There are an unlimited number of brands and types of Shop Coat Primer for the Steel Fabricator to choose from. Levels of quality vary greatly and different systems can be called out on shop drawings. They will range from the basic Red Oxide or Gray shop coat, with no additional requirements to the more complex and much more expensive 2-part systems, High Solids Rust Inhibitives and Universal Primers.

Fabricated steel is usually primed in the shop and at times requires welding in the field. Most alkyd (oil) based primers will burn away immediately and turn to dust. This leaves the weld and weld area without any corrosion protection. Often, it will begin rusting within days. There are a number of factors that cause weld material to rust. For a better understanding of what causes Weldment Corrosion ASM offers an in-depth review “Basic Understanding of Weld Corrosion.” (click)