PrecisionMachinisT wrote:

Get it nice and hot, then spray the crap out of it with WD40

WD-40 will only create a cloud of smoke and waste time and heat. Heat
the bolthead to near glowing and then apply beeswax to the joint.

Keep adding beeswax until it has had time to soak down the length of the
bolt, while still hot, turn in the direction to tighten bolt before
attempting to loosen it. Remove bolt.
Rick