Penetrants are indispensable allies for maintaining and repairing mechanical parts. Whether dealing with rust, dirt, corrosion, or a lack of lubrication, these products simplify the unblocking process and extend your equipment's lifespan. Here’s everything you need to know about penetrants, including how to choose the right one and the advantages of trusted products like WD-40.

Why use a penetrant?

Over time, metal and plastic components face various challenges:

Humidity: promotes rust and corrosion on unprotected metals.
Chemical exposure: salt and certain solvents accelerate metal wear.
Excessive friction: dirt buildup or insufficient lubrication can seize mechanisms.
Natural wear: even well-maintained parts can eventually become immobile.

A penetrant works by infiltrating rusted or blocked areas, reducing friction, cleaning residues, and protecting against future corrosion.

When to use a penetrant?

Rusty or oxidized parts: penetrants dissolve rust, prevent forceful applications that could damage parts, and protect against further corrosion.
Seized mechanical components: loosen bolts, nuts, hinges, padlocks, or gears by lubricating and reducing friction.
Preventive maintenance: regular application prevents oxidation and preserves chains, bearings, axles, and more.
Cleaning: some penetrants effectively remove grease, gum, wax, and other residues from metal, plastic, or rubber surfaces.

How to choose the right penetrant?

Material type :
- For metal : choose an oil-based penetrant for rust and corrosion.
- For plastic or rubber : use a silicone-based, non-aggressive formula.
Specific formula :
- Look for penetrants with additives for corrosion resistance or water repellency.
- Choose products designed for extreme temperatures if needed.
Test first : always test the penetrant on a small area to confirm compatibility.
Manufacturer’s advice : follow the product's instructions to ensure it suits your application.

WD-40 range : flagship penetrants

1. WD-40 super sealer

Ideal for heavily rusted or corroded parts like bolts, bearings, or conveyors.
Protects against corrosion for up to 30% longer within 72 hours.
Water-resistant and effective on most metals.
Operates between -20°C and +90°C.

2. WD-40 multifunction

Combines 5 uses: moisture repellent, anti-corrosion, degreaser, cleaner, and lubricant.
Penetrates rust and corrosion quickly.
Silicone-free formula reduces dust deposits.
Protects metal surfaces from moisture and oxidation.
Withstands extreme temperatures from -50°C to +150°C.

Recommendations for use

Shake before use: ensures active ingredients are well-mixed for maximum effectiveness.
Spray safely: apply from a distance and allow it to penetrate for several minutes.
Wipe excess: use a soft cloth to avoid drips and inspect the treated part.
Repeat if necessary: for severe rust or seizures, multiple applications may be required.

Conclusion

Penetrants are invaluable for maintaining the functionality and extending the life of mechanical parts. Whether loosening rusty bolts or performing regular maintenance, a high-quality penetrant can make all the difference. Products like WD-40 super sealer and WD-40 multifunction offer unparalleled versatility and efficiency. Choose your penetrant based on the materials and environmental conditions for optimal, long-lasting results.