Clamp pedal spindle in bench vice, gripping on the flats..
If you put enough torque through the crank, doesn't clamping a narrow piece put you at risk of breaking the bench vice? ISTR people trashing vices by clamping a freewheel removal.tool and using the rim as leverage.
If you are able to break a vice with the mechanical advantage of a mere bicycle wheel, then the vice is Utterly Wet and and a Weed, and should be Discarded.
er, once the vice is broken, you don't have that much choice. If you do the sums, small flats on a tool in a bench vice plus high torque = several tonnes load; far more than you would be able to exert by simply tightening the vice. Cast iron vices are mush more vulnerable to failure through abuse than cast steel vices. Cast steel vices are more money to buy, of course.
I can't remember if I have mentioned this already but once you have decided to sacrifice the pedal spindle, welding onto it can be a good scheme; this gives you something bigger to hold/hit and the more localised heat frees the joint off in a way that applying a more global heat source cannot manage.
The other thing I didn't mention is that the chances of the crank thread not being damaged can start to get small too; this being the case if the pedals are expensive ones it can make more sense to cut the crank off the pedal instead. This is not at all difficult or time consuming to do; a couple of cuts with a hacksaw and a couple of good hits with a hammer usually does it. No matter how corroded the thing was it should be possible to clean up the pedal spindle thread afterwards.
cheers
