This hint works for any stubborn fastener - for each 1/4 of undo ,do it
back up an1/8th turn. This stops "balling up". I believe it actually creates
balls as opposed to wedges of material. Keep lubricating it from both sides
if possible during the process and the occasional blast from a blowlamp will
help. You can wrap the pedal spindle or whatever in a cold wet rag to reduce
the rate of expansion if things get really serious. In this case hold the
spindle upside down, 2 reasons, lube goes down into threads and water on
spindle rag doesnt get onto heated crank. Good luck and perseverance.
Mark Stevens in the Hub of Highlands. (We have a holiday let!)