5 Ultimate Guides to Rust-Proofing Professional-Grade Outdoor Lighting

Why Waterproofing and Rust-Proofing Are Game-Changers for Outdoor Lighting？

If you’ve been in the outdoor lighting wholesale business for more than a season, you’ve probably seen it: a beautiful lamp shipped to a coastal resort, only to develop rust spots in a matter of months. Or a “waterproof” light that failed after its first heavy rain.

In the US and Europe, outdoor lighting is not just about aesthetics — it’s about durability. Buyers in Florida, the Mediterranean, or Australia’s coastal regions know that salt air, humidity, and UV exposure can silently eat away at even the most stylish fixture. Understanding why rust forms and how to prevent it is the first step toward building trust with your customers — and protecting your bottom line.

Rust is no accident. Rust is essentially the product of an electrochemical reaction between metals under the action of oxygen, moisture, and electrolytes (such as salt). This problem troubles most outdoor lighting users. Follow XINSANXING's footsteps to learn the real cause of rust and professional solutions.

1. Improper metal material: Low-carbon steel or ordinary iron parts without a protective coating on the surface will quickly react with oxygen in the air, causing rust.

2. Damaged surface coating: Scratches on the paint surface during transportation and installation, rainwater penetrating into the iron parts, and failure to dry them in time will also corrode the substrate.

3. Salt spray corrosion: Salt ions act as "catalysts". The high concentration of salt ions in the air in coastal areas (the salt concentration in coastal areas can be 5-10 times that of inland areas) accelerates the pace of rust. Even non-marine grade (316) stainless steel can develop rust stains.

4. Condensation: Inadequate internal waterproofing of the lamp body. When there's a large temperature difference between the inside and outside, condensation forms inside the lamp body, creating fog. This moisture, unable to escape for extended periods, accelerates internal corrosion and is a hidden "killer."

5. Electrochemical corrosion: When dissimilar metals (such as aluminum and stainless steel) come into direct contact in a humid environment, a potential difference creates an electrolytic reaction within the lamp body, accelerating corrosion. This is often overlooked.

Air humidity > 60% + temperature 0–35°C: Oxidation is most likely to be triggered.

ASTM B117 salt spray test for 500 hours ≈ equivalent to six months of outdoor use in coastal areas.

The good news? With the right materials, designs, and handling practices, most of this can be avoided.

For coastal resorts in Florida or Spain, marine-grade 316 stainless steel (2–3% molybdenum) offers superior resistance to chloride corrosion.

For lightweight yet strong designs, powder-coated aluminum (6061/6063) with a 60–100 μm coating gives excellent UV and salt resistance.

Heavy-duty structural parts, Hot-dip galvanized steel with ≥70 μm zinc coating is your friend.

And for woven-style solar lamps, UV-stabilized synthetic rattan or polycarbonate ensures color stability and avoids brittleness.

Salt Spray Test (ASTM B117 / EN ISO 9227): Common acceptance criteria: 500–1000 h, no red rust (depending on project level). UV aging resistance (ASTM G154): No noticeable yellowing or embrittlement after 500 hours, superior to typical decorative components.

Waterproofing becomes simple if the following key details are addressed.

IP Rating: For outdoor use, IP65 is generally recommended (perfect for withstanding heavy rain). For applications involving prolonged submersion in water, such as pools and fountains, IP67/IP68 is recommended.

Sealing Ring Material: Silicone is preferred, with a temperature resistance of -40°C to +200°C and good compression resilience; a compression of 15–30% is recommended.

Breaking Air/Drainage: Invisible drain holes or a breather valve (ePTFE/Gore Vent) are designed on the bottom to address both condensation and pressure differentials.

Cables and Wiring: Use IP68 cable connectors and designate curved drip lines to prevent water intrusion.

Packaging and Storage: Apply moisture-proof film to outer boxes, include 30–60g of desiccant per box, maintain a warehouse humidity of 50–60% RH, and provide humidity indicator cards.

Avoid contact between dissimilar metals: As mentioned above, chemical corrosion can occur between dissimilar metals, so nylon washers/spacers should be placed between dissimilar metals (such as stainless steel screws and aluminum parts).

Mounting Location: Avoid areas with accumulated water or areas directly exposed to strong spray. Quarterly salt spray flushing is recommended for coastal projects.

Fasteners: For outdoor installations, A2/304 or A4/316 screws are preferred. Tighten to the required torque to avoid scratching the surface coating.

Red Line: Any areas where paint has been chipped by metal parts during transportation must be repaired promptly. If not repaired, rust will likely develop later.

Taking these protective measures can significantly reduce the likelihood of rust on lamps, but of course, this doesn't completely eliminate the risk. Manufacturers generally offer warranty policies, so choosing a suitable and trustworthy outdoor lighting manufacturer is crucial. XINSANXING is a good choice.

Even the best products may develop minor rust over years. Knowing how to respond protects your brand.

Light surface rust: Sand with 600–800 grit, clean, dry, and apply protective oil/wax.

Localized pitting: Apply phosphoric acid gel for 10–20 minutes, neutralize, then coat with zinc-rich primer (>90% zinc) before repainting.

Structural corrosion: Replace the equipment to avoid safety hazards.

Authentic and accurate test data and assurance are the cornerstones of global trade, especially in the United States and the European Union.

· IP Test Reports (IEC 60529) for ingress protection.

· Salt Spray Testing (ASTM B117 / EN ISO 9227) — 500–1000h with no red rust is common for quality outdoor lights.

· UV Aging/Weathering Report (ASTM G154/ISO 4892) — no yellowing or cracking after 500h.

· IK Impact Rating (EN 62262) — IK08+ for public areas.

· Offer 1–3 year limited warranties covering water ingress, coating failure, and rust, and include maintenance tips like quarterly freshwater rinsing in coastal areas.
· Pre-shipment inspection of appearance and functionality at AQL 1.5/2.5; sample comparison of key components.

Waterproofing and rust prevention are also part of wholesale competitiveness. This isn't something that only the technical department needs to worry about.

In the competitive market, the appearance of a lighting fixture is only of primary importance; weather resistance is the key to long-term sales. These details are the foundation of a brand's reputation and a key component of its competitiveness. Therefore, understanding the principles of rust formation, rust removal techniques, and rust prevention strategies can not only help wholesalers reduce return rates but also enhance their brand's professional image in the eyes of customers.

💬 To obtain our 2025 full-line IP65+ outdoor lighting wholesale catalog (including woven solar and beachfront project-specific models), contact our sales team for complete product testing data and samples.