Architectural Metal Coatings

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Applying Spray Duranar® to Steel

We are often asked for recommendations relative to application of Spray Duranar® on steel.  The wide variety of steel types and pretreatment systems available in the market make it impossible to test every scenario and there is not an industry specification to follow such as AAMA for the aluminum industry.

The following guidelines should be followed to insure the best possible end result:

 

  1. Steel - The recommended substrate is hot dip galvanized.  Raw steel or cold rolled steel does not provide adequate corrosion protection.Stainless steel has proven very difficult for adhesion and should be tested to confirm proper results.
  2. A multi-stage cleaning and pretreatment should be used.Apply a minimum of 200 mg of Zinc Phosphate treatment. (Contact your pretreatment supplier for specific cleaners, temperature, and dwell time.)
  3. Pre-bake treated metal to eliminate moisture from porous surfaces (dry-off may need to be lengthened compared to Aluminum substrates.)
  4. Apply UC51742 Duranar Flash Primer at 1.0 +/- 0.20 mils and cure at 450° F metal temperature for five minutes. This will allow the applicator to measure the primer DFT and check for gassing or voids before top-coating.
  5. Apply the Spray Duranar® topcoat at the standard film build and bake 5 minutes @ 450F PMT.
  6. Post forming, drilling, and cutting should be avoided to minimize raw steel edges which will corrode.
  7. Seashore exposure should be avoided.
  8. PPG offers no warranty for Spray Duranar® on steel.
  9. Coraflon ADS (Air Dry System) fluoropolymer is also available and based on the proper procedure can be warranted.Please refer to the Touch Up and Restoration section on the website for further information on this product.