Mod Filter


for all your modding needs, recommended by Evilution

Penetrating Fluid

Mod Description
There are loads of penetrating fluids on the market but why not make your own?
Mod Details
PremiumNo Difficulty Mod ID957 CreditInternet For450 Fortwo451 Fortwo452 Roadster454 Forfour Link Copy to Clipboard

Penetrating Fluid

Also known as dismantling fluid, penetrating oil, dismantling lubricant etc. Essentially, it’s a can of spray that you spray directly onto a seized fixing to aid in removal. The fluid seeps into the part through the corrosion that has seized it in the first place. You leave the fluid in place, ideally over night, and it should help make removal a lot easier.

How Does It Work?

More often than not, the corrosion between 2 metals has created a strong bond, either by corroding or adding oxidisation.  The “rust” is deep inside the part and therefore covers a massive surface area, making it very strong.

Oxidation is usually dry, so applying a penetrating oil will naturally wick inside the part. The oil breaks down the bond and lubricates the pieces.

Rust has a high water content. The penetrating fluid contains an alcohol base which is thinner than water and therefore it easily pushes out the water in the rust. Alcohol naturally evaporates very quickly which leaves gaps where the water was. These gaps are then filled with the oil that was suspended in the alcohol. So, the rust is dried and lubricated to allow movement between the seized parts.

Popular Penetrating Fluids

PlusGas (UK)

GT85 (UK)

TryThis (UK)

Penetrene (AUS)


Liquid Wrench (US)

Kano Kroil (US)

PB Blaster PB16 (US)

There are many many more and the choice will differ depending on your country.

Making Your Own Penetrating Fluid

Let’s look at the facts. Penetrating fluid is little more than alcohol and an oil. We can replicate that.


Don’t break out your finest Vodka, we need a higher alcohol content. Popular sources for high content alcohol are surgical spirit (rubbing alcohol), acetone (nail varnish remover), isopropanol and methylated spirits. The easiest to get hold of is nail varnish remover, if you get that, double check the label to ensure it’s acetone as some brands are replacing it with other things.


All oils will lubricate so you really aren’t limited all that much to what you use. However, use new oil. You can use power steering fluid, automatic transmission fluid, engine oil, vegetable oil, even your finest extra virgin olive oil. Just use what you have laying about. The thinner the oil the better. That’s why I recommend ATF transmission fluid over other oils.

Mixing Ratio

There are plenty of people claiming to know the best ratio however, it totally depends on what you are trying to unseize. More alcohol will displace more water. More alcohol will make the mixture thinner allowing better creep properties. Too much alcohol won’t deposit enough oil inside the seized part to be effective.

For everyday use, 8 parts oil to 2 parts alcohol (volume) will be sufficient.
For more heavy duty use you can go as high as 1 part alcohol to 1 part oil (50:50).

Personally, I just have 50:50 just because it’s better.


There are many non scientific studies that suggest that home made fluid can out perform the store bought (expensive) penetrating fluids. Having tried both ratios, I was impressed. It is important to shake the mixture before use to disperse the 2 fluids properly. Also, if you use ATF (automatic transmission fluid) as the base oil, the resulting mixture is red and therefore looks awesome.


Acetone can melt plastic and it’s incredibly flammable so be careful what you put it in and where you store it. The can that you use shouldn’t have any plastic parts which could dissolve and it should be air tight. If it’s not air tight, eventually your alcohol base will just disappear.


Having used PlusGas for the majority of my work, I am impressed by how well the home made fluid works. If you have spare oil and your lady friend has acetone nail varnish, you don’t have to spend money. Let me know how you get on and what you use.