Rust in Cast Iron Drinking Water Storage Tank

Question:

During our annual tank cleaning and inspection, we found severe rust damage to our cast iron water storage tanks. Our problem has been finding a primer and paint product that is approved for drinking water storage tanks. Any advice on known paints or other products would be greatly appreciated. C. A.

Answer:

Since it is against the policy of the Painting Clinic, I cannot recommend specific paints and primers to be used in finish systems or linings for potable water tanks. These finish systems and tank linings must meet standards of the Food and Drug Administration (FDA), Environmental Protection Agency (EPA), Occupational Safety and Health Administration (OHSA), National Public Health Service and other regulatory bodies. Although the American Water Works Association is a good source for finish systems and linings for potable water tanks, Paint suppliers listed under Chemical Coatings in the 2005 Products Finishing Directory and Technology Guide (www.pfonline.com/suppliers.html) should be able to provide primers and topcoats for your cast iron water storage tanks.