Flo-Coat 50 galvanized steel tubing is the product of choice for carports and other portable buildings. The unique, in-line Flo-Coat process provides a triple layer of corrosion protection that stands the test of time.

The process begins with flat strip steel, which is cold-formed and electric-resistance or induction welded. After welding, the tube goes through three coating baths. The first coating bath bonds zinc to the hot tubing, and is followed by a conversion coating. As the tub goes through the conversion coating bath, the process chemically changes the zinc already on the surface of the tube. The compounds which are formed make the zinc even less subject to corrosion than unprotected zinc. This conversion coating also provides another layer of protection for longer resistance to white rust corrosion. The excess solution is then removed from the tube and the tube is dried to prepare for its third and final protective coating bath... an application of a clear organic polymer to give the tube superior corrosion resistance, added aesthetic appeal, and long-lasting surface brightness. This coating is then cured to a smooth, hard finish near the end of the in-line process.

The result is a smooth, shiny end product appearance that is unmatched in terms of strength and durability - it will not oxidize or "gray down" with age, nor will the coating flake off during fabrication operations.

We guarantee a minimum 50,000 psi yield strength with our Flo-Coat 50. Our competition...pregalvanized tube products, i.e. G-60, G-90, G-120, etc., advertise only a "target" yield strength...not a guaranteed minimum yield strength.

The Flo-Coat manufacturing process not only protects the tubing, it also further strengthens it. The cold-forming, then heating and quick cooling of the tubing, enhances the mechanical properties - providing increased structural rigidity and greater impact resistance.

Corrosion Resistance Superiority

More than Double the Performance vs. Pregalvanized Tube Flo-Coat 50 tubing provides outstanding corrosion protection because of the synergism created between the three coatings. The conversion coating passivates the zinc to slow down the white rust growth, and the clear topcoat then "seals in" the protection.

Pregalvanized products do not provide this "sealed" protection. On the inside of Flo-Coat 50 tubing a corrosion-resistant zinc based coating is applied after the tube is welded, and completely covers the interior. When pregalvanized steel is formed and welded, the inside weld area is left bare - unprotected since the interior cannot be re-metalized. The exposed metal is immediately left to be attacked by all corrosive elements. The exterior of the weld is re-metalized, but is still far more susceptible to corrosion than Flo-Coat 50 tubing.

Flo-Coat products have several advantages over pregalvanized products when performing secondary operations:

• Allied utilizes a special high-grade 99.9% pure zinc material (meeting ASTM B-6) which contains only a trace amount of lead. Pregalvanized products typically have much higher lead content levels. By having the lowest lead content achievable, Allied zinc products can keep hazardous fumes generated during welding to an absolute minimum.
• Many pre-coated products contain aluminum in the coating which hardens with age. Fabrication must therefore be minimized to eliminate coating separation from the substrate. Flo-Coat 50 tubing withstands the bending and forming required for metal structures without flaking or chipping.
• Allied´s manufacturing process delivers uniform mechanical/physical properties on a consistent basis. This consistency (especially during bending operations) allows the manufacturer/fabricator to save a great deal of time and money during tube processing operations. The resulting savings mean lower overall production costs.
• Unlike Our products, tubing manufactured from pre-coated steel coils/sheets require special surface treatment prior to the application of paints or powder coatings; otherwise, proper adhesion is not obtained. These pre-treatments may include phosphating, anodizing or use of a conversion coating or special primer. Whichever process is utilized, it will add cost to the end product and possibly generate hazardous waste materials. Furthermore, a re-metalized weld seam on the OD will have different characteristics than the rest of the tube surface, and can result in poor adhesion of paint or powder to that area of the tube.

When welding any galvanized tubing, it is important to restore the corrosion resistance of the weld zone to that of the surrounding tube area. This is easily accomplished by using custom touch-up paint, which has been specifically designed for this purpose. Another method of restoring corrosion resistance is thermal spray. Thermal spray is a process by which zinc wire is continuously melted and projected by compressed air onto a prepared surface. If you would like more in-depth information on welding galvanized steel tubing, or the various methods of restoring corrosion resistance to weld areas, please contact us for a copy of the Welding and Painting Guidelines.