Make a Better Penetrating Oil





Introduction: Make a Better Penetrating Oil

We found a low-cost, do-it-yourself competitor with WD-40 lubricating spray: Vegetable oil and acetone.

A team at Drexel University in Philly conducted side-by-side comparison tests of vegetable oil mixtures, WD-40 and automatic transmission fluid, and found that a mixture of vegetable oil with 10 percent acetone works as well to free rusted bolts as WD-40. And it costs about one-tenth of the price. Add more acetone, up to 30 percent, and the mixture works even better than WD-40 and still costs about one quarter the price.

Acetone, by the way is the active ingredient in nail polish remover and some paint thinners, and DIY mixtures with transmission fluid are sometimes used as a penetrating oil.

[Images by (left to right)  cottonseedoil, dchou0123 and ATWJ - / Flickr]

Step 1: Tested & Approved

The Drexel team placed 3/4” and 1-1/8” nuts and bolts in salt and sulfuric acid solutions for one week to rust. Then they applied penetrating oil mixtures and tested the bolts with a torque wrench.

Vegetable oil with five percent acetone works. Increasing the acetone to 10 percent or up to 30 percent boosts performance. At higher concentrations, you can free the seized bolt using less than half of the force that it takes with WD-40.

The bottom line is that vegetable oil with 10 percent acetone is more effective at freeing seized bolts than WD-40, it's as effective as ATF and acetone, and it is more widely available in rural developing areas and kinder to the planet both in manufacture and disposal.

This might be useful in anyone's garage, but we're hoping that it's especially helpful in rural developing areas where commercial lubricating sprays can be expensive and vegetable oils are easy to find and even possible to make.

The tables show a cost analysis and a comparison of the force needed to remove a seized bolt (courtesy of the Drexel team).

Step 2: Details

For details, see E4C's report: How to make penetrating oil
And Drexel's test results (pdf)



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Please be positive and constructive.




I noticed the cost per liter for the products used.

The ATF and WD40 must actually be cost per gallon at that time. Still pretty close in 2017

It was a secret for a long time but the lubricant in WD-40 is actually fish oil.

That is a myth.

Not and never was fish oil.

not lubricant *** WATER DISPLACEMENT**** 40th attempt hence WD40 !!
However i love your instrucable and will try itout Thank you.

WD-40 was originally developed as a conservative agent to store missiles. Or so I've heard. They made it to stop rust, not fix the stuff. If what you have is already rusty it is too late for WD-40 to do you much good.

Not my instructable. And I stand corrected.

Hi - this is a great instructable.

I was wondering if you might find an offshoot of interest.

I paddleboard/longboard and there is a lot of hype about using special lube oils or creams to ensure smooth running of the wheels (don't get me wrong they work amazingly well), but they do cost a lot for just a little - it would be great to find a cheaper home version and your team has done a great test here so any results you might have found would be mega trustworthy.

Your now on my fave follow list and look forward to all your new posts.

Engineering for change. Someone below who did the study said the CHART IS WRONG.


"yeah this may be a data error. I didn't craft the chart above. On my final report however it does in fact show a decrease in required torque for the rusted bolt with the increase in acetone. I'll see if I can find the report and post that chart for a correction. "

Awesome instructable. Great work!

I try to make homemade wd-40 one time, but i use mineral oil and benzine (A.K.A petroleum eter or white spirit ), as in the original formula.
I use much less oil than you, 20% oil and 80% benzine, it work as well as the wd-40, but the fact of not having a properly way to store it, the benzine dry and only left the oil behind.
The wd-40 also have a light grease and deoxidants.

Cool instructable by the way.