Project specification requirements for paintgrip or mill-phosphatized finishes added to the galvanized coating for exposed ductwork have the ultimate intentions of providing a paintable surface. In theory the “acid” etching of the surface is to provide additional “bite” to the paint and enhances the adhesion of the paint to the underlying surface.

Today’s high quality latex DTM (Direct-To-Metal) paints do not require any surface treatment to the galvanize surface other than it be clean and oil free of petroleum based lubricants.

As a standard practice galvanized sheet metal comes from the mill with a very light coating of petroleum based oil due to the manufacturing process. Regardless of the additional surface finish that is specified this layer of oil must be removed in order for the latex base paint to properly adhere to the surface.

Linx Industries, as a standard practice, orders all galvanize material as chem-treat dry and oil free. In addition we use water based lubricants throughout the manufacturing process; resulting in a paintable surface without any other additional treatment. All you need to do is to insure any accumulation of surface dirt is remove using Simple Green or similar products.