Tank Coating: How Quality is Only As Good As Application
When it comes to steel storage tanks, there is no going around the fact that the quality of coating is paramount.
Heartland Tank Services says carefully choosing the coating quality will not only increase your tank’s lifespan, but also prevent the need for premature re-coating.
The coating decision affects other essential factors, such as capacity, size, turnaround time and ease of construction. You should also factor in any special conditions specific to the application and maintenance requirements in your deliberation. But being the only tank’s defense against corrosion, which
can cause leakage, coating requires the most attention.
The coating quality, however, is only as good as its application. Here are two types of coating applications:
Field installation
Typically, tanks are sand-blasted and coated with epoxy using a handheld-sprayer, a requirement in some localities. Overspray should also be caught to avoid VOC or silica release into the air.
This type of installation often includes two applications, a primer followed by a top coat, like acrylic polyurethane. Field-applied coatings usually depend on ambient for the curing process, which can take up to 70 hours. At which time, they are subject to contamination brought by humidity, wind and dust.
Factory application
Factory-applied coatings may involve glass-to-steel fusing process. This requires molecular interaction and produces a coating that combines glass and steel, fusing them for good.
Some tank manufacturers have technology that can fuse three coats to the steel during one firing, which would otherwise take two. This not only reduces time and cost, but also minimizes the risk of contamination between coats.
Curing still depends from tank to tank. Some coatings are cured by ambient air, although a thermal cure is more commonly preferred.
Applications under factory-controlled conditions prove to be more durable and longer lasting than field installations.
Regardless of application, all tank coatings are tested for quality. Missed spots are so small they can’t be seen by the naked eye, which won’t help you detect rust and corrosion. While corrosion will not spread with glass-fused-to-steel coatings, all other types should be tested for missed spots before releasing the tank for use.
