What Does Inorganic Zinc Primer Mean?
An inorganic zinc primer is a type of coating, comprised mostly of zinc, which is applied to bare metal either by itself or prior to subsequent coatings. An inorganic zinc primer uses a silicate binder to create adhesion on the metal's surface. The silicate binder, as opposed to other types of binders, is why this type of zinc primer is considered inorganic.
Inorganic zinc primers protect certain base materials from the detrimental effects of corrosion.
Corrosionpedia Explains Inorganic Zinc Primer
Perhaps the most common base material coated with an inorganic zinc primer is steel. Corrosion protection is provided in two ways:
- It creates a layer between the steel and potentially corrosive substances.
- Through cathodic protection. Zinc is more reactive than steel, which causes the zinc to oxidize more readily when placed in the same electrochemical cell, thus preventing the steel from corrosion.
There are two major types of zinc primers: inorganic and organic. Inorganic zinc primers use silicates to adhere the zinc onto the surface of the base material, whereas organic zinc primers use binders such as epoxy resins.
Inorganic zinc primers are known for their ability to contain higher amounts of zinc than other types of zinc primers. This typically allows inorganic zinc primers to have superior corrosion resistance than their organic counterparts. It should be noted, however, that inorganic zinc primers must have a base metal that has been thoroughly prepared for coating; therefore its low tolerance for poor surface quality may make organic zinc primers a better alternative for field applications.