What Does Zinc Thermal Spray Mean?
A zinc thermal spray is a way to apply a zinc coating to a substrate material. A zinc thermal spray uses the thermal spraying process to adhere the zinc to the base material, as opposed to hot dip galvanizing, electrogalvanizing or other methods of galvanizing.
Zinc spray coatings help protect base materials from corrosion. Molecules of zinc are more likely to oxidize than many other types of metals. Since zinc has a proclivity to oxidize first, it limits the oxidation of the other metals in contact with it.
Corrosionpedia Explains Zinc Thermal Spray
As the name implies, a zinc thermal spray uses the thermal spray process, which for zinc spraying applications is either wire arc thermal spray or flame thermal spray.
- Flame thermal spray involves using a torch with a combustible gas to heat a wire or powder and then using compressed air to project this melted zinc onto the base material.
- Wire arc thermal spray uses an electrical arc to melt two zinc wires. The two zinc wires serve as both the consumables and the electrodes. Once the arc is created, compressed air is used to project it at the base material.
Zinc spray coatings are typically not as easily controlled as other galvanizing processes. The coatings are typically thicker, have less bonding strength and less abrasion resistance. Also, the resultant coating from zinc thermal spray is heavily dependent on operator skill.
Despite its limitations, zinc spray is an excellent option when the material being coated is in a remote location or is too large to be coated by other galvanizing processes.