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EDUCATION > Did You Know? > General > Cleaning and Pretreatments of Coated Metal

Cleaning and Pretreatments of Coated Metal

cleaning-pretreatment-coated-metal-th.jpgProper cleaning and pretreatment of metals are critical components of the high performance paint finish used for metal cladding. To obtain proper long term  performance of coatings, metal must be cleaned of any contaminants associated with the steel or aluminum processing/manufacturing. Pretreatments then convert the metal surface into a non-metallic coating to obtain proper adhesion by a chemical/physical bond, increasing the durability of both the base metal and paint finish by providing an additional barrier layer and protecting areas where damage to the paint may occur during the life of the cladding.

Types of Pretreatment Systems
Zinc Phosphates - used on hot dip galvanized steel
  • Provides increased corrosion resistance of galvanized steels
  • Used commercially for over 100 years
  • Evolutionary improvements
    • Use of additives and refinement of the process
    • Increased the durability of steel cladding that has difficult forming requirements
Complex Chrome Oxides - used on aluminum/zinc alloy coated steels and aluminum
  • Conversion coatings
  • Dried-in-place coatings
  • Excellent formability
  • Field-proven corrosion resistance to the base metals

New emerging technologies are forthcoming in the metal pretreatment industry. Some are already commercially available. The viability of these newer technologies is undergoing field studies to ensure time proven performance equal to previously identified processes which have been used successfully for many years.