Originally Posted by Fstbttms
The April/May 2007 edition of Machinist's Workshop did a test of penetrating oils where they measured the force required to loosen rusty test devices. Buy the issue if you want to see how they did the test. The results reported were interesting. The lower the number of pounds the better. Mighty interesting results for simple acetone and tranny fluid!
Penetrating oil . Average load .. Price per fluid ounce
None .................. 516 pounds .
WD-40 .............. 238 pounds ... $0.25
PB Blaster ......... 214 pounds .. $0.35
Liquid Wrench ... 127 pounds .. $0.21
Kano Kroil ........ 106 pounds .. $0.75
ATF-Acetone mix.. 53 pounds .. $0.10
The ATF-Acetone mix was a 50/50 mix (1 to 1 ratio).
Please be advised that acetone will attack many plastics to destruction. You don't want acetone in contact with polyester bonded fibreglass or you may find that your plastic boat is now feeling more like putty or rubber where the acetone touched it.
I know that several other penetrating oils will also attack plastic as I once saw a fellow try to borrow a "cup" of Kroil. His styrene foam cup dissolved before he could get it three steps away.
The very properties which make penetrants work through layers of old paint and accumulated congealed grease make them vicious when contacting many plastics.
I would not let any of these products touch any important rubber, paint, wood or plastic as most of them will be damaged sooner or later by the exposure.
p.s. Click the link for Main Sail's $800 PB Blaster tale of woe! PB Blaster/Penetrating Oil WARNING !!