Long story, but I'll make it short - the saw collars on my Belsaw M-14 were exposed to rain for a long time and got rusted. To re-machine them, do I need to take off the mandrel? Or, can I remove the "fast" collar by heating the collar and cooling the arbor? How much taper should there be on the bearing surface? I see the numbers .002 to .003 mentioned in Lunstrum. Is that what I should try for? Thanks!