In 1996, COVAC were asked to inspect the internal surfaces of a large, steel, potable water retaining structure for a major UK distillery responsible for bottling high volume whiskey brands. The internals of the structure had been coated with an epoxy. However, within a year of it being applied the ‘top’ coat (grey) was de-bonding from the ‘primer’ coat (brown). It later transpired that the two companies involved in the application of the epoxy coating (the manufacturer of the epoxy coating and the contractor who applied it) were in dispute as to whose fault it was that the failure had occurred. In short, the manufacturer was blaming the contractor citing bad workmanship, whilst the contractor was blaming the manufacturer citing faulty product.
This situation clearly emphasises what can go wrong when a separate contractor applies another companies products. We strongly believe that the market demands more than just a supplier of products and a separate contractor to undertake the project. COVAC provide a unique service to the industry which incorporates:
This turnkey service offers complete assurance to the client.
These images show the external of the water retaining structure:
These images show the de-bonding of the epoxy coating:
In addition to the ‘de-bonding’ it was also discovered that the ‘primer’ coat was not WRC (now WRAS) or DWI approved and furthermore, contained Phenol which was leaving an unacceptable taste and odour in the water (bad news for a distillery involved in the bottling of whiskey!). This meant that the job HAD to be rectified as soon as possible in order that the distillery could resume production.
Whilst the distillery had to begin legal proceedings with both the contractor and the coating manufacturer, COVAC were asked to "put the job right".
The first step was to remove all the existing epoxy coating utilising dry abrasive blasting techniques which also raised a surface profile on the substrate.
Secondly, all the sharp edges, weld joints, struts etc. Were ‘stripe coated’ in order to maintain a high volume of Solvent free Polyurethane Coating to the most susceptible areas of the structure.
We then appliedSolvent Free Polyurethane Coating by means of Hot Applied, Plural Component Spraying equipment in order to achieve a total nominal W/DFT of 1000microns (MM).
Thickness readings were taken and the completed tank fully inspected.
On completion of the project COVAC submitted the distillery with a COVAC Completion Report (including photographs taken of strategic stages of the project) and a Ten Year Guarantee.
In 2007, the distillery contacted COVAC as they had realised that over ten years had passed and the structure was now out of its guarantee period. Although the distillery had inspected the structure themselves and found it to be ‘faultless’ we were asked if we would be prepared to inspect the structure ourselves and offer an additional Ten Year Guarantee.
We inspected the structure thoroughly in late 2007 and the structure now has an extended guarantee, offering the distillery complete peace of mind until 2018.
This image shows the internals of the structure in our 2007 inspection, 11 years after they were initially relined by ourselves.