Egoza razor wire is available with two types of corrosion protection coatings: traditional hot-dip galvanized zinc and modern aluminum-zinc alloy (55% Al, 43.4% Zn, 1.6% Si). The difference lies not only in the price but also in the protection mechanism against salt spray exposure.
Chemistry and Passivation
- Zinc – cathodic protection: the sacrificial layer dissolves, shielding the underlying steel.
- Al-Zn – aluminum forms a barrier film + zinc provides cathodic protection; dissolution occurs 2-3 times slower.
Salt Spray Chamber Testing
At 35 °C and 5% NaCl:
- Zinc 250 g/m² – white corrosion appears after 350 hours, red corrosion after 900 hours.
- Al-Zn 185 g/m² – first white spots appear after 1100 hours, red corrosion after 2400 hours.
Lifecycle Cost Analysis
Considering repainting every 10 years, the total cost of a zinc-coated barrier over 30 years is 18% higher.
When Is Zinc Justified?
- Dry climate, located more than 20 km from the sea.
- Temporary fencing with a service life of up to 10 years.
- Projects with strict CAPEX limits and no OPEX contracts.
When to Choose Al-Zn?
- Ports, oil depots, offshore wind farms, and salt ponds.
- Service life 25 years without repainting.
- Temperature cycles from -40 to +60 °C (aluminum reduces cracking risks).
5-Second Cheat Sheet
Al-Zn is more expensive initially but cheaper in the long run; zinc makes sense for temporary barriers or installations far from coastal areas.