Sectional Steel Water Tanks Case Study 445

These images show a large sectional steel tank before any preparation work and then after preparation. The large sectional steel tank was fully relined with Acothane DW.

A lining system was required for a newly constructed sectional steel effluent tank located at a cheese factory in the South West. The large sectional storage tank is sized at approximately 33m x 2.4m x 3.6m (with no roof) and sited externally at ground level.
From initial installation the tank had been leaking at its horizontal joints & had recently been coated with chlorinated rubber inside & out.

Problem with the Sectional water tank

The client needed the tank to be operational as quickly as possible with all leaks sealed and required a durable coating that capable of withstanding chemical attack from the factory effluent with a minimum 10 year life expectancy. After looking at several options Acothane DW was specified for the following reasons:

  • Fast curing time so the storage tank could be operational as soon as possible
  • Proven life expectancy of over 10 years
  • Excellent chemical resistance
  • Flexible with excellent elongation properties
  • Tough – high impact and abrasion resistance
  • Solvent Free Polyurethane
  • Easy to clean making future maintenance simple
  • Exceptional track record

A suitable sub-contractor was chosen to prepare the tank and apply the Acothane DW coating. The sectional steel tank was prepared using grit blasting equipment to provide a suitable surface profile to promote optimum adhesion of Acothane DW. After blast cleaning all dust, residues and debris left on the surfaces was completely removed.

All exposed & protruding rubber jointing strip was cut back until flush with the steel substrate. All joints were then filled with Acothane Mastic Grade that is specifically designed for application by trowel, stiff brush or spatula and is completely compatible with Acothane DW.

Acothane DW was then be applied by plural component hot airless spray equipment to provide a tough, flexible seamless finish. All crevices and deeply pitted surfaces were completely penetrated and coated particularly edges, bolt heads, weld runs, etc. During application the operatives carried out regular checks of wet thickness with a wet film thickness gauge to ensure the specified thickness was applied.

As this is an effluent tank and not subject to DWI regulations the Acothane DW coating only needed to cure for 24 hours before the tank was ready for use.