Helicoils!!!! (Removal from deep holes)

[Jonny]

Removing helicons with the Helicoil flat blade is the first step. Failing that my approach is to grind a small chisel and drive it in-between the Helicoil and the old thread. Then pry the end out to where it can be grabbed with a plier. From there pull the old helical out stretching it and leading it away from the parent thread in order to save the base thread as much as possible. By pouring straight out the base thread will be cut more than necessary , thereby weakening it.
Helicoil also makes oversized helicoils to repair holes that have had their I.D.'s enlarged by this extraction method.
Be persistent and good luck.
Jon