Can Waste Engine Oil Remove Rust?
4 Answers
No. The main functions of engine oil are lubrication, cleaning, cooling, and sealing. Special rust removers should be used for rust removal. Below are the methods for rust removal: Manual Rust Removal: Use tools such as scrapers, hammers, steel brushes, sandpaper, and grinders to knock, scrape, grind, or remove rust. The advantages are simplicity and low cost. Mechanical Rust Removal: Use common tools like handheld electric grinders, electric brushes, pneumatic brushes, and rust removal guns to remove rust. The principle is to effectively eliminate rust and contaminants through impact and friction. Chemical Treatment: Use acid solutions to chemically react with rust and contaminants on the metal surface, dissolving them in the acid. Additionally, the hydrogen gas produced by the reaction between the acid and the metal can mechanically dislodge the oxide scale.
When I was young and working on old cars, I also thought about using waste oil to remove rust, but it really doesn't work. It can only provide temporary lubrication or prevent new rust from forming, not remove existing rust layers. This is because waste oil contains impurities, metal shavings, and contaminants. Applying it forms a greasy film on the surface, leaving the rust untouched underneath. What's worse, waste oil is toxic—skin contact can cause health issues, and improper disposal pollutes the environment. My advice? Don't bother with it. It's better to spend a little money on proper rust-removal sprays or chemicals, which are quick, safe, and hassle-free. For rust prevention, you can apply some rust-proof oil, but always dispose of waste oil at a recycling center—don't risk bigger problems to save small costs.
As a car enthusiast who often tinkers with vehicles at home, I've tried using waste engine oil for rust removal, but the results weren't great. Its primary function is lubrication—applying it to rusty bolts can help loosen them slightly, but the rust itself remains. The reason is that waste engine oil is thick and dirty, accumulating on the rust and easily attracting dust, making parts harder to clean. Later, I switched to rust removal sandpaper and industrial rust removers, which cleaned everything up in just a few minutes. If you still want to try waste engine oil, be careful not to drip it on your skin or the ground, as it contains chemical residues that could cause trouble. The key point is that leaving rust untreated accelerates component wear, so it's better to use professional methods early to protect your car's lifespan.
Having worked in auto repair shops for years, I've never seen used motor oil effectively remove rust. Once used, it deteriorates and lacks active ingredients to break down oxidation layers—it can even clog delicate parts. Proper rust removal relies on specialized acid cleaners or mechanical abrasion, which are straightforward and efficient. Used oil contains heavy metals, posing risks if misused, making proper recycling the better option.
