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What is the formula for homemade penetrating oil?

Posted: Mon Feb 04, 2019 3:07 pm
by WayneJ
I recall a previous thread about a homemade formula for penetrating oil containing automatic transmission fluid and at least one other ingredient. What is the formula? Thanks!

Re: What is the formula for homemade penetrating oil?

Posted: Mon Feb 04, 2019 3:11 pm
by John.Zibell
50% ATF, 50% Acetone.

Re: What is the formula for homemade penetrating oil?

Posted: Mon Feb 04, 2019 6:06 pm
by Tiger Tim
john.zibell wrote:
Mon Feb 04, 2019 3:11 pm
50% ATF, 50% Acetone.
For what it’s worth the test that determined how awesome that formula is was questionable at best. If you have to go out and buy either acetone or ATF just buy penetrating oil.

Re: What is the formula for homemade penetrating oil?

Posted: Mon Feb 04, 2019 6:33 pm
by Mark Gregush
My and a few others OP; The only good thing penetrating oil is good for is emptying your pocket and lubing the exposed threads, a good lite oil will work as well. Paraffin and heat works better in many cases. Heat allows the metal to expand and as it cools breaks the bond allowing the paraffin to soak down into the threads. Penetrating oil would/can take forever to even get where it needs to go.

Re: What is the formula for homemade penetrating oil?

Posted: Mon Feb 04, 2019 7:44 pm
by Bill Robinson
Don't knock John's recipe until you've tried it! :roll: That stuff works!

Re: What is the formula for homemade penetrating oil?

Posted: Mon Feb 04, 2019 8:07 pm
by 2slow

Re: What is the formula for homemade penetrating oil?

Posted: Mon Feb 04, 2019 9:25 pm
by Raoul von S.
The 50/50 mix of ATF and acetone is well known as a good P-oil, but acetone evaporates
super fast, leaving just the ATF. If penetration is not happening, try a heavier solvent, such
as lacquer thinner or mineral spirits.

I am currently battling an age-locked 2.5" zinc nut on a bronze toilet tank hub. I cannot
risk breaking the porcelain, so heat is not an option, forcing me to rely entirely on P-oil.
The acetone was gone so fast, all I was left with was ATF, so I stepped it up to lacquer thinner.
My very special home-made wrench has had the handle extended to 24" and I still can't get
it to break free. This cold weather is not helping.

Patience, Grasshopper ..... 🦗

Re: What is the formula for homemade penetrating oil?

Posted: Mon Feb 04, 2019 9:43 pm
by Steve Jelf
If you're using 50/50 keep it in a sealed container to prevent evaporation. It will separate, so shake it up before using it. I use a squirt bottle with a little cap to keep it sealed. I agree that a penetrant may not be the answer. Sometimes you have to use the heat wrench, turning the stuck parts red and letting them cool.
IMG_2336 copy.JPG

Re: What is the formula for homemade penetrating oil?

Posted: Mon Feb 04, 2019 10:37 pm
by John.Zibell
Good study. Heat best followed by liquid wrench and then home made acetone and atf.. The expensive Kroil, not so good. Thanks for posting the study.

Re: What is the formula for homemade penetrating oil?

Posted: Mon Feb 04, 2019 10:42 pm
by Aarongriffey
When I rebuilt the engine and transmission and brakes on an early fifties car I used a lot of aceatone and ATF. Mix.
The owner is a garbage truck driver.
He said the mechanics listened to him tell about the home made p oil and tried it themselves.
He says there is a problem that happens to their trucks that requires removal of a bracket bolted to the engine block.
He says they ALWAYS breach the bolts off that hold that bracket on.
So they tried the ATF acecetone mix and ........you guessed it... no more broken bolts.
You need to keep the stuff in a clear glass or plastic container so that when you pick it up you will notice that the mixture has separated and you must shack the container to mix it well before using.
You can also add MEK to the mix. Methyl ethyl keyatone.
Oh it is not only better than any penetrating oil you can buy but it is about one tenth the cost.

Re: What is the formula for homemade penetrating oil?

Posted: Tue Feb 05, 2019 12:41 am
by Duey_C
I like using a scissor-shortened solder brush to apply 50/50 ATF/thinner (from an old cat treat cup) to a HOT part or waiting until the ATF boils on said part after heating it.
It does help! But it only gets SO far as stated! The store bought stuff works slightly less but works. IMHO.
I use cheap V,M&P? naptha thinner that doesn't evaporate so quickly and doesn't separate. SOME others sure do separate.
MEK (Methyl Ethyl Ketone) would be good too, (I suppose the HOTTER/MORE VOLATILE the thinner, the smaller the molecule-to help get the ATF in there) but it's naughty to us and we really shouldn't mess with it in our home shops unless well ventilated. Please. Nervous system (our wiring) problems later on.
Walking out of work with rubber knees 20 years ago, for a year or more because of the chemicals?
Don't breath it if you can help it. Never let the hotter thinners on your skin. NEVER.
Shoot. MEK is the least of our worries, (really Duane? you typed that? Dip.) iso and di-isocyanates are a bigger problem in some Poly paints. BTDT. Yuck.
Oops. Sorry. Ol' rubber knees shuts up here. And you fellas wonder about me...... :lol:

Re: What is the formula for homemade penetrating oil?

Posted: Tue Feb 05, 2019 7:41 am
by ROBERTHOOPS
Some years ago, we hired a plumber to replace the shower head in our 65 year old house. He worked for a long time trying to get everything loose. Finally, he said he would need to break out the tile in order to get it out. He was using some kind of spray solvent. I asked him to wait while I mixed up some ATF and acetone. We soaked the area for about 3 minutes and the fittings/pipes came loose.

Re: What is the formula for homemade penetrating oil?

Posted: Tue Feb 05, 2019 8:03 am
by RustyFords
I've tried the 50/50 homemade mix and the store bought stuff, and I do think the mix is slightly better. Neither ever seem to truly penetrate down into the threads of a stuck item though. Here's my time-tested method for removing stuck fasteners:

- Apply some heat (if possible)
- Tap it as forcefully as possible without causing damage
- Apply penetrating fluid liberally
- Rock the fastener back and forth. Sometimes it's imperceptably small movement at first. I alternate between tightening and loosening and the purpose is to get that penetrating fluid to start working its way down into the threads. If it's a real bugger, I may have to rock it back and forth while adding even more penetrant. If it's going to come loose, the amount of movement in either direction slowly starts to increase.

I like returning old fasteners to the cars on which they lived their lives. Something about it just feels right to me and I've saved many a fastener using this sequence that others have given up on.

Re: What is the formula for homemade penetrating oil?

Posted: Tue Feb 05, 2019 8:35 am
by perry kete
Wow! and all this time I've been mixing it wrong...
I thought the mix was 50% Acetone and 50% ATF but now I find out it's 50% ATF and 50% Acetone! I'll have to revise my formula. :roll:

Re: What is the formula for homemade penetrating oil?

Posted: Tue Feb 05, 2019 8:54 am
by HornsRus
fire and water has never let me down!!!!! charley

Re: What is the formula for homemade penetrating oil?

Posted: Thu Feb 14, 2019 6:53 pm
by Tmodelt
Don't forget folks that acetone IS a known carcinogen that will penetrate your skin (pores). I am in trouble later in life due to using this stuff to clean my hands in a past job setting. Used to have it readily available in 55 gal drums.

Re: What is the formula for homemade penetrating oil?

Posted: Thu Feb 14, 2019 7:02 pm
by BobD
Whoa! I don’t see anything on my can of acetone or the MSDS indicating it is a carcinogen.
In any event, penetration of the skin is not a good thing, especially if one uses it to remove other substances on the hands.

MSDS
http://sds.chemtel.net/webclients/safar ... cetone.pdf

Re: What is the formula for homemade penetrating oil?

Posted: Thu Feb 14, 2019 8:29 pm
by DickC
I was going to add "wiggle" but Rustyfords beat me. I always try to wiggle/loosen the nut/bolt a little at a time by turning both ways. Lets the oil penetrate into the threads.

Re: What is the formula for homemade penetrating oil?

Posted: Thu Feb 14, 2019 9:07 pm
by Dan B
KROIL

Re: What is the formula for homemade penetrating oil?

Posted: Fri Feb 15, 2019 12:06 am
by Steve Jelf
Kroil is probably the best brand commercially available, but it's less effective and much more expensive than 50/50.

Re: What is the formula for homemade penetrating oil?

Posted: Fri Feb 15, 2019 7:01 am
by Herb Iffrig
I came across this stuff :
free all.jpg
Wow!
It really works.
My buddy Jim swears by it now.

Re: What is the formula for homemade penetrating oil?

Posted: Fri Feb 15, 2019 9:01 am
by Ruxstel24
I swear by this stuff. Originally called "heat valve lube"....fondly called "panther pi$$" !!
Of course heat/quench, sometimes just heat.

Re: What is the formula for homemade penetrating oil?

Posted: Fri Feb 15, 2019 10:57 am
by Les Burg
The original Formula was 50/50 ATF and trichloroethelyne, whith is now outlawed.
This all came from the Home Shop Machinist magazine around 2011, here is the tread from the HSM form.
If you want to read the tread here it is, respone #34 from the editor George Bulliss tells the story http://bbs.homeshopmachinist.net/thread ... -Oil/page4
I hope this helps.
Les

Re: What is the formula for homemade penetrating oil?

Posted: Fri Feb 15, 2019 1:36 pm
by George N Lake Ozark
The only draw back from the 50/50 mix is that it does melt plastic. So be careful of the container you hold it in.

Re: What is the formula for homemade penetrating oil?

Posted: Fri Feb 15, 2019 4:03 pm
by Cliffy
I've used something different than ya'all.
Aviation industry has what they call "Dye Penetrant" systems for locating cracks in metal parts. The "penetrant" spray (usually red in color) sucks into the smallest microscopic cracks.
It really works good as a PO. Stains everything good also :-)

Re: What is the formula for homemade penetrating oil?

Posted: Fri Feb 15, 2019 5:19 pm
by Tmodelt
Acetone formula may have changed. I quit using it 35 years ago after I stopped building fiberglass bodies and molds.