Pacific Galvanizing: Hot Dip Galvanizing
The Hot Dip Galvanizing Process is the most effective economic and widely used process for corrosion prevention.
Hot Dip Galvanizing provides a durable, long-lasting metalic zinc and alloy coating, metallurgically bonded to the base metal. Prepared items are coaated by immersion in molten coating, normally two ounces of zinc per square foot of surface area, corresponding to a coating thickness of 3.4mils.
The Molten zinc of the galvanizing bath covers corners, seals edges, seams and penetrates recesses to give complete protection to what are potential corrsion spots.
Rust, scale, oil and other surface contamiants are first carefully removed from steel work by pickling in dilute sulfuric acid.
In our galvanizing process prepared work is lowered into the bath of molten zinc though a floating layer of flux (Ammonium Chloride). The flux dissolves and absorbs any remaning impurities, mosture or oxide film on the metal surface and ensures that clean iron or steel contacts the molten zinc at the moment it enters the bath.
Upon immersion in the bath of the surface of the iron or steel article is immediately wetted by the molten zinc and reacts to form zinc-iron allow layers. To allow formation of the galvanized coating the work remains in the bath untill it's temperature reaches that of the molten zinc, 850F. The work is withdrawn from the zinc bath at a controlled rate and carries with it a coating of molten zinc which solidifies to provide the relatively pure outer zinc coating. The result is a tough, combined zinc and zinc iron alloy coating, metallurgically bonded to and completely covering the base iron or steel.
Visual inspection is the simplest and most important means of assessing the quality of Hot Dip Galvanized Coatings. This servers to pick out superficial defects and can give information about faults in the process. The coating must be smooth, reasonably bright, continuous and free from imperfections such as flux, ash and dross inclusions.
Also used is a magnetic balance gauge which has the advantages of a counterbalanced magnet which allows used in any position without interference from gravity, and provision for recalibration for consistently accurate results. In operation the resistance of the magnetic tip to withdraw from the coating surface gives a coating thickness reading on the measuring wheel.
It is sometimes necessary to touch-up or repair galvanized coatings. Zinc-rich paint is used to give very good protection by using an exceptionally smooth flowing bright galvanizing compound that leaves a 93% bright metal dry film coating.
All material is stacked in our yard on pallets or wood blocks until time to ship. Forklifts are used to load and unload the materials from trucks.
