I posted this over on the HAMB.
The method I have used is to weld a washer over the bolt and then a nut on top. It usually takes two trys ea for me. It may be the heat treat of the bolt. It has always worked.Do not get in a hurry. Gentle back and forth is the way to go.
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I saw something on wax to loosen rusted bolts and desided to try it. I had a column drop and the pinch bolt was so rusted you could not see the threads where they were exposed. I heated the area a couple of time and just for curiosity, melted some wax everywhere it could get to the bolt. It sat overnight. The next morning I built up the head if the bolt and welded a washer and nut to it. I put Vice Grips on the nut and was prepared for a lot of heating and wiggling. The vice grips swung around. The bolt was not even finger tight. Completely loose. The threads in the drop and the bolt are fine. I am amazed.
