NEED HELP!! fork pipe is "rust-bonded" to stem
i was taking apart my KHS gransport and discovered the fork piping is rusted onto the stem piping. i unscrewed the stem bolt and its broke on me a little below the threading. i put the bolt back in a hammered the wedge down thinking it should release it. the wedge went down completely and i still can't pull the stem off the fork. i figure its pretty rusted on considering i got it from friends backyard having been sitting through rain and sun for years and years.
i tried all i could.. twisting and pulling to get it loose.. usually works with the other bikes i worked on (feet on the handlebars and twisting the fork with my hands.. haha!) .. using WD40 and hammering it loose, even took it to a bike shop and they couldn't even get it loose.. clamps and all.. it never budged.
now im gonna try some PB spray ("Blaster" PB penetrating catalyst) its for rusted nuts, bolts, pipe threads, etc. not sure if its really gonna work.
do you guys have any opinions on what i should do or try?