Seal- ing water tanks should be done properly, with great precision and care. Any incorrectly performed application step or incorrectly selected product can lead to a leaky coating. This can result in problems with water escaping through the tank walls. 

When selecting the right materials, we should also take into account their properties and application: whether it is to be a paint that will protect a tank for drinking water or technical water , what temperatures the coating should be resistant to, whether the coating will withstand water pressure, what surface the paint will be applied to, etc.

We distinguish several product groups: 

a) paints for protecting drinking water tanks

b) paints for protecting technical water tanks

c) paints for protecting sewage/chemical tanks. 

Securing the drinking water tank

When it comes to protecting the surfaces of drinking water tanks, it's important to choose appropriate products with appropriate certifications. The basic document that approves paint coatings for use on tanks is a PZH certificate for direct contact with drinking water. Two products have this certification: Epimal 200 and RO 5500. Below is a brief description of the systems.

Epimal 200

Epimal 200 is a two-component, water-based epoxy paint. Epimal 200 can be applied to a variety of substrates: steel, wood, concrete, and tiles. The substrate must be properly prepared and primed beforehand. Epimal 200 should be applied in three coats to ensure proper tank protection (all coats should have a dry thickness of ~150 microns).

Epimal 200 is an epoxy, which is also a big plus in the case of tanks where water will be heated.

Temperature resistance: 

(permanent contact – dry environment 100°C, moist environment or immersion 40°C; temporary contact – dry environment 150°C, moist environment or immersion 80°C.) 

This paint provides a durable coating that is also largely resistant to chemical agents (diluted acids, alkalis, salts, oils, greases, fuels, solvents, detergents, etc.). 

Sanitary recommendations – food products: 

Before being put into service, tank surfaces intended for direct contact with food and feed products should be left (seasoned) for 7 days at 20°C. At lower surface and air temperatures, this time should be extended. After this time, the surface should be washed three times with water at +70°C, preferably under low pressure. Once dry, the surfaces are ready for use. Tanks can be flooded with water 14 days after the paint is applied. 

Examples of land:

  • For painting concrete surfaces, the recommended primer is Epimal G20 . Epimal 200 is an epoxy (hard) paint – therefore, it requires an epoxy primer. Applying a soft, acrylic primer will cause the coating to peel and flake.
  • When painting tiles: it is necessary to use Super Spoiwo 3333 RO2102  spray primer
  • Prime steel surfaces with Epimal Stal .
  • Previously painted surfaces – if the old paint adheres well, you can paint directly; for high-gloss paints, we recommend mattifying the surface.

RO 5500 

RO 5500 is a two-component, solvent-free epoxy paint. It's excellent as a protective coating against chlorine and is PZH-approved for direct contact with drinking water. It's resistant to oils, solvents, and many chemicals. It creates easily washable surfaces. It's a high-build epoxy—we recommend applying two coats for tanks with a total dry thickness of 200 microns. A tank protected with RO 5500 is watertight, and the coating is resistant to water pressure. RO 5500 is an epoxy, which is also a major advantage for tanks where water will be heated (the coating is resistant to constant contact with water at a maximum temperature of 50°C).

Sanitary recommendations – food products: 

Before being put into service, surfaces intended for direct contact with food products should be left (seasoned) for approximately 10 days at 20°C. At lower surface and air temperatures, this time should be extended. Once dry, the surfaces are suitable for use. Tanks can be flooded with water 14 days after the paint application (at +20°C).

Examples of land: 

  • Tiles and very smooth, non-porous concrete – RO3333
  • Porous, mineral substrates – epoxy primer Epimal G20 or RO5401
  • Fresh (minimum 2 weeks) and damp concrete – Neopox Primer WS
  • Steel – Epimal Stal
  • Non-ferrous metals – use Galvinoleum RO3202
  • Previously painted surfaces – if the old paint adheres well, you can paint directly; for high-gloss paints, we recommend mattifying the surface. 

Securing the technical water tank 

Technical water tanks, unlike the tanks mentioned above, do not require documentation. One such product is Epodux IM 209 epoxy paint. 

Epodux IM 209

Epodux IM 209 is a solvent-based epoxy paint. Why is this particular paint used in tanks? This product tolerates moisture very well. Thanks to the curing process, which occurs underwater, the item can be immersed in water just 30 minutes after painting. The cured coating is watertight, making it suitable for application to leaking tanks. The coating can be permanently immersed in freshwater and saltwater at temperatures up to +120°C (applied in two layers of 250 microns dry).

securing water tanks
epodux water tank protection

During application, consider the application times and temperatures. The minimum air temperature during application is ~10'C . The coating reaches full hardness after 24 hours at 10'C . Of course, the higher the application temperature, the shorter the hardening time. Recoating time at 10'C is at least 15 hours.

Sewage/chemical tank protection

Another type of product is a resin designed to protect tanks whose surfaces must be highly chemically resistant . One such product is Neopox CR .

Neopox CR creates a low-odor, highly chemically resistant . It performs best in areas such as tanks and other surfaces exposed to chemicals, including sodium hypochlorite and even 50% sulfuric acid (VI). A complete chemical resistance table is available in the product data sheet. It can be used in shafts, sewage tanks, water treatment plants, and water utilities.

Its extended application also stems from its ability to be applied to various substrates using system primers. It can be applied to concrete and steel substrates. To achieve a fully sealed and resistant coating, Neopox CR in two layers: depending on whether the surface to be protected will be vertical or horizontal, prepare the appropriate amount of product. Product consumption is higher for horizontal surfaces than for vertical surfaces: horizontal: 0.33-0.4 kg/m²; vertical: 0.28-0.33 kg/m².

Summary

Securing your tank doesn't have to be a problem or a hassle. Just contact us, and we're sure to find a solution. As mentioned above, we have products certified for direct contact with drinking water , solutions for demanding surfaces , and those that must be resistant to chemicals .

Having trouble drying out your concrete tank and need to renovate it? Check out our article , " How to Quickly Renovate a Damp Concrete Tank ?"