After looking at the tank on ways to deal with it, the first instance would be to grit blast the current epoxy. This would effectively remove all rust and provide a profile of SA 2.5 for a new coating system. Selecting the correct coating system was of the highest importance. Firstly it would need to have certification for use in potable drinking water tanks. And of course, have the resistance to water to prevent any future corrosion.
The specified system was Jotun TankGuard DW at 400 microns dry film thickness. Grit blasting in a confined space such as drinking water tank requires skill and good teamwork. It’s dusty and visibility can be very difficult, usually due to location. It is not always possible to have the exhaust outside. On this occasion, fresh air was pumped into the confined space to help aid visibility. Removal of the coating was tough going but it is essential to remove all old coatings and corrosion from the storage tank to achieve SA 2.5. This is essential for the new coating to adhere to.
Once blasted, the spent abrasive was removed, and the tank was completely vacuumed to remove all dust. The tank was made a clean area, with all operatives having to wear new overalls, overshoes and latex gloves. This is important to stop cross contamination for the new drinking water tank epoxy coating.
