The American Water Works Association publishes the D102-06 standard “Coating Steel Water Storage Tanks“. Specifiers use it to dictate the kind of paint coating system they want applied to their water tank. Within the D102-06 standard, there are currently 6 coating systems for exterior surfaces (Outside Coating Systems – OCS) and 5 coating systems for interior surfaces (Inside Coating Systems – ICS).
One of the interior systems can present you with several benefits if you decide to use it: ICS No. 4. It consists of a 100% solids polyurethane and/or polyurea type coating. A 100% solids coating is one that has no solvent … so 100% of what’s “in the can” is the coating, not the coating and solvent. Having a coating without solvent often allows a project to be painted more quickly because the painting contractors – and you – know that the film thickness applied is the film thickness you’ll get when the coating cures.
And 100% solids polyurea coatings, for example, cure FAST. Depending upon the particular manufacturer you choose, it could be 30 seconds to 3 minutes! No more “waiting for paint to dry”!
What’s more, these coatings are applied at a minimum dry film thickness (DFT) of 25 mils … generally closer to 40 mils. To compare this amount with other AWWA ICS, the 3-coat epoxy system (ICS No. 2) requires only a minimum of 12.0 mils, since these films are thicker and they last longer. Plus, they remain flexible and abrasion resistant if you live in a northern state where winter may cause ice to form in the tank interior.
These coatings can also be used to repair bolted tank and concrete tank interiors.