1. Application and surface preparation

Whatever tank lining you select it is vital it is applied properly. If the application or surface preparation is faulty, no matter what coating you have, it will not perform as designed and likely not meet the expected performance.

2. Empty tank

This may seem obvious but the tank must be completely emptied of product and gas in order to make it safe to carry out the application. This includes ensuring that the atmosphere in the tank is breathable, as CO2 and other noxious gasses can quickly build to lethal concentrations inside the confined space of a tank. Having a good plan for emptying the tank and ventilating it is crucial to ensure the safety of your workers. This process is very important and carries a high risk, as failure to carry it out correctly could ultimately result in death, it is critical that all procedures should be carried out correctly.

3. Blasting and cleaning

From a tank lining perspective, this is one of the most critical steps of the process. It is vital to ensure no dirt, foreign bodies, remnants of the previous coating or previous contents remain on the internal tank walls when the new lining is applied.

To carry out the cleaning, the team will stage up inside the tank and blast the internal walls to remove all waste.

After blasting and before the coating is started, it is critical to thoroughly vacuum and clean the tank to remove any particles dislodged during the process.

Using dehumidification equipment, DH, is a very efficient way of holding the blast of the tank. While it might be considered an additional expense, it is well worth considering to ensure the best final result when it comes to lining integrity and tank performance.

4. Lining

Once the blasting and cleaning are complete, it is time to start lining the tank.

The first section the applicators will work on is the walls, using the staging already erected for the cleaning process. Once complete, the staging will be removed and the floor will be blasted and coated, with the applicators working their way out of the tank. This is the most commonly used approach to lining a tank.

If your applicators are experienced, they can complete the floor while the walls are still drying, which gives you a tank that is well coated and back into service faster than if you have to wait for the walls to dry.

When coating the tank, it is important to have good ventilation and air flow. For solvent-based tank linings, the solvent evaporates during the curing process. If there is insufficient ventilation during the curing, the solvent will be unable to evaporate, and this can compromise the final quality of your tank lining.

5. Faster back to service

We know that every second counts during any shutdown, whether it’s planned or unplanned, so it’s critical to get your tanks back into service as quickly as possible.

The challenge with a lot of coatings is that after the first coat, the drying time can be up to three days before you can safely apply the second coat.

If your shut down is costing up to $12 million every day, this is an unacceptable timescale.

Wet-on-wet application can help with this. If you are coating your tank with a truly solvent free tank lining, you can have two applicators working in synchronisation inside the tank.

As the first applicator is working through the tank applying the first coat, the second applicator can follow 20 - 30 minutes behind, applying the second coat. Once the walls are coated, you can apply the floor at the necessary wet film thickness (WFT) since there is no risk of sagging, and then your coating job is done. By using this method, you receive the safety of a two-coat system – avoiding holidays, pinholes and low dry film thickness (DFT) – with the speed of a one-coat application.

Things to keep in mind when doing wet-on-wet application is to use a truly solvent free tank lining, and to ensure that your fastest applicator goes into the tank first to ensure the second applicator is not waiting on the first.

Tankguard SF, Jotun’s solvent free tank lining, can be applied wet-on-wet and allows you to return back to service faster, without compromising on chemical resistance.