What is Powder Coating?

Powder coating is a dry finishing process where a fine powder (made of resin, pigment, and additives) is electrostatically sprayed onto a metal surface, then cured in an oven.

Instead of liquid paint, the powder melts and forms a tough, uniform coating that bonds strongly to the metal.

The benefits?

When you powder coat pre-galvanised steel fencing (steel already coated with zinc), you get a dual-layer protection system:

1. Superior corrosion resistance

• Galvanising (zinc layer) protects the steel underneath
• Powder coating seals the surface, preventing moisture and contaminants from reaching the zinc
• Result: much longer lifespan, especially in coastal or high-moisture environments

 2. Improved aesthetics

• Smooth, even finish (matte, gloss, textured, etc.)
• Wide colour range (e.g. Colorbond-style colours popular in Australia)
• Hides the sometimes dull or patchy look of raw galvanising

 3. Increased durability

• Resistant to chipping, scratching, and fading
• Better than conventional paint for impact resistance

 4. Weather and UV resistance

• Designed for outdoor exposure
• Maintains colour and finish over time

 5. Low maintenance

• No need for frequent repainting
• Easy to clean

 This combination is often called a “duplex system”, and it can last 2–3× longer than galvanising alone.

One Step Further?

Applying a zinc-rich primer system like Interpon Redox Metalprep before the powder topcoat takes performance up another level:

 1. Enhanced adhesion

• Pre-gal steel can sometimes be tricky for coatings to bond to
• The primer creates a chemical and mechanical bonding layer
• Reduces risk of peeling or delamination over time

 2. Triple-layer corrosion protection

You now have:

1. 1. Zinc galvanising layer (sacrificial protection)
   2. Zinc primer layer (additional barrier + cathodic protection)
   3. Powder topcoat (seal + UV protection)

 This dramatically improves performance in harsh environments (coastal, industrial, polluted areas)

 3. Improved cut-edge and damage protection

• If the coating is scratched or chipped
  • The zinc primer still helps protect exposed steel
  • Slows down corrosion creep from damaged areas

 4. Better performance in coastal / aggressive environments

• Salt spray resistance is significantly increased
• Ideal for fencing near the ocean (very relevant in many parts of Australia)

 5. Reduced risk of “outgassing” defects

• Galvanised steel can release gases during curing
• Proper metal prep + primer helps minimise bubbling/pinholes in the finish

 6. Longer coating system life (lower lifecycle cost)

• Extends maintenance intervals
• Often meets architectural or warranty-grade specifications

Bottom line

• Powder coating alone = strong, durable, attractive finish
• Powder coating on galvanised steel = excellent long-term protection
• Add a zinc primer like Interpon Redox Metalprep = premium, high-performance system suitable for Australian conditions