Penetrating oils - any proper scientific studies out there?

As a casual user of penetrating oils, I sometimes see comparisons of different penetrating oils on forums, where the merits of each brand are discussed, but eventually no 'leader' truly emerges.

Kroil, PB or WD40 , or even the ATF/acetone mix are always in there somewhere, but can anyone tell me if a proper scientific study is out there?

Some half assed tests online, seem to show just 1 rusty nut and bolt tested for each brand.

Now, with the many variables in individual fasteners, and especially if artificially rusted, I would think it would be prudent to have 100 rusted bolts tested with PB, 100 tested with kroil , and so on.

has any testing agency actually scientifically tested penetrating oils?

Surely, the military must've gone down this route at one time?

I think it would be difficult to do any sort of scientific study since the first part of the problem would be to come up with a bunch of identically rusted fasteners. The only things one could do rigorously would be to measure capillary flow and lubricity. In my experience on a variety of rusted fasteners any of the "big three" (Kroil, PBlaster, or Liquid Wrench) work well. With Kroil being perhaps being the best, PBlaster being second, and Liquid Wrench being last. In my opinion the ATF/acetone mix works okay if the parts don't need long soaking (like hours to days). The acetone evaporates too quickly.

I would never consider WD-40 to be a penetrating oil. That is not what it was made for.

What does stoddard solvent and a small amount of varnish (WD-40) have in common with penatrating oils?

I suppose it's good for cleaning up after ;-)

I like Dexron for just about everything along the lines of general lubricant. It also is a great penetrator.

Also, most questions regarding ANY oil related subject have probably been answered here.
Bob Is The Oil Guy | The Internet's Number One Motor Oil Site

From my experience as a mechanic, each does a different job exceptionally well and passably well in others. Kroil is best for severely rusted parts, wd40 for short term lubrication and rust prevention (air tool lube also), pb for moderate rust and galled fasteners(very good with stainless), justice bros 80 for short term severe wear prevention and moderately long term lubrication (very good with cables/wire rope).
They all work better than nothing.
Atf has a friction modifier, good rust prevention but not a very good lube option. 10w Motor oil will do the same or better.

thermite said:

...corrodicles...
Bill

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I will be using this word.

thermite said:

.. and back in the day when one could buy just about any chemical or solvents, another trick was to tip-in a ration of synthetic oil of wintergreen and/or Xylol to improve penetration.

One old Master swore by sticks of beef tallow - applied hot - for loosening corroded exhaust manifold bolts .. on the First World War Mercedes aero engines he had built and serviced, anyway.

All else fails, either a ox-acetylene torch or fuming nitric acid gets the job done. But oye, the hazards!



The closest thing I have found to a 'one size fits all' is not a liquid anyway.

Rather, the patient, careful, AND NOT ham-handed application of LIGHT, rapid impacts from an air wrench or ratchet. Apply the fluids of choice, perhaps few mild, not destructive heat/cold cycles. Go do something else.

Repeat later.

When you've 'bout given up hope, the sucker finally cooperates.

More often than not, the vibration breaks down the corrosion built up and lets penetrant get in to do whatever it can do. Works a treat where a steady pull would simply hard-wedge the corrodicles and snap the fastener.

YMMV, but a comprehensive set of SAE and metric thread restoral files, taps, dies, EZ-outs and similar extractor tools will cost less over a fifty year period than even just a few years worth of the spend on liquids.


Bill

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One of the best is DMSO and 10w motor oil, it penitrates everything, gloves and skin included. I'm also very allergic to DMSO so that one is out...

But your right about using a proper technique. A good one is to try tightening just a little (ie enough to know the fastener moved) then loosen. But they all carry the risk of breaking the fastener and take time. Get in a hurry and its going to break, especially if its a rush job at 4am on a Sunday....

thermite said:

The closest thing I have found to a 'one size fits all' is not a liquid anyway.

Rather, the patient, careful, AND NOT ham-handed application of LIGHT, rapid impacts from an air wrench or ratchet. Apply the fluids of choice, perhaps few mild, not destructive heat/cold cycles. Go do something else.

Repeat later.

When you've 'bout given up hope, the sucker finally cooperates.

More often than not, the vibration breaks down the corrosion built up and lets penetrant get in to do whatever it can do. Works a treat where a steady pull would simply hard-wedge the corrodicles and snap the fastener. Bill

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I have used the above on many different fasteners, and a wood lathe with drive and tail centers rusted in Morse tapers, hand wheel and face plate rusted on spindle threads.

I got the lathe way below market price and spent a weekend squirting PB, heating, and tap, tap, tapping with a small brass hammer. Everything came apart with no damage.

Paul

bic said:

can anyone tell me if a proper scientific study is out there?

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This comes up from time to time and, as you can see from other posts, everyone has an opinion on what to use. However, to answer your question, I've searched fairly thoroughly myself but have not found anything like a scientific study. I wish there were, so if anyone does find one by all means post it. The "study" often cited that was published ten or so years ago in the amateur machinist magazine doesn't even count as a worthwhile attempt.

In May of 2009, there was a similar discussion on one of the boating forums that I sometimes visit. After a very long iiscussion, someeone posted this.

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. *

The "Home brew" stuff has worked well for me several times.

A few years ago at Cabin Fever I passed up a chance to buy a can of Farty Artie's Nut Buster - "Let Artie Bust Your Nuts for You" - and I've always regretted it. I don't know if it would work better than any other, but I sure thought it would stand out on my shelf. And maybe keep the other commercial products on their toes.

DMSO?

George

Pure bullshit

If the bolted assembly could stand 500 foot pounds than the 50 was an improperly tightened test subject.

Lost Again said:

In May of 2009, there was a similar discussion on one of the boating forums that I sometimes visit. After a very long iiscussion, someeone posted this.

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. *

The "Home brew" stuff has worked well for me several times.

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Heavey Metal said:

Pure bullshit

If the bolted assembly could stand 500 foot pounds than the 50 was an improperly tightened test subject.

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It was supposedly "rusted", so I suppose that would qualify as "improperly tightened".... Otherwise not.

I think all the tests are BS anyhow. ESPECIALLY THAT ONE IN PARTICULAR.

1) To do even a halfway job, you'd need to have maybe 100 pieces of each test item. In that many, the "average" would have some meaning. With 1 or 3 or 10 pieces, no meaning whatsoever. And the standard deviation would be needed , as well as the range, to make any determination of worth.

2) Application technique is important... if the penetrating oil is going to work, there must be small spaces in there, full of air, or something....I see folks douse both sides of the thing... and how do they expect the air that is in the small spaces to get out and let in the oil? Put it on one side, and let it penetrate through.

3) Acetone and ATF mixture? Some versions do not mix, others do kinda. Which type/brand of ATF do these people mean?

4) Rusting.... Everything that I ever need to remove has been rusting for years... not the short time prior to a test... What relation can a short time rusting possibly have to a long term rusting situation? Correct... almost no relation at all.

In any case, the dosing and tapping and waiting technique just does NOT work..... not when you need to fix something now. You don't have a week to wait.

If you can destroy the rusted parts, it's lots easier. if you can't, not so much...

The combination of heating and THEN putting on the oil mix can be helpful..... the heat can help draw in the oil, assuming you can't heat that hot for some reason.

Some things don't come apart.... or if they do, they are no longer useful... the threads are rusted off, etc.

Georgineer said:

DMSO? George

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Dimethyl Sulfoxide otherwise known as horse liniment. As the poster mentioned will penetrate skin and carry along with it whatever it is mixed with. Want to get motor oil in your bloodstream?

"Acetone and ATF mixture? Some versions do not mix, others do kinda. Which type/brand of ATF do these people mean?"

what atf did you find not to mix? was it acetone or something else you used? i have yet to find an oily substance, that acetone (or nitro thinner) doesnt dissolve. the nice thing about it, is that you can adjust the mixture. whats the problem with acetone evaporating? just add some more into the joint after a while.

Should be easy to create a bucnch of nuts rusted on bolts some what evenly (think salt water, a cement mixer and a fortnight holiday). Say a couple of hundred then do lots of 10 or 20 with each penetrant. Should soon become apparent results wise if any really are better.

As to acetone + ATF. Is that pure acetone or the cheaper crap full of methanol, water and other junk?

Interestingly, the test pretty much parallels the placebo effect I've experienced for decades, but for the exclusion of Gibbs in the test and my not yet trying any acetone/ATF mix.

btw: IIRC, the best 'Pure bullshit' for rusted parts is organic and harvested from (behind) free-range bovines. (Heating cycles are totally up to the user.)

Adama, folks here Stateside have been telling me for years that our petrol is being watered down, too. Makes sense to me if they're willing to pay more/gal for bottled well water than for fuel.

dian said:

"Acetone and ATF mixture? Some versions do not mix, others do kinda. Which type/brand of ATF do these people mean?"

what atf did you find not to mix? was it acetone or something else you used? i have yet to find an oily substance, that acetone (or nitro thinner) doesnt dissolve. the nice thing about it, is that you can adjust the mixture. whats the problem with acetone evaporating? just add some more into the joint after a while.

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I have a Chevron brand synthetic ATF that WILL NOT mix with acetone. I can shake it up, and an hour later the oil is on the bottom and the acetone on the top. Leave the jar open and a day later the acetone is gone. ISO 22 dinosaur mix hydraulic oil and acetone does mix.