How to quickly renovate a wet concrete tank?

Over time, concrete tanks lose their tightness. This happens because concrete loses its compactness and impermeability over the years. We only start to react when we observe, for example, a lower water level in the tank, which indicates problems with tightness.  

How to seal a concrete tank that cannot be completely dried or the time to secure it is very short? We present a quick and effective solution. The selection of materials to protect wet tank walls plays a key role in obtaining a durable and tight coating.

Below we present one of the proven systems that allows us to apply products to a damp surface and also allows us to quickly fill the tank with water again. 

How to prepare the substrate before securing/sealing a damp concrete tank?

The system proposed below allows for high humidity of the concrete substrate . Before applying the primer, the substrate must be properly prepared. It is best to grind the concrete to remove surface contamination. After thoroughly removing dust from the substrate, we begin applying the primer.

How to prime the substrate before securing/sealing a damp concrete tank?

After appropriate preparation of the surface, you can start the long process of drying the concrete or choose a special primer that allows you to speed up the work and skip this stage.

The primer that can be applied to damp concrete is Neopox Primer WS . It is a solvent-free epoxy primer , most often used on substrates where moisture results from, for example, sudden rainfall, washing with water under pressure, or, as in the case of tanks, from previously filling with water. High humidity of concrete is not the same as standing water or puddles (excess water from the substrate must be removed!) .

The primer is usually applied in one layer. After applying the primer, the concrete must have a uniform shine. If dull spots are observed after 24 hours, it means that the absorbency of the substrate is high and priming should be repeated. Permissible substrate moisture is 100% . After 24 hours after applying the primer, you can start applying the topcoat.

Topcoat application

Epodux IM 209 epoxy paint as a topcoat for a closed tank . Why Epodux IM 209 be used in jobs that require a short time? Because the Epodux IM 209 allows for very quick contact with water. Standard epoxy resins need between 7 and 14 days before being poured with water, while elements painted with Epodux IM 209 can be immersed in water after just 30 minutes ! However, we recommend that you be careful about possible contact of the coating with a strong stream of water after such a short time.

Epodux IM 209 is a very good product not only for sealing tanks but also for painting steel structures that will be immersed in water. The product can also be used in aggressive environments such as sewage treatment plants .

When painting the tank with Epodux IM 209 paint , make sure that the dry coating is appropriately thick and therefore tight and resistant to water pressure.

Depending on the design, the following coating thicknesses are assumed:

• clean technical water – two layers, each 100 microns dry (total 200 microns dry)
• water contaminated with chemicals, sewage - two layers, each of 200 microns dry (total 400 microns dry)

In the case of spray application, the paint can be applied thickly in one layer, but we do not recommend this when painting the tank. To ensure that the coating is tight and durable, we recommend spreading the application into two layers, applied crosswise to each other.