Various spray lubricants and penetrating oils come in dozens of different types at your local hardware store or home center, and while all of them have their uses, it's worth noting that a great many of them are envious attempts to copy the success of one particular petroleum-based spray product that is sold in a blue-and-yellow can—a product that most of us have in our workshops or garages.
That product is, of course, WD-40, a favorite of garage mechanics and DIYers since the late 1950s. WD-40 is a thin, petroleum-based liquid, usually applied via a aerosol can, specifically designed to dissolve and remove rust, and to prevent rust and corrosion by protecting metal with a thin coat of fine oil. It is not designed as a lubricating oil, though there may be instances where its ability to penetrate can be helpful in freeing up parts that are stuck due to corrosion. As nearly every homeowner comes to learn, though, WD-40 has a remarkable list of additional uses around the house.
The History of WD-40
WD-40 began its peculiar journey in a small research lab in San Diego in 1953, when Rocket Chemical Company and a small staff attempted to develop a line of solvents to prevent rust in rocket parts. Such capabilities hinge on a solvent's ability to displace water, and it was on the fortieth attempt that the research team got it right. The name WD-40, standing for "water-displacement, 40th attempt" was taken right from the notebooks of the research team. This marks one of the few moments when a product name did not receive a Madison Avenue makeover from a publicity team.
The product was so useful that workers often stole cans to bring home, and thus by 1958, the company decided to package the product into aerosol cans for sale on the broad consumer market. Now approaching 70 years in operation, the WD-40 company has never been taken over by another huge conglomerate, though it did go public with a stock offering in 1973. Over the years, it has purchased other companies, including the companies making 3-in-1 oil, Lava soap, and Shot-Spot carpet cleaners. But its signature product, WD-40 in a spray can, remains its bestsellers. It's estimated that four out of five U.S. homes own at least one can of good, old-fashioned WD-40.
What Is WD-40?
The exact ingredients in WD-40 are a trade secret, but analysis shows that it consists mostly of a variety of petroleum-based hydrocarbons. About 45 to 50 percent is simple kerosine, slightly less than 35 percent is a petroleum oil, and the rest is a mixture of other petroleum hydrocarbons comprising the "secret." Each can also contains 2 to 3 percent carbon dioxide as the spray propellant. Surprisingly, the formula was never patented, and plenty of competitors have attempted to duplicate the formula, though none to the same degree of success enjoyed by the WD-40 company.
WD-40 was formulated to dissolve and remove rust, and to displace water to prevent future rust and corrosion. While there are many other "off-label" uses for this oil, only some of them have been recognized by the WD-40 company. When using WD-40 in a manner not recommended by the company, use caution to make sure the product does not damage other materials. And remember that this is a toxic, flammable material that should not be used by children.
Common Uses for WD-40
The official "on-label" use for WD-40 is for various applications as a rust-preventer and degreasing solvent. It is not formulated as a lubricating oil, and there are other products that are better suited for that job (such as 3-in-1 oil). But for mechanics and DIY homeowners trying to loosen screws, bolts, and other parts corroded or rusted together, WD-40 is the product first off the shelf. Rusted tools can be quickly cleaned and protected by scrubbing them with WD-40.
But if this was the limit of WD-40s usefulness, it would not have reached the enormous household popularity it enjoys. Among the many off-label uses, here are some acknowledged by the WD-40 company itself:
- Removing road tar: The thin kerosine-like component in WD-40 is very good at dissolving thicker petroleum substances, such as the gummy road tar that can stain the painted metal on your car.
- Removing bumper stickers: The gummy adhesives that hold bumper stickers to your car are easily dissolved by WD-40.
- Removing crayon from walls: Kid's crayon marks are notoriously difficult to remove, but WD-40 does the job with ease. You will, though, then need to wash the walls with a grease-removing detergent to remove the WD-40 residue.
- Removing rubber scuff marks: Most modern rubber is actually a petroleum byproduct rather than a natural rubber derived from tree latex sap, and WD-40 is great at dissolving this substance.
- Cleaning stainless steel: Oily fingerprints, cooking greases, and other substances are easily removed with a spray of WD-40 followed by a thorough wiping with paper towels.
- Lubricating squeaky hinges: Although not technically a lubricating oil, WD-40's thin oils are great at penetrating the crevices between the parts on door hinges. Just a very little amount does the trick; make sure to wipe away all excess.
- Removing duct tape: Duct tape has a notoriously sticky adhesive that gives the tape is legendary holding power. When the tape is removed, WD-40 is great for dissolving the gummy adhesive left behind.
- Removing labels from glass: Manufacturer labels in new windows, state park windshield stickers, sales labels on glassware...WD-40 is a go-to solvent from removing the adhesives used to stick these labels to glass.
- Protecting bike chains: Once or twice a year, spray the metal chain and gear sprockets on your bike. The thin oil will dissolve old grease and protect it from moisture. The oil is thin enough that it won't serve to attract grit and dirt, the way heavier oils do. WD-40 is not, however, designed as a lubricating oil. Various silicone products designed for bike chains are better choices.
- Polishing chrome: Rubbing a thin coat of WD-40 onto chromed metal surfaces will prevent moisture from pitting the metal.
Everyday users of WD-40 are constantly inventing new uses for the product, many of which the company doesn't officially recognize:
- Removing rings from your fingers: Have you ever found it hard to remove a ring once you put it on? A squirt of WD-40 will do the trick.
- Waterproofing boots and gloves: Spray WD-40 on outdoor wear to make it water-resistant. Amazingly, WD-40 is an effective and low-cost way to make boots, gloves, and other items more resistant to water. Spray it on before you go out in snow or rain.
- Removing stains on porcelain: Use it in the toilet to remove stains, or spray it on surfaces to remove tea or coffee rings, and more.
- Sprayings an insecticide or insect repellant: You can spray WD-40 directly onto insects to kill them or use it on surfaces to prevent insects from entering the house or building nests.
- Loosening stuck zippers: Metal zippers sometimes get sticky because the metal develops a bit of rust. WD-40 will loosen a metal zipper right up. Don't try this trick on plastic zippers, however.
- Moistening leather or wood: Because it lubricates and protects against moisture, WD-40 can help to keep guitar strings, baseball mitts, and even garden tools from drying or cracking.
- Lubricating a shovel: Digging in hard clay with an old shovel can be back-breaking work. Lubricating the shovel blade with WD-40 will make it slippery as it penetrates hard soil.
- Dissolving chewing gum: Hardened chewing gum can be impossible to remove—unless you use WD-40 to dissolve it.
- Lubricating guitar strings: Many musicians successfully use WD-40 to lubricate and protect guitar strings.
- Degreasing barbecue grills: As a preliminary part of deep cleaning, WD-40 will help dissolve the heavy, baked-on grease. Just make sure to remove all traces of WD-40 before lighting up your grill.
- Lubricating metal slides: Metal slides on backyard playground equipment can be polished to a high degree of slipperiness by rubbing it with a very fine coat of WD-40. Make sure to wipe off all excess oil.
- Loosening stuck legos: Lego toy pieces that are tightly stuck together can be loosened by spraying WD-40 into the cracks. But the pieces will be oily to the touch afterward, so make sure to wash, rinse, and dry them before handing them back to the kids.
When NOT to Use WD-40
- Don't use WD-40 on locks. While it's tempting to think you can lubricate a dry lock with oil, it will attract small particles of dirt and make the lock worse over time. Instead, use graphite powder.
- Don't use it to lubricate rubber or plastic parts. These parts are made of petroleum substances, and WD-40 may melt them.
- Don't lubricate computer keyboard keys. WD-40 can damage plastic parts inside the computer.
- Don't use WD-40 as a lighter fluid: WD-40 is flammable, and some users have attempted to spray it on bonfires or a charcoal grill to coax flames along. This is a very bad idea.
The WD-40 Safety Data Sheet notes that WD-40 is an extremely flammable aerosol and that the can may explode if it is heated. Further, WD-40 is highly poisonous and can be fatal if ingested or inhaled.
- Protect the can from direct sunlight, and do not store at temperatures higher than 122 degrees Fahrenheit
- Call a Poison Center if the product is ingested or inhaled. NO NOT induce vomiting.
- Dispose of old WD-40 in accordance with local and national regulations.