Will Carbon Steel Solar Mounting Structures Rust? How to Protect Them?
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In the solar mounting industry, carbon steel is widely used for its strength, durability, and cost-effectiveness. However, one common question arises: Will carbon steel rust? And if so, how can we prevent it? Let’s explore.
Does Carbon Steel Rust?
Yes, carbon steel is prone to rusting when exposed to moisture, oxygen, and other environmental elements. Unlike stainless steel or aluminum, carbon steel lacks sufficient corrosion resistance on its own. Over time, unprotected carbon steel will develop surface rust, which can compromise both the structural integrity and appearance of the solar mounting system.
Why Still Use Carbon Steel for Solar Structures?
Despite its susceptibility to rust, carbon steel remains popular in solar racking systems for several reasons:
High strength-to-weight ratio
Lower material cost compared to aluminum and stainless steel
Good load-bearing capacity for ground mount and large-scale projects
Easy fabrication and installation
To maximize its advantages, it’s crucial to apply effective anti-corrosion treatment.
Protection Methods for Carbon Steel Structures
Here are the most common and effective surface treatments used in the solar industry:
1. Hot-Dip Galvanizing (HDG)
A thick layer of zinc is applied by immersing steel in molten zinc. HDG offers:
Excellent long-term corrosion resistance
Self-healing capability at cut edges
Typical zinc coating thickness: 65μm to 85μm
Ideal for outdoor and coastal installations
2. Zinc-Aluminum-Magnesium (ZAM) Coating
ZAM is a newer type of coating offering:
Superior corrosion resistance (up to 2-3 times better than HDG in salt spray tests)
Thinner coating with better surface finish
High-performance protection in aggressive environments
3. Powder Coating or Epoxy Painting
These coatings offer both protection and aesthetics:
Applied electrostatically and cured under heat
Often used for custom colors or secondary protection
Requires good surface preparation to ensure adhesion
Additional Tips for Corrosion Prevention
Avoid water traps in the design (open profiles, drainage holes)
Use compatible fasteners (e.g., stainless bolts with HDG steel)
Apply touch-up spray (zinc-rich paint) on cut edges during installation
Choose suitable protection based on climate (desert, seaside, humid areas)
Conclusion
Yes, carbon steel can rust—but with the right surface treatment such as hot-dip galvanizing or ZAM coating, it becomes a reliable and long-lasting material for solar racking systems. When designed and protected properly, carbon steel structures can serve your solar project for 20+ years, even in harsh environments.
If you're looking for a durable, cost-efficient, and well-protected steel pv mounting system, carbon steel with advanced anti-corrosion treatment is a strong choice.