Damaged wind turbine blades repaired with Belzona 5711 and Belzona 5721
The recently launched Belzona 5711 was put straight to the test on several damaged wind turbine blades at a wind farm in Thailand owned and operated by a leading energy company. The blades were suffering from lightning strike damage and pitting to the leading edges, while the tips of some blades had received impact damage from bird strikes.
Belzona distributor for Thailand, Pan Mechanic Engineering (PME), was contacted by the energy company to provide a cost-effective repair solution for the damaged blades. Engineers from PME recommended a system comprising of the new Belzona 5711 and the now well established Belzona 5721.
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Belzona 5711 is a high-performance, easy to apply system specially designed to repair erosion and impact damage on the leading edges of wind turbine blades. It is supplied in a cartridge format, making it easy to apply and ideally suited for applicators using rope access. Belzona 5711 cures quickly and can be directly overcoated with Belzona 5721 in 30 minutes at 20°C/68°F, without the need for any additional preparation.
The most efficient way to repair the blades was via rope access; with this in mind, PME selected a certified rope access contractor to carry out the repair and protection application for the damaged blades. As Belzona 5711 is a brand new product, application training to both PME and their contractor was provided at the Belzona Asia Pacific Training Centre in Laem Chabang, Thailand.
The one-day course started with a theory session on Belzona 5711 and Belzona 5721, followed by a blade surface preparation demonstration in the workshop. Engineers and contractors then received practical training on the use of battery-powered orbital sanders on a real wind turbine blade.
The training continued with a demonstration and practical session on effectively rebuilding surfaces and repairing pitting on damaged turbine blades with Belzona 5711. The course concluded with a training session on the correct overcoating procedures when using Belzona 5721 in conjunction with Belzona 5711.
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Belzona 5721 is a 2-component, high-performance coating that protects the leading edge of wind turbine blades from erosion and impact damage. This system is ideally suited for the rigours of in situ applications, being easy to apply by brush in a single coat. In addition, with its low-temperature cure technology, Belzona 5721 can maximise available maintenance opportunities and ensure the turbine’s fast return to service.
As this was the first-ever application of Belzona 5711 in Thailand, representatives from all parties concerned were in attendance at the wind farm. The three-person application team consisted of two applicators using rope access and one spotter on the ground. The application process began with cleaning the damaged blades with a mix of water and degreaser, and the affected areas were identified and marked out. Next, the damaged surfaces were sanded down with 80 grit sandpaper, and Belzona 5711 was applied to repair and rebuild each of the damaged blade’s surfaces and leading edges.
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Once the Belzona 5711 application had cured, the applicators used masking tape to mark out the areas for overcoating with Belzona 5721. To complete the repairs, Belzona 5721 was applied within the Belzona 5711 overcoating window. After the Belzona 5721 had cured, the masking tape was removed, and the wind turbines were ready to return to service and protected against leading edge erosion for the long term.
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A representative for the energy provider said:
“The speed and efficiency of the repairs carried out allowed us to minimise the downtime of our wind turbines significantly. The combination of these Belzona products appears to be the perfect choice for repairs of this kind, and we will look to use them again on future repair projects. We want to thank Pan Mechanic Engineering, their contractor, and of course Belzona for their support on this project.”
