Anti-rust Treatment for GRC Curtain Wall to Steel Structure Connections: Durable Connections and Qinglong Group Anti-corrosion Process Standards

Anti-rust treatment of the connections between GRC curtain walls and steel structures (such as steel keels and steel transition fittings) is the lifeline for ensuring the long-term durability of the curtain wall system, and must follow the four major principles of "preferred metal materials, surface treatment meeting standards, insulating isolation at contact points, and reserved maintenance access". Qinglong Group's standard process stipulates: connection steel components exposed outdoors or in damp cavities must undergo hot-dip galvanizing (average zinc coating thickness ≥85μm); critical areas adopt a composite coating system of "hot-dip galvanizing + epoxy zinc-rich primer + fluorocarbon topcoat"; when different metals (such as stainless steel bolts and galvanized steel components) come into contact, insulating gaskets (such as nylon gaskets and plastic sleeves) must be installed to prevent electrochemical corrosion; and all connection nodes must remain accessible for future inspection and maintenance. In the Shenzhen Yirui Biotech Building project, we strictly implemented this standard; an open-box inspection after ten years of use revealed no signs of rust at the connection points. Anti-rust treatment is concealed work, but it determines the longevity of the surface.

Surface Treatment of Steel Substrates Is the Foundation of Protection

After fabrication, all steel components must undergo thorough surface rust removal to achieve Sa2.5 (near-white) cleanliness. Hot-dip galvanizing then follows, as the most economical and effective long-term anti-corrosion method. For components with complex shapes or oversized dimensions, arc-sprayed zinc/aluminum may be adopted. Qinglong Group conducts film thickness testing on every batch of galvanized components to ensure compliance.

Coating Protection and Insulation Treatment Are Reinforcement Measures

In coastal or highly polluted areas, anti-corrosion coatings are additionally applied over the galvanized layer to form dual protection. The coating system must be compatible, typically "epoxy zinc-rich primer + epoxy micaceous iron oxide intermediate coat + fluorocarbon/polyurethane topcoat". The key step is insulation between different metals; we use custom nylon washers and insulating coatings between stainless steel and carbon steel to completely cut off the galvanic corrosion circuit.

Structural Design Creates Favorable Conditions for Rust Prevention

The design avoids dead corners where water or dust can accumulate. Connections are exposed as much as possible or fitted with inspection openings to facilitate later observation and maintenance. Fasteners should be tightened with a torque wrench to avoid coating damage from overtightening and fretting wear from under-tightening. We provide detailed anti-corrosion design specifications and construction process cards.

Corrosion at connection points is a slow but irreversible process. Qinglong Group treats anti-rust details with the most stringent standards, ensuring the curtain wall's skeleton remains strong for years to come.