1.Why not recommend it?
Continuous Immersion and Splashing:
The stage's supporting structure will be submerged in water, either intermittently or for extended periods, and subjected to splashing water from waves and performances.
This causes the zinc coating to remain in constant contact with oxygen-rich water, accelerating its depletion. Once the zinc coating is completely consumed, the underlying steel will corrode rapidly.
Electrochemical Corrosion (Critical Risk):
If different metal components of the stage (e.g., a galvanized steel frame with stainless steel screws, aluminum handrails, or underwater lighting) are in direct contact and immersed in an electrolyte (water), a galvanic cell will form.
In this environment, the galvanized coating may corrode abnormally quickly, resulting in a shorter lifespan than expected.
Mechanical Damage:
During assembly, disassembly, transportation, and use, the galvanized coating is easily scratched and damaged by impacts.
These points of damage become the starting points for corrosion, causing rust to penetrate inwards even if the surrounding zinc coating remains intact.
2.If we insist on using it, what measures must be taken?
Choosing the Right Materials:
Hot-dip galvanized coils/materials must be used, not electro-galvanized coils with a thinner zinc layer. Hot-dip galvanizing provides a thicker zinc layer (typically ≥85µm), offering longer protection.
A higher zinc layer weight is required (e.g., ≥275 g/m²).
Strict Post-Processing Protection:
All cuts, drilled holes, and welds must be thoroughly treated immediately with anti-corrosion measures. Standard practice is:
Grind and clean the welded areas.
Apply a zinc-rich primer with a sufficiently high zinc powder content to simulate the "cathodic protection" effect of galvanizing.
Apply a high-performance intermediate and topcoat (e.g., epoxy or polyurethane paint).
Structural Design:
Avoid areas prone to water accumulation during the design phase. Pipe ends must be sealed with end caps to prevent moisture buildup and subsequent corrosion from the inside out.
When connecting to other metals (e.g., stainless steel, aluminum), insulating gaskets or sleeves must be used to prevent galvanic corrosion.
3.What are the advantages and disadvantages of using aluminum alloys as a substitute?
Advantages: Extremely corrosion resistant, especially in freshwater environments. Lightweight and high-strength, making it very easy to assemble and move. No painting required, resulting in extremely low maintenance costs.
Disadvantages: Higher initial cost than steel. While strong, it is less rigid than steel, sometimes requiring a larger cross-section to prevent deformation.
4.What are the advantages and disadvantages of stainless steel as a substitute?
Advantages: Excellent corrosion resistance and high strength. Especially 316 marine-grade stainless steel, which has very strong resistance to chloride ion corrosion, making it ideal for seawater or high-salt environments.
Disadvantages: Highest cost, heaviest weight, and most difficult to process.
5.How effective are professionally anti-corrosion treated steels?
Employing a "heavy-duty anti-corrosion coating system," such as epoxy zinc-rich primer + epoxy micaceous iron oxide intermediate coat + polyurethane topcoat, offers a significantly longer corrosion protection lifespan than a single zinc plating layer.
Alternatively, chromium-free zinc-aluminum coating technologies such as Dacromet can be used, providing corrosion protection far exceeding that of hot-dip galvanizing.