Originally Posted by MudPie
Before going to destructive techniques, have you tried chemical penetrants like WD-40 or penetrating oils to "dissolve" the bond? Some of the claims on cans of this stuff are pretty bold...
Ooops, I guess I should've read Shelton Brown's hints first:
"Aluminum seatposts frequently become stuck by corrosion also, and penetrating oil is almost useless against aluminum oxide. Fortunately, aluminum oxide can be dissolved like magic by using ammonia."