I posted this on the 16th but it didn't seem to work. I am trying to take out 3/4 10 bolts out of a rusty cast iron keel in a sail boat. The bolts are about 3 inches in the iron and three inches in the fiberglass. I was thinking for maximum removal force to drill and tap 1/2 or 9/16 left hand threads into the bolt that I cut off the nut of, because the hex head is so rusty that yoy can't get a socket on it. I would need at least a grade 8 left handed bolt to be able to force it out with a 1/2 electric impact gun. I would first drill a 1/8 hole to the end of the bolt and then tap in a 1/4 pipe fitting so I could put in kroll oil and then force up the threads with 175 psi air pressure. I can't use heat or weld on the bolt because of the fiberglass must be strong. I have the following questions.
1 Is this the strongest way to take out a bolt?
2 Does anybody know of a unscrewing divice other than ezyouts and the other square one that don't seem to work on extreem conditions.
3 If you use a left hand bolt will you be able to get the old bolt off with out turning it off? Don