On Mon, 2 Dec 2019 21:19:08 +0000, John Rumm
wrote:

You could also try some thermal shock - hold a bolt with pliers, and
heat the end blow torch and then push it onto the end of the screw for a
bit before trying to turn it.

Or the other kind of thermal shock: "rust shock" is (a class of) sprays tha
combine pentration oil with a freezing spray.


Thomas Prufer