Case Study

Corrosion Protection for Spillway Gates


Water industry, Australia.


Application date

1995 & 2004.


Scope of work

Replace original coal tar epoxy coating.



Upstream submerged areas: Polyglass VEF.
Downstream submerged areas: Polyglass Zipcoat.
Rubbing areas: Plasmet HTE.
Normal atmospheric exposure areas: Plasmet ZF.



Mild steel & cast iron fabrication.


Coating System

• Access to the gates was difficult and expensive, being 80 metres above the river bed, so long term corrosion protection is highly desirable for this asset with a required life of 200 years.

• Despite the use of established coatings and reputable painting contractors, early coating breakdown was recorded in the first couple of years of the gate re-painting program.

• Corrocoat Engineering Victoria, offered a 10 year warranty with an expected life of 30 years.

• In 1995, Corrocoat was requested to refurbish three gates as a result of a life cycle cost-benefit comparison exercise, between a combination of Corrocoat systems and other lower cost epoxy resin systems. Corrocoat was awarded the work for 3 gates, and it was carried out successfully, in the middle of winter, with the gates being put back into operation on time.

• Inspections in 2004 revealed that whilst further deterioration of the epoxy resin / coal tar epoxy coated gates was evident, no such deterioration of the three gates coated using Corrocoat’s system was noted by the delighted customer, with the equipment remaining in excellent condition.



Access to the gates was the first hurdle for Corrocoat - One of the Spillway Gates following coating (note the complex geometries - Visual inspection of one of the gates after service - showing no coating breakdown

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