View Full Version : Penetrating oils-comparison

04-03-2010, 10:12 PM
This is a cut and paste from another forum. It may be old news but I have not seen it before. Just passing it along as it seems to be useful info.



Here is some useful information for any of you that might end up rehabilitating a boat that sat in the water to long.

Machinist's Workshop magazine actually tested penetrants for break

out 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.

04-04-2010, 07:19 AM
Note that acetone is nasty nasty stuff, also.

I wondered about that. All those years it was (and is) used as a fingernail polish remover. I looked at the MSDS and agree that you don't want to play with the stuff but it seems on par with other stuff we use around boats, like gasoline, various thinners, and many adhesives.

Ian McColgin
04-04-2010, 07:40 AM
The thing I like about Liquid Wrench and WD-40 - I use WD-40 a bit more since I like how it remains after the job and I know it's more a water displacer than a rust buster - is that either is relatively safe when I get tired to squirting and tapping and fire up the torch.

04-04-2010, 12:38 PM
I will take acetone anytime in preference to the solvent in PVC pipe joint cement.

04-06-2010, 02:53 PM
The main hazard from acetone is its low flash point of about 0 degrees F. It is very volatile and quite flammable. But gasoline is much more hazardous - not only is it much more volatile and flammable, with a flash point of about -55 degrees F (that's 55 deg. below 0), but it also contains various organics known to have all kinds of nasty health effects, including benzene (known carcinogen).

Acetone is not "toxic" in that it has not been determined to cause cancer or other toxicological effects. But it can go *woof* if you're not careful, and if you breathe the fumes enough, you can become intoxicated. But get out into the fresh air and you will recover. Acetone also will dissolve the oils in your skin and give you a nasty rash - chemical contact dermititis. So use it in a well-ventilated area and use gloves.

I've used Kroil for years in tearing apart and restoring old woodworking machinery, and it is without a doubt the best commercial product I've found at penetrating and freeing up really stuck, rusty things. That, plus a torch.

As has been mentioned, the acetone/ATF mix likely would not be as stable to store in the long run, as the acetone will eventually evaporate away - unless you store it in a tightly sealed, metal can. Please don't use plastic, because the acetone almost certainly will soften and dissolve it, and absolutely don't use glass - for any flammable liquid.

Just say, acetone doesn't scare me - unlike some other chemicals that come in those little rectangular metal cans.

peter radclyffe
04-06-2010, 03:40 PM
thank you all

04-06-2010, 03:55 PM
good stuff to know, liquid wrench has been in my toolbox since my wrenching days, never heard of atf and acetone.