As far as I am concerned, Aero Kroil is THE penetrating oil - the shop that maintains our club C-172 (and big Beechs, Aero Commanders and so on) buys it by the gallon. They offer a trial deal on a can or a few cans (it is available in spray can) - SiliKroil is also super stuff - a somewhat new addition to Kroil which is decades old (SiliKroil also is good for a tap / die lube, as well as penetrating oil).
http://www.kanolabs.com/ Jim Beach Brennan WST
