The biggest concern of water storage tank engineers and owners alike is preventing corrosion, which can shorten the life of these extremely expensive components.

In the first part of this article series, the causes of corrosion to water storage tanks and how to best prevent it were discussed.

This continuation looks at the coating systems that tank engineers and tank maintenance services now have available to them for addressing corrosion and keeping water tanks in service longer while also adhering to recent, stricter environmental regulations.

Advancements In Potable Water Storage Tank Coating Systems

As water storage tank engineers have continuously worked to analyze how corrosion happens and what must be done to prevent it, more restrictions on VOCs and their environmental impact have gone into place at the same time.

This has presented a whole other aspect to the challenges of protecting potable water tanks.

Fortunately, this has now led to the development of storage tank coatings that are not only safer for the environment but more effective in stopping costly corrosion.

Many of the new non-solvent coatings are not only environmentally friendly but also easier to apply and more adherent when used under the right conditions.

Interior Immersion Coatings

Meeting the effectiveness and safety requirements with effective interior immersion coatings has been especially challenging for water tank services.

While there are two immersion coatings that stand up to the test - vinyls and high-solids epoxies - only the epoxies satisfy VOC regulations.

High-solids epoxy coating systems have now become the focus of tank and coating engineers with the majority of tanks using these products for interior corrosion protection when storing potable water.

With lower-viscosity and molecular weights, these coatings flow more easily, making them easier to apply and allowing them to adhere more completely to the metal.

This is important for water storage tanks with cathode protection, which can cause blistering in the coating if not carefully monitored.

High-solids epoxies work especially well with cathode protection due to the coatings having fewer voids and pinholes that could allow blistering to occur.

Exterior Coatings

There are a number of exterior coating systems in use today, with tank engineers making strides in the development of environmentally-safe products in a variety of types for use in many different outdoor conditions:

  • Direct-To-Metal Acrylics - DTM acrylic polymers are easy to apply, have superior UV resistance, and remain flexible. Available as primers and topcoats, DTM acrylics are affordable and attractive, making them a top choice by production and maintenance water tank services.
  • High-Solids Epoxy Mastics - Epoxy mastics are especially resistant to salts, acids, moisture, and chemicals, so they are appropriate for harsher conditions. They are easily applied and adhere well over old coatings in poor condition and can seal in toxic, lead-based coatings. Epoxy mastics are also frequently used as primer coatings to help other top coatings adhere better.
  • Waterborne Epoxies - Moisture, acid, and alkali-resistant waterborne epoxies are the durable, water-based, environmentally-friendly version of standard solvent-based coatings for water storage tanks. They dry quickly and form dense film coatings over metal that can withstand abrasions and reduce flash rusting when mixed with sodium nitrate.
  • High-Solids Polyurethanes - The most frequently-used coating, low-viscosity high-solids polyurethanes have replaced lead-based and high-VOC coatings as they are available in multiple formulas that resist against a wide variety of environmental conditions while maintaining a good appearance.

Prevent Corrosion With Safe and Effective New Coatings

The development of appropriate water storage tank coatings to prevent and control corrosion is a critical part of the tank design and production industry.

Tank and coating engineers continue to develop better, more versatile coatings that not only counteract the causes of corrosion but now do it in more environmentally-friendly ways.

Discuss tank coatings and how to best protect water tanks in any location with an experienced water tank service that is up-to-date on the latest corrosion-prevention coatings and methods.

Need New Water Storage Tank Coatings in Oklahoma, Texas, or Surrounding Areas?

Talk To Dunham Engineering About Water Storage Tank Services!

Call 979-413-4687 For More Info!


Part 1: Potable Water Storage Tanks - Corrosion Causes and Prevention!