thank you mm for an excellent article on the mechanics of this problem.i read it carefully. getting back to the anti seize issue- have never had a problem with using it for its intended purpose on threads, except on sparkplugs once. it seems the protective coating does wear off or burn up when used on plugs which have a very long change interval. older tanks used to have a plug change interval of 10-20k. but on newer vehicles the intervals are much longer, up to 100k in many cases. most of these have aluminum heads and steel plugs and as you know these metals fight each other. all ive seen recommend use of anti seize on the threads. recently changed original plugs in my 01 merc V8 at 105k showed some were tough to get out, but no damage and new ones went right in with anti seize on them. made sure engine was cold and i was careful but didnt feel comfortable. seems all of that anti seize bug juice was gone after 14 years of operation. maybe a new product with a longer life is needed to compensate for the much longer plug change interval. what think you ? thanks tons oldduke ps - are you related to mr. machine, a well known character in the early 60s?