many years - where it should come
apart, the pieces of aluminum tubing seem to be "stuck" - oxidation? - I'm
looking for ideas on how to take this joint apart please - one piece of
aluminum is slightly larger which allows the smaller piece to slide inside
the larger piece - 72 Bruce ve5rc.