Banker Wire offers wire mesh in two types of Pre-Galvanized wire; “Regular coating” and trademarked “Galfan”. The term pre-galvanized means that the wire already has the zinc coating applied to it prior to the manufacture of wire mesh. This is different than “Galv-after” where the galvanizing is done after manufacturing in a tank of molten zinc. Also known as “Hot Dip” galvanizing, the entire finished product emerges from the molten tank fully coated with a layer of zinc.
Regular coating “Pre-Galv” wire is carbon steel which has been coated with a very thin layer of Zinc during the wire drawing process. Pre-galv wire is only slightly more expensive than plain steel wire, but offers improved corrosion resistance. Pre-galv wire is a great base material if considering a wire mesh with a powder coated finish in an exterior application.
Considerations when specifying Pre-Galv wire mesh:
For exterior powder coated wire mesh applications, pre-galv wire should be specified so that there is a layer of zinc protecting the bare steel under the wire intersections. The powder coating process does not fully cover this area of the wire mesh, which is why the pre-galv wire is recommended.
The corrosion resistance offered by zinc is good, but the thicker the coating the longer it will take for the zinc layer to corrode away leaving the bare steel unprotected. With pre-galv wire, the coating is very thin and not really suitable as a long lasting stand-alone finish for exterior applications. The performance however is greatly increased when used under a powder coated finish.