This is going around the interweb in a lot of DIY machine and auto forums so I thought I would pass it on here. We seem to crack a lot of nuts and bolts here too.The best results were surprising to me at least.
"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. the test device's were clinically rusted for similar results. many bolts were used then averaged for the torque numbers. 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)."
"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. the test device's were clinically rusted for similar results. many bolts were used then averaged for the torque numbers. 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)."
) on my exhaust replacement project for my 1991 Toyota pickup. 21 year old truck, original exhaust, studs/nuts holding the downpipe on completely encrusted in rust. They are a PITA to get to so I was very nervous about breaking them. The week prior to replacing the exhaust I gave the flange a spritz of PB Blaster three different times over the course of five days. When I finally removed the studs they came out with minimal effort and they broke loose rather smoothly rather than with a sudden "crack." I'm convinced that the method of application is just as important as the type of penetrating oil itself. Now if I can only remember to do it...