Penetrating oil is what you’re after when trying to remove certain bolts on your car that should move freely, but seem 100% stuck whatever you try. Penetrating oil is a unique type of low-viscosity fluid mixture that possesses many properties that are useful to automotive professionals and casual car owners. The penetrating fluid can help free up rusted metal parts while also serving as a general lubricant, corrosion prevention agent and an effective cleaner.
An overall useful fluid to have handy, especially if you regularly deal with older motors where bolts and nuts have become bound to vehicle parts with rust. We’ve put together our list of the 5 top penetrating fluids to buy, with a mixture of different brands and application methods for sorting out those rusty parts.
Best Penetrating Oils in the UK Reviews
#1. Plusgas English Abrasives 803-10 Tin
It’s only fitting that Plusgas’ 803-10 dismantling lubricant is the first option in our collection. This particular 500 ml tin has been favored by mechanics, locksmiths, and handymen across the UK for decades, making it the go-to option for amateur DIYers whose own nuts and bolts had seized up. The liquid in this option makes use of Plusgas’ Formula “A”, which is particularly capable when it comes displacing moisture and preventing rust in otherwise confined areas.
Despite carrying 500 ml in each tin, Plusgas’ 803-10 dismantling lubricant is fairly lightweight, thus ensuring that handymen won’t be weighed down while carrying all of their tools from job to job. Along the same lines, handymen in particular can save a lot of money by taking advantage of Plusgas’ current three pack offer. You’re certain to need some penetrating oil sooner or later, so you may as well stock up on Plusgas 803-10 now so that you can quiet machine squeaks and rattles without delay down the road.
- Formula “A” displaces moisture, prevents squeaks, and prevents rust effectively
- Favored by mechanics, locksmiths, and handymen
- Lightweight per container
- Comes in 3 packs for added value
- Direct application can be messy without experience
#2. WD-40 Penetrant
You’ve certainly heard the name “WD-40” before, likely in the context of lubricating a bike chain or a lawn mower in a pinch. Well, the makers of WD-40 know that regular consumers need penetrating liquid for more than just recreational uses, which is why they are now producing a special WD-40 Penetrant formula.
This mixture is designed to penetrate locked up metal, alloy, rubber, and plastic machine parts in mere minutes, thanks in large part to its unique inclusion of PTFE. WD-40 Penetrant can also withstand temperatures between -20° C and 90° C, allowing it to be successfully used in almost any work environment.
Applying WD-40 Penetrant is unbelievably easy too, regardless of your work environment’s unusual setup. That’s because this particular option makes use of Smart Straw technology that sprays deployed oil over a wider area without wasting a single drop. Better yet, this can includes a 360° valve that allows it to be used upside down non-stop.
- Quick acting formula bears results in minutes
- Can withstand temperatures between -20° C and 90° C
- Smart Straw allows for more precise application, decreasing waste
- 360° valve allows for upright or upside down application
- Not as easy to find and restock from local hardware stores
#3. Plusgas English Abrasives 802-10 Aerosol
As described in our #1 option, Plusgas’ Formula 'A' dismantling lubricant is without rival in the current penetrating oil market. Indeed, Plusgas’ Formula 'A' can not only dissolve rust and free up stuck machine parts, but it can also prevent new corrosion from occurring by actively eliminating moisture from the application area. But its standard form, it suffers from one considerable issue – it can be rather difficult to apply safely.
Plusgas clearly heard feedback on this issue recently, which is why their new 802-10 option comes in an aerosol can. In this form, Plusgas’ Formula 'A' provides all of its same lubrication and corrosion prevention capabilities while also dispersing over a wider application area. Plusgas even provides you as much volume – 400 ml – as its regular penetrating oil tins, thus allowing you to get just as much value out of a single affordable can.
- Trusted Formula “A” acts as a temporary lubricant and rust prevention agent
- Aerosol application provides for wider application with less waste
- Safe for use on bike and car parts
- Lacks a directed applicator
- Runs out quickly
#4. WD-40 Original Spray Can
Let’s face it – it’s hard to beat the original WD-40 when it comes to lubricating nearly every type of machinery with precision. Indeed, regular WD-40 remains the gold standard in this domain due to its proprietary blend of aliphatic hydrocarbons and mineral oil. Not only does this allow WD-40 to be used safely on everything from battery terminals and spark plugs to bike frames and door hinges, but also makes each spray can cheap (around £6 for 600 ml).
This classic WD-40 also includes one small, but crucial addition that other penetrating oil brands have sought to imitate for years. This spray can’s extended straw allows users to fire a steady stream of high quality penetrating oil into even the tightest of spaces, thus ensuring that you are able to protect metal from corrosion, moisture, and grime without wasting a single drop. This spray can also provides extra leverage during the application process, which makes a major difference when trying to apply WD-40 at a 90 degree angle.
- Cheap per unit
- Uses proprietary mixture of aliphatic hydrocarbons and mineral oil
- Can be used to safely in numerous applications, including battery terminals, spark plugs, bike frames, door hinges, power tools, and engines
- Straw allows for 90 degree applications
- Heavier than most other sprays oils, per unit
#5. 3-in-1 Professional 44014
We would be remiss if we didn’t mention another favorite penetrating oil option for UK-based handymen - 3-in-1 Professional 44014. Though it sees less use in the general population, 3-in-1 Professional 44014’s formula is actually functionally superior to most others in its class. For example, this penetration liquid can free up some rusted components in mere seconds while still managing to withstand temperatures between -30° C and 150° C.
For all of this power, one might expect 3-in-1 Professional 44014 to be extra corrosive. While this penetrating liquid is certainly caustic on bare skin (which is why you should always wear gloves when handling penetrating oil), it can be used safely on metal, plastic, or rubber without causing the surface to denature or disintegrate.
- Penetrates rapidly, with first results within seconds
- Withstands temperatures between -30° C and 150° C
- Works particularly well on chains
- Can safely be used on metal, plastic, or rubber
- May be slower to react in more secluded areas
Oil for Penetrating Buying Considerations
The Purpose of Penetrating Oil
If one of your associates has recommended that you pick up a can of penetrating oil to use on your stuck machine parts, you should first understand the purpose of penetrating oil. First and foremost, this liquid is designed to dissolve rust in narrow spaces, thus allowing stuck components to move freely again. But more importantly, it also acts as a lubricant that ensures future corrosion (caused by friction or moisture) does not immediately recur.
Penetrating oil is very volatile and caustic, though, so prospective users should only use it in a well-ventilated area while wearing proper hand, eye, and mouth protection.
Extra Volume is Always Worth It
While you’re shopping for a penetrating liquid to fit your lubrication and corrosion prevention needs, don’t be afraid to buy a higher volume than you think you need at first. Chances are, if a piece of your machinery has seized up, it will be more prone to doing the same in the immediate future. As such, value-sized penetrating oil cans or tins are always a wise choice for the prepared handyman or DIYer.
The Final Word
If there’s a nut or bolt that seems impossible to loosen, or you just want to clean a part and protect it from some nasty corrosion, penetrating oil is perfect and generally inexpensive. We’ve selected the Plusgas 803-10 Tin 500ml as our best penetrating oil pick overall, as it’s the most effective at dealing with rust and corrosion, with Plusgas being recognised by most motoring enthusiasts in the UK as a great brand. Another reliable alternative for dealing with rust and parts seizing up is good old WD-40.
Last Updated On: April 10, 2021.