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 can we seal a concrete tank that we can't completely dry out or that has a very short timeframe? We present a quick and effective solution. The selection of materials for sealing damp tank walls plays a key role in achieving a durable and airtight seal.

Below we present one of the proven systems that allows us to apply products to damp surfaces and also enables quick refilling of the tank with water. 

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

The system proposed below allows for high moisture content in the concrete substrate . Before applying the primer, the substrate must be properly prepared. It's best to grind the concrete to remove surface contaminants. After thoroughly dusting the substrate , apply the primer.

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

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

A primer that can be applied to damp concrete is Neopox Primer WS . This is a solvent-free epoxy primer , most often used on substrates where moisture is caused by, for example, sudden rainfall, pressure washing, or, in the case of tanks, by previous filling with water. High concrete moisture is not the same as standing water or a puddle (excess water from the substrate must be removed immediately!) .

Primer is usually applied in a single layer. The concrete should have a uniform gloss after application. If matte spots are observed after 24 hours, this indicates that the substrate is highly absorbent and should be re-primed. The permissible substrate moisture content is 100% . The topcoat can be applied 24 hours after applying the primer.

Topcoat application

Epodux IM 209 epoxy paint as a topcoat for closed tanks . Why Epodux IM 209 be used in jobs that require a short time? Because Epodux IM 209 allows for very rapid contact with water. Standard epoxy resins require between 7 and 14 days before being immersed in water, whereas elements painted with Epodux IM 209 can be immersed in water after just 30 minutes ! However, we recommend caution against contact with a strong water jet after such a short time.

Epodux IM 209 is an excellent 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 has the appropriate thickness, and therefore is 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 200 microns dry (total 400 microns dry)

When spraying, the paint can be applied thickly in a single coat, but we don't recommend this when painting a tank. To ensure a tight and durable coating, we recommend applying two coats, applied crosswise.