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
Grit blast to ISO 8501-1 cleanliness std SA 3
Polyglass VEF applied at 1000μm DFT
Polyglass 100 Zipcoat applied at 1000μm DFT
Plasmet HTE applied at 2000μm DFT
Plasmet ZF applied at 400μm DFT
Access to the gates is 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 have revealed that whilst further deterioration of the epoxy resin / coal tar epoxy coated gates is 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.
The spillway gates at Glenmaggie and access to the gates was the first hurdle for Corrocoat
One of the spillway gates after coating – note the complex geometries
Visual inspection of one of the gates after service – showing no coating breakdown.
Rebuilding and protecting severely worn sludge rollers to original dimensions.
Plasmet T and glass fibre reinforcing fabric
Fabricated steel rollers
Pre-machine to get back to good surface. Grit blasted to ISO 8501-1 cleanliness standard SA 2 1/2. Plasmet T applied with 100mm wide glass fabric reinforcement. Post machine to final drum sizes.
Plasmet T is a high solids epoxy coating loaded with Silicon Carbide to provide added abrasion resistance. Plasmet T, when coupled with glass fibre reinforcing, as in this application, builds strength and thickness to these worn sludge rollers. The specification of these drums also utilised Plasmet T’s ability to be machined and ground to a very smooth finish. Designed primarily as a cosmetic top coat for Plasmet R and WR, Plasmet T provides excellent chemical resistance and a good gloss appearance. Using coating as a method of refurbishment has proved cost and time effective on these sludge rollers. Traditional methods of welding and machining have a turn around time of weeks, and replacement is expensive. Corrocoat’s solution can be turned around in days and is around
half the cost of a new roller. An additional benefit with the refurbishment option is that, with the enhanced properties of Plasmet T, the life of the component will now be greater than that of a new roller – adding to the cost benefits of using Corrocoat coating systems.
Rollers on arrival into our works
The roller is pre-machined, and grit blasted before the application process begins
The post-machined roller ready for packing and despatch