As a result of poor coating application practice the existing epoxy bund lining had failed prematurely. The previous contractor had failed to fill the numerous blow holes in the cast concrete substrate, allowing water/moisture to penetrate causing the resultant failure. The extremely poor adhesion between the existing top coat and primer in the bund suggested that the overcoat window between the coats had been exceeded.
Due to the extremely poor adhesion of the existing coating system it was necessary to achieve a high standard of surface preparation. The bund was prepared throughout by method of abrasive blasting to remove all loose and unsound coatings present as well as raising an excellent surface profile throughout the bund for optimum coating adhesion.
Once satisfied with the standard of surface preparation the first stage of the bund lining process was to prime throughout the bund with Remmers Epoxy MT – a high quality moisture tolerant epoxy primer. Pigmented quartz aggregate was broadcast into the uncured epoxy primer to act as a barrier between the incompatible coatings systems.
The next stage of the bund lining process was to apply throughout the bund a coat of glass flake reinforced vinyl ester coating to a dry film thickness of 500 microns. Once cured the entire bund was inspected for blow holes. Any found were marked prior to being filled with a twin component polyester filler. A second coat was then applied throughout the bund to an overall system thickness of 1000 microns, giving a seamless highly chemical resistant bund lining. Vinyl ester resins offer some of the highest levels of chemical resistance available, with outstanding abrasion resistance properties as well.