This post has been around a while, you may find it interesting:
Machinist's Workshop magazine actually tested penetrants for break
> away torque on rusted nuts. Significant results! They arranged a
> subjective test of all the popular penetrants with the control being
> the torque required to remove the nut from a "scientifically rusted" >environment.
> Penetrating oil ..... Average load
>
> None ............ ......... 516 pounds
>
> WD-40 ............ ...... 238 pounds
>
> PB Blaster ............ ..214 pounds
>
> Liquid Wrench ...... 127 pounds
>
> Kano Kroil ............ 106 pounds
>
> ATF-Acetone mix... 53 pounds
>
> The ATF-Acetone mix was a "home brew" mix of 50 - 50 automatic
> transmission fluid and acetone.
>
> Note the "home brew" was better than any commercial product in this
> one particular test. A local machinist group mixed up a batch and all
> now use it with equally good results. Note also that "Liquid Wrench" is
> about as good as "Kroil" for about 20% of the price.
>
Personally I have been using ATF for years as a general lubricant. It has rust prevention, it doesn't evaporate, it doesn't turn into varnish and its cheap.
I have a 3-band Enfield I put away 20 years ago and I remember using ATF inside and out. I pulled it out last year expecting the worst. Nothing, no rust inside or out. No varnish, no crusty goo, clean.
Now I use the commercial stuff on the guns [T/C-13 is remarkable], but my little oil can of ATF gets used a lot in the shop.
I know politics, religion, and oil, can cause great debate. Matters of Faith often do.
My next topic: Vasaline[in the shop]
P.A.