Using Thermal Spray Coatings for Corrosion Control

The number of applications and the surface area to which a thermal spray is applied is increasing resulting from its maintenance-free and reliable active corrosion protection features. Zinc coatings are recommended for use in the 6-12 pH range and are much more resistant to hard than to soft water. Unlike a hot dip galvanized zinc coating, where a chemical treatment is necessary to achieve good adhesion to a paint system, the sandpaper-like surface and the microporosity of a thermal sprayed coating of zinc or aluminum is a perfectly prepared base for paint. Thermal spray involves the use of a torch to heat a material, in powder or wire form, to a molten or near-molten state and the use of a gas to propel the material to the target substrate, creating a completely new surface. While thermal spray technology (TSA) coatings are more expensive to apply then conventional paints, their total life cycle costs are far less because of their longer, maintenance-free, and more reliable service life.