Duplex Corrosion Coating System

Duplex Corrosion Coating System: How it Works. How it’s Applied.

| August 30, 2018duplex corrosion coating system,

For a severely corrosive environment, the duplex corrosion coating system ensures an extended productive life for iron and steel assets, along with an extended maintenance cycle.

Two corrosion protection methods are better than one. That’s the theory behind duplex protective coating systems, which combine the proven protection of galvanization with the benefits of an additional corrosion protection system, such as polymeric powder coating. Using two coatings, one above the other, can improve a substrate’s ability to withstand the attack of corrosive substances in the working environment and extend the productive life of assets. Duplex systems can also extend the maintenance cycle in some cases, thus improving ROI over a project’s life cycle.

How Duplex Systems Provide Additional Corrosion Protection

While the zinc-iron alloy created in a galvanized coating performs as a primer and becomes an impervious barrier film for the steel substrate, when a special polymeric coating is also added, the corrosion protection can be extended from 1.5 to 2.5 times the arithmetic total longevity of the two individual systems. In other words, if you have a polymer coating system that lasts 10 years and a hot-dip galvanized system that’s expected to last 50 years for a total of 60 years (50 years + 10 years), the duplex system would actually last 90–150 years. That is, if you allow both coatings to wear out completely.


Drizoro Maxrest®Passive 

  1. is a one-component liquid product, ready to use as an oxide converter and corrosion protection for reo / re-enforcing bars and other steel and iron surfaces against corrosion.
  2. neutralizes the corrosion process, reacting quickly with the rust and transforms iron oxide into a stable passive layer giving full protection against corrosion, salts, acid and alkali attack.
  3. Duplex corrosion coating with repair material such as Drizoro Maxrite 700– fibred cementitious mortar + corrosion inhibitor
  4. Using Drizoro Maxseal Flex as a waterproof membrane as part of a  duplex corrosion coating system

Demand for duplex coated steel occurs in the following sectors:

  • Specialty cladding material for residential, commercial and industry needs
  • Architectural products
  • Building and construction products
  • Automotive
  • Aviation
  • Appliance
  • Chemical
  • Petroleum

The Advantages of Duplex Corrosion Coatings

A duplex system of coating has the following benefits:

  1. Extended and enhanced corrosion protection. No other protection system matches this enhanced protection individually.
  2. Coating galvanized steel can provide an attractive aesthetic appearance, enabling the brightness and color of the steel to be matched to the specific location and environment.
  3. Because duplex systems significantly extend the productive service life of a steel product, maintenance expenses are reduced. As a result, total life-cycle expenses are also lower.
  4. Steel can be coated to comply with safety color regulations.
  5.  The zinc coating provides corrosion protection even when top coating is worn out. Repainting the structure again gives us the duplex system. The weathered zinc alloy on the surface facilitates repainting with minimal cleaning.
  6. Maintaining the top coat means the first coat remains protected.


Drizoro Maxrest®Passive – duplex corrosion coating system

  1. is a one-component liquid product, ready to use as an oxide converter and corrosion protection for reo / reinforcing bars and other steel and iron surfaces against corrosion.
  2. neutralizes the corrosion process, reacting quickly with the rust and transforms iron oxide into a stable passive layer giving full protection against corrosion, salts, acid and alkali attack.
  3. Duplex corrosion coating with repair material such as Drizoro Maxrite 700– fibred cementitious mortar + corrosion inhibitor
  4. Drizoro Maxrite®700 is waterproof
  5. Using Drizoro Maxseal Flex as a waterproof membrane forms the THIRD layer of protection improving on the duplex corrosion coating system

Duplex Systems for Corrosion Protection
Duplex Systems for Corrosion Protection provide better corrosion protection and reduce maintenance costs. This is not to suggest the original paint or powder coating will last more than a century.
Lifetime assumes no maintenance will be performed and the paint or powder coating would naturally wear way. Then the galvanizing would provide corrosion protection for the remainder of the life.  However, the owner will likely want to maintain the paint/powder system for aesthetics.
So in practice, the synergistic effect is realized in the delayed maintenance cycle (touch-up, maintenance paint, and full repaint) of the paint/powder coating of the duplex system.  The maintenance cycle paint/powder on galvanized steel is 1.5 to 2 times the cycle for paint/powder on bare steel

Duplex Systems for Corrosion Protection,

https://galvanizeit.org/corrosion/corrosion-protection/duplex-systems