Using engine oil to prevent rust is still a common practice in many parts of the world. Knowing it as a traditional method, people often overlook its effectiveness and negative impacts.
Rust is a common problem in factories, cars, lawnmowers, snowblowers, and other metal parts, especially in places where the humidity is high.
We have compiled a guide to check if engine oil prevents rust.
Let’s Go!
Table of Contents
What is Motor Oil Made Of?
Formulated with a unique and proportional blend of base oils, viscosity modifiers, and performance additives, motor oil works as an excellent lubricant. These ingredients are added in a measured ratio to enhance engine performance.
How Does Rust Form?
Rust basically is a reaction between iron and oxygen in the presence of water. When iron contacts oxygen and water, it results in a reddish-brown flaky surface we call rust. These reddish-brown flakes are hydrated iron oxide.
When iron breaks down due to rust, we call this process corrosion. Corrosion worsens when the humidity level of air is high or when you place the metal piece underwater. To prevent rust, keep your metal substances away from water and humidity.
Disadvantages of Rust
Rust slowly eats your machinery by decreasing its lifespan. Factories spend a part of their profit either stopping machine rusting or buying new machines.
Rust weakens metal pieces, changes their physical and chemical properties, and changes their appearance completely.
Pros and Cons of Using Motor Oil to Prevent Rust
Although using motor oil was a common practice in the past, we need to see its pros and cons before applying it to prevent rust.
Engine oil is comparatively cheaper than rust inhibitors. Also, it is widely available everywhere. Instead of wasting used engine oil, people prefer to use it for other purposes such as painting wood or soaking metal parts to prevent rust.
However, engine oil comes with a lot of drawbacks we often overlook. Engine oil is a liquid that won’t stick to one place. In turn, you have to use a large amount of engine oil to paint more coats.
As it will spread throughout, engine oil creates a lot of mess. Once dried, its rust prevention ability decreases to a great level.
Furthermore, if engine oil spills on the ground while applying on things like lawnmowers, it will result in soil contamination, permanently making the soil infertile.
Apart from this, if we drain the spilled engine oil, it causes severe water pollution, harming marine life. If you choose to spray it under the car, it may not reach smaller, hard-to-reach locations.
Also, as engine oil is a thick liquid, it readily attracts dirt and other impurities, so even if it somehow helps against rust, you need to keep up with the metal part’s maintenance. A thick liquid won’t penetrate deeper into thin cracks, and rust may form there.
Engine oil may take many days to dry, especially if you live in a humid or cold place.
Should You Use Motor Oil for Rust Prevention?
If I were given the option, I wouldn’t use motor oil for rust prevention. Instead, I would prefer using rust inhibitors.
Motor oil somewhat protects car parts, but if you switch off the engine for one day or so, the engine oil will go back into the oil sump, leaving the car parts prone to rust.
Once rust develops, it will keep spreading slowly to other parts, including crankcase walls, cylinder walls, and piston rings.
Most engine oils don’t have rust inhibitors added, thus won’t protect against rust and corrosion. Hence, we recommend you not to use motor oil for rust prevention. If you still want to use motor oil, do add corrosion or rust inhibitors in it
Why Should You Use Rust Inhibitors For Rust Prevention
A rust inhibitor possesses the following properties:
- It cures rust within a few hours only.
- It will spread to the thin cracks in metal.
- Using rust inhibitors has no environmental damage.
- It won’t cause any mess.
- It doesn’t smell musty like engine oil.
Read our guide about engine oil smells.
How to Prevent Further Rust from Attacking Metal Parts
We have gathered step-by-step procedures to prevent metal parts from further rust.
- Remove the oil and dirt from the metal part using mineral spirit.
- Now brush off rust flakes using a wire brush or by sanding.
- Rinse the part with water to remove lighter rust.
- Pour the rust inhibitor into a clean container.
- Now, brush, spray, roll, or use a sponge to cover the metal surface with a rust inhibitor. You can use spray for larger bodies.
- Leave it to dry for half an hour until the inhibitor darkens a bit.
- Apply another coat for better protection.
- Leave it to dry for a day.
- When dried, apply a topcoat.
Make sure to keep tools at a dry place when you perform the method above.
Tips to Control Humidity and Keep Metal Parts Dry
You can place moisture-absorbing gel packs into toolboxes or cupboards where you have set the metal tools.
Else, use a vapor-corrosion inhibitor. It is a water-based molecular coating that protects the metal in enclosed places for many months. VCI fills enclosed space, sealing our water and protecting against rust.
How to Rust-Proof These Metals
Our households have many metal things, and we have combined a guide to rust-proof them all.
Cast Iron
Oil to be used: vegetable oil
How to rust-proof it:
Start by scrubbing cast iron with hot soapy water. Now spread a thin layer of vegetable oil over the cast iron and placed it in the preheated oven. Let it heat for one hour. Now cool it and rinse clean it.
Bare Steel
Oil to be used: light oils
How to rustproof it:
Apply a thin layer of light oil and wait for 10 minutes. Now, scrub the rusty spot with steel wool. Wipe off excess oil and clean it with warm water.
Steel and Stainless Steel
Oil to be used: linseed oil
How to rustproof it:
Put a thin coat of linseed oil on steel or stainless steel and leave it for 10 minutes. Now, scrub that rusty spot with steel wool or sandpaper. Wipe off the remaining oil.
FAQs – Does Engine Oil Prevent Rust?
Check out these frequently asked questions regarding engine oil’s use for preventing rust.
Name Other Rust-inhibitors than Engine Oil
Famous rust inhibitors include oil-based products, petroleum-based products, sandblasting, electrolysis, acids, and alkalis, plant extractors.
How to Protect My Engine from Rust?
Here are some tips to protect your engine from rust.
- Start with cleaning your engine.
- Prevent your engine from friction and wear.
- Constantly lubricate car parts to prevent heat.
- Prevent corrosion and rust.
Why does the bike lose too much oil? Read here.
How to Prevent My Car from Rusting
Rust will find its way to grow anywhere until you take the necessary precautions. Here is the best you can do:
- Don’t park your car in the water, grass, or poor drainage lands.
- Clean and rust-proof it regularly.
- Keep its fuel full.
Read more about engine oil uses and properties on our website.
Final Words
Does engine oil prevent rust? No, it doesn’t. Engine oil may work great as a lubricant, but it doesn’t prevent rust. People think that because it makes a coat between the metal surface and air, it can prevent rust.
If you still want to use engine oil for rust prevention, dilute it with rust-inhibitors. Using engine oil comes with numerous environmental damages and makes a lot of mess. As a responsible citizen, you should not use engine oil for other purposes.
Rust inhibitors are more potent and cure the metal surface within a few hours only. Use it to prevent rust.