Site Maintenance Repair Coating

Client

UK Water Treatment Works

Scope of Work

Due to site impracticalities of a full coating overhaul, abrade damaged coating only (specified to WIMES 4.0 Issue 3) back to a sound edge and repair coating.

Products

High Solids, High Build Two Component Epoxy Polyamide Mastic.

Substrate

Carbon Steel

Coating System

Areas to be repaired were thoroughly degreased / abraded degreased to remove existing chalking and surface contaminants to a cleanliness standard of St3 in accordance with ISO 8501-1:2007. The Mastic Coating was applied in 3 coats to ensure a minimum dry film thickness of 275 microns in accordance with the WIMES 4.0 Issue 3 specification.

Coating Details

A self primed, surface tolerant paint system or an intermediate or finishing coat in heavy duty paint systems where low VOC and high film build are required.

Photographs

Images showing repaired areas.

Note the repaired areas are a stark contrast to the older coating, even though the same coating system is used. This is due to chalking of the existing coating. This is a common drawback of epoxy coatings that are exposed to UV light and ‘a powdery, friable layer on the surface of a coating; excessive chalking can be detrimental as it can lighten the colour of the coating, erode the coating film, resulting in a loss of protection’. This is why epoxy coatings in an external environment are generally over coated with an acrylic or polyurethane top coat which offers superior UV light protection.