Saw this on another site and thought that some here might be interested.
Penetrating Oils ****
> Machinist's Workshop magazine recently published some information on
> various penetrating oils that I found very interesting. Some of you might
> appreciate this. The magazine reports they tested penetrates for break out
> torque on rusted nuts. ****
>
> They are below, as forwarded by an ex-student and professional machinist.
> They arranged a subjective test of all the popular penetrates with the
> control being the torque required to remove the nut from a "scientifically
> rusted" environment. ****
>
> *Penetrating oils ........... Average torque load to loosen* ****
>
> No Oil used ...................516 pounds ****
>
> WD-40 ..................... ... 238 pounds ****
>
> PB Blaster .................... 214 pounds ****
>
> Liquid Wrench ...............127 pounds ****
>
> Kano Kroil .................... 106 pounds ****
>
> *ATF*-Acetone mix........53 pounds* **** (Automatic Transmission Fluid)
>
> The ATF-Acetone mix is a "home brew" mix of 50 - 50 automatic transmission
> fluid and acetone. Note this "home brew" released bolts better than any
> commercial product in this one particular test. ****
>
> Our local machinist group mixed up a batch and we all now use it with
> equally good results. Note also that "Liquid Wrench" is almost as good as
> "Kroil" for about 20% of the price. ****
>
> Steve from Godwin-Singer says that ATF-Acetone mix is best, but you can
> also use ATF and lacquer thinner in a 50-50 mix. ****
Ron