FAQ- Penetrating oils

DIY/TECH/INFORMATIVE
#1

I got this from a mechanical engineer friend, so I think it’s valid.

Penetrating Oils

Machinist’s Workshop Mag 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 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 almost as good as “Kroil” for about 20% of the price.

Steve from Godwin-Singer says that ATF-Acetone mix is the best and you can also use ATF- lacquer thinner 50 - 50 mix.

ATF=Automatic Transmission Fluid

#2

Wow the ATF-acetone is considerably lower than WD-40 and PB Blaster which are probably the two best known to me.

#3

Awesome information, I’m about to go mix me a batch of that up right now…

#4

Very cool. A friend of mine that works at a dealership says they all swear by AeroKroil.

#5

Interesting.

Guess I will have to go to the store tomorrow for some ATF since I have Acetone already. I have something to try out on the pinch bolts of cars now.

Did they by chance say how long the rusty bolts were soaked for? I ask because I was told to use WD-40 for stuff that had to come apart right now and then PB blaster for stuff that you had time to wait for as long as you can stand the smell.

#6

what about saliva? thats what I’ve always used

#7

What so you use to deliver the stuff? Spray bottle? Seems like it would eat the plastic.

#8

I’m a big fan of Free All. It eats away at rust quickly but the longer you can let it sit the better it works. Any idea of how long they let the products sit for the test?

#9

At work we use High Density Polyethylene (HPDE) spray bottles for Acetone.

#10

You guys have all the info on the subject that I have. I have no idea how long they soaked them. I suspect longer is better.

#11

The rankings are interesting. Before seeing this I would have sworn PB Blaster is much better than Liquid Wrench just from my own experiences.

I wonder what type of metal it was and how long the corrosion was allowed to fester…

#12

If by recently, you mean the April 2007 issue… then man recently has a different meaning to me. lol j/k because i never knew about this until right now.

Here more info
http://www.sterkel.com/papers/vintage/Testing_Penetrating_Oils.pdf

The test was the piece being immersed in the penetrating fluid for 8 hours… not exactly relevant to working on cars, as that wouldn’t quite work. Good info nonetheless

#13

It greatly depends on the metal or metals and type of corrosion. PB blaster more often then not will creep in better than others.

#14

Yea, I have found PB blaster to work pretty well for most situations that I find the need.

And if that doesn’t work, I will sometimes try a little oxy-acetylene persuasion to convince the piece it wants to move just as much as I want it to. :slight_smile:

Hammers help too. Definitely need a hammer.

#15

Thread revival.

I thought that I should bring up this old thread to say that I have been using the ATF/Acetone penetrating oil mixture on a lot of stuck suspensions lately and it works beautifully! I have found that it only takes a few minutes for the mixture to affect a stuck nut or bolt. Wish I knew about this when I was still at the dealerships fighting pinch bolts.

Thanks

#16

If it doesn’t budge with PB/WD I heat it till it glows and then it moves. The problem is once the WD/PB in on and I introduce a heat source it lights up. I end up spraying some water over the PB/WD and then hit it with the torch. I also keep a wet rag next to me and a flexible piece of heat shield that I hold with pliers in place behind the spot I’m heating up…if the space allows for it.

I really hate four things during DIY projects:
1.) Stuck/stubborn bolts/nuts
2.) Dropping XYZ in the most tight, hard to reach/access dark hole possible.
3.) Tight cramped areas only a toddler sized hand could fit and do any type of real work
4.) Forgetting something is hot as hell and adding a type of tattoo I don’t like to my skin.

#17

Glad I was able to give something back to this forum. I’ve learned a lot here.

#18

Very helpful lots of good data.