Bare steel will rust in a couple of days when exposed to the elements. To prevent this, it is necessary to coat the surface of the bare steel. Most steel building manufacturers use red oxide primer on all structural steel components. There are some that use light gauge galvanized secondary steel as the standard material and leave the heavy frames rigid with a red oxide primer. So what is the difference between the two and are there any advantages to galvanized secondary steel?
For most applications, red oxide primer is more suitable than a galvanized finish. This is why red rust is used in most commercial and agricultural construction, from backyard sheds to the tallest skyscrapers. Of course, there are some cases where galvanizing is recommended. Galvanizing can be useful in corrosive environments such as chemical plants or coastal roofing systems. There are different grades of galvanizing with different associated costs. Good quality galvanizing is expensive and turns a versatile material into a very unforgiving material. Galvanized steel cannot be painted, bent without cracking the finish, or welded without producing toxic fumes. Since a galvanized part cannot be painted, modifications cannot be covered. It is also extremely abrasive and must be handled carefully with gloves at all times. Galvanized steel is not resistant to rust when exposed to moisture. Galvanized steel will usually develop white rust that can be unsightly. Red rust primed steel can also develop surface rust when exposed to humid environments for extended periods, but the color of the primer will hide any rust color.
Red Oxide Primer is an environmentally safe, water-based paint. Once applied to all structural steel components of a steel building, surface rust is inhibited. The primer is very durable and can take the abuse of truck loading and unloading, as well as all the handling in the field while riding. Primed steel will also withstand harsh weather before the construction of the metal building is complete. With a primer finish, you have the option of painting the steel any color to match the interior of the building if required.
In general, red oxide primed steel is the way to go for most steel construction applications. Greater flexibility, lower cost, and aesthetically superior to galvanized steel, most builders around the world choose primed steel.
