Penetrating Oils

[Bear45-70]

A friend, who's hobby is restoring "old" outboards here in the Puget Sound country, AKA Salt water motors country; sent me this. These old motors have lots of steel bolts into aluminum castings. This has always been a greatly contested subject. Well, Machinist Wookshop Magazine did a little test and came to the following conclusions. I found the results to be real interesting. I will reserve comment at this time.

"Machinist's Workshop magazine actually tested penetrants for break out torque on rusted nuts. Significant results! They are below, as forwarded by an ex-student and professional machinist, Bud Baker.
*Don't forget the April 2007 "Machinist's Workshop" magazine comparison test.*
*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. Our local machinist group mixed up a batch and we 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. *
*Your experience may vary, etc., etc.



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[mousewheels]

I've seen that test, have used straight ATF before reading the article, got to try the acetone. Personally haven't noticed a large difference in Liquid Wrench vs PB Blaster, but no scientific tests have been made by me.

Wonder what materials they used in the test for bolt/nut. A lot of the stuff on scooters is stuck bolts in aluminum. What do you find works best there?

[Bear45-70]

I would think the real hard part would be in getting all the bolts and nut to corrode the same way and amount. You would need to repeat the test a minimum of 3 times and preferrably 6 times for any real accuracy.

[Lunytune]

Bear, I know you are a gun-nut. Have you ever heard of Ed's Red? It's a substitute homemade recipe for knockerloose and cleaning, and quite economical. Here's the formula: One part each of
ATF
Acetone
Mineral Spirits
Kerosene, available at Walmart in the form of lantern oil.

I've tried it on a couple of scooter projects and it works pretty good. ATF by itself is too thick. The Acetone and Mineral spirits thins it out so it will go deeper.

[noiseguy]

Good info! Steel to Al galling is bad stuff. Around Detroit, with all the moisture and salt, I did a lot of re-drilling and tapping. Not so much around AR, where it's really dry. I've never been impressed with WD40 as a penetrant, but as the article notes it's a lot better than nothing (better than I would have expected.)

I'm going to try that ATF - acetone mix the next time I get a stuck bolt. If nothing else it's almost free; I've got both in my garage right now just sitting.

[carp]

Bear,I read that test in the mag. Couldn't remember where I read it.The one thing they said about that test, was they had the luxury of soaking the parts over night. They weren't sure if the results would be the same if you had to bust the bolts right away. I've gotten in the habit of soaking over night (with the AFT/acetone mix) the bolts/nuts on the parts I'll be working on.Carp