Echo Square Services Ltd were asked to provide a solution to refurbish four GRP cold water storage tanks which were suffering from deterioration of the internal gel coat and corrosion of steel fittings.
We proposed that each tank be given long term protection by the application of a solvent free polyurethane coating.
The product employed was a solvent free DRINKING WATER POLYURETHANE (DWPU), which offers numerous economic, technical and environmental features and benefits, some of which are highlighted below:
- WRAS Approved
- Complete Solvent Free Technology
- High degree of flexibility @ > 35%, capable of accommodating structural movement compared with resin / epoxy / bitumastic coatings of <1.0%
- Superb adhesion to steel, concrete, GRP and many other substrates.
- High levels of impact and chemical resistance.
- Long life performance with minimal maintenance
- Easy clean, ceramic tile-like finish
- Excellent track record for applications such as drinking water tanks, cooling towers, reservoirs etc.
Methodology
TANK 1
BEFORE – The tank internal surfaces were in very poor condition and there were signs of previous repairs.
PREPARATION – The tank internal surfaces were manually prepared to create a 75um surface profile to accept the DWPU coating.
REPAIR – Where the previous GRP repairs had started to delaminate, fiberglass repairs were completed to seal these gaps and holes in the hollow tie bars.
BASE COAT – A base coat of DWPU was applied to all internal surfaces at a nominal thickness of 500 micron.
TOP COAT – The above was repeated with a top coat of DWPU.
TANK 2
The above was repeated for the second tank
TANK 3
The above was repeated for the third tank
TANK 4
The above was repeated for the fourth tank
