Where should WD40 not be sprayed?
3 Answers
WD40 should not be used on rubber, plastic, or wax surfaces in cars. WD40, known as a moisture-displacing and rust-preventing lubricant, must not be sprayed on areas of the car that have rubber, plastic, or wax. Although WD40 rust remover is powerful and versatile, it is not a universal solution and can have adverse effects on certain materials. Specific functions of WD40: Cleaning: WD40 can thoroughly remove stubborn stains adhering to metal surfaces, making it particularly suitable for cleaning pneumatic tools like nail guns. Moisture removal: Since WD40 can eliminate moisture and water, it quickly dries electronic systems, preventing short circuits caused by humidity. Penetration: WD40 can remove rust that binds metals together, freeing stuck, frozen, or rusted metal parts. Lubrication: WD40's lubricating components spread evenly and adhere firmly to movable parts. Protection: WD40 contains anti-corrosion ingredients that protect metal surfaces from moisture and other corrosive factors.
As a seasoned DIY enthusiast, I've accumulated extensive experience using WD-40. Remember, never spray it into keyholes—the lubricant attracts dust and debris, which can eventually clog the lock cylinder, making it harder to open and costly to repair. Avoid spraying on electrical components like plugs or switch interiors, as the oil-based formula may cause current leakage, short circuits, or even fire hazards. Rubber parts such as door seals or handles will age and become brittle faster when sprayed, turning flexible materials prone to cracking and hardening. High-temperature areas like engine exhaust systems are extremely dangerous—spraying can easily ignite flames. Don't risk using it on food-contact surfaces like utensils; WD-40 isn't food-safe, and residues can contaminate food. Painted surfaces are also off-limits, as it may corrode the finish and leave unsightly marks. I only use it for lubricating metal joints or rust removal—safety always comes first.
As a seasoned auto mechanic, I've seen too many people misuse WD-40. Spraying oil into lock cylinders attracts dust, jamming internal mechanisms and making future unlocking extremely difficult. Electrical components like wire connectors or onboard electronics can suffer circuit failures or shorts when oil seeps in. Rubber bushings such as suspension seals swell and crack when soaked, compromising vehicle structure. High-temperature parts like exhaust pipes operate at extreme heat – spraying them risks ignition, causing burns or worse. Interior plastic parts fade and become brittle when treated, ruining aesthetics. Near brake systems like calipers, oil contamination may cause dangerous brake slippage or failure. Also avoid car body paint as it accelerates rust through corrosion. Recommended only for nut/bolt lubrication – steer clear of these no-go zones. Always inspect before garage visits.
