There are two types of surface finish for welded mesh, Galvanized After Welded (GAW) and Galvanized Before Welded (GBW). It is well known that GAW mesh offers advantages that make it superior to the GBW mesh. The reason lies in the way they are processed.
GAW – After welding is completed, the mesh is dipped into a bath of molten zinc. The zinc bonds to the wire’s surface, evenly sealing it and preventing it from rust and corrosion.
While for the GBW mesh, the galvanized layer can be burnt away at the intersecting area, leaving the wire unprotected, which will get rust easily.
So if you will use the welded mesh in a harsh environment, the galvanized after welded mesh is a better solution.