How to Create a Leading Edge Protection (LEP) with Belzona

 In Belzona Educates, How To Series

Introduction to Leading Edge Repair and Protection

Protection of the leading edge of a wind turbine blade has been one of the most talked about topics when it comes to wind turbine maintenance. The leading edge is responsible for the blade’s aerodynamic efficiency and power output. For this reason, the leading edge protection (LEP) gets the most attention nowadays.

In one of our previous posts “Maintaining Renewable Energy”, we touch upon the maintenance issues encountered in the wind power turbine as a whole, and the solutions Belzona offers for the repair and protection of each part of the turbine. In this post, our focus is the leading edge protection.

What is a leading edge?

The leading edge of a blade is the foremost edge of the airfoil or the part of the blade that first contacts air.

Leading Edge Wear and Tear

Cause of the leading edge damage can vary based on the terrain a wind farm is located in. Typically, leading edge defects can be caused by wet (rain, sleet, hail, snow) and/or dry (dust, abrasive air, bugs) atmospheric and environmental particulates. Lightning strikes and surface icing are two other atmospheric phenomena that might cause tear and, in some extreme cases, even rupture in the blade.  The life expectancy of an unprotected leading edge at the manufacturer’s facility can be significantly decreased. According to www.windsystemsmag.com, eroded leading edges will reduce the aerodynamic efficiency of the blades, and many sites have measured decreased power production by as much as 12%.

Leading Edge Repair and Protection

In recent years, more blade manufacturers have started offering various type of LEP including tapes and protective coatings. However, that is not the global trend.  Many wind farms currently in operation face the challenge of protecting the damaged blades and keeping the turbines running and producing energy.

Belzona How-To

The solutions offered by Belzona are suitable to be applied on new build equipment as a preventative measure, as well as to repair and protect damaged equipment already in operation. In this post, we demonstrate the repair of a blade that had been damaged in service.

Drawing: Leading Edge Repair and Protection

In this video, we demonstrate how to repair a leading edge and how to protect it from future environmental impact. The edge of this blade had been weathered down and first required to be rebuilt to the original profile. Once the edge was restored, a protective coating was applied.

For this repair, we used  Belzona 1121 (Super XL-Metal)Belzona 1341 (Supermetalglide), Belzona 9111 (Cleaner/Degreaser), pre-formed molds, and a few tools from our machine shop. We started the application by preparing the surface. Using a handheld sander, we removed the existing coating and all loose particles. With an MBX bristle blaster we prepared the surface profile for optimal adhesion of the repair composite. Belzona 1121 was then mixed according to the Instructions for Use and applied onto the repair area with a brush. The mixed material was well embedded into the surface to ensure good adhesion. Pre-formed molds of different sizes were used to remove excess product and to smooth out the surface, following the natural curvature of the blade. Once the composite material became stable, Belzona 1341 was brush applied as a protective top coating.

Video: How to Create a Leading Edge Protection with Belzona 1341

timeline_pre_loader
PHASE I: SURFACE PREPARATION

Step 1: Clean the repair area

Sand down the repair area to remove previous coating and all loose particles.

Step 2: Prepare profile

 

 

Using an MBX bristle blaster, prepare the optimal profile.

Step 3: Remove dust

Brush off any remaining dust from the repair area.

Step 4: Degrease repair area

Using Belzona 9111 (Cleaner/Degreaser), degrease the entire repair area to remove all remaining surface contaminants.

Phase II: Edge Repair with Belzona 1121

Step 1: Mix Belzona 1121

Mix Belzona 1121 Base and Solidifier until a homogeneous color is achieved.

Step 2: Apply Belzona 1121

Using a short-bristled brush, apply Belzona 1121 and firmly embed into the surface.

Step 3: Create a smooth finish

Using a Belzona applicator, apply the remaining material to create a smooth finish.

Step 4: Remove excess

Using a pre-formed mold, remove the excess product and create a smooth finish.

Step 5: Smooth out

Using a smaller pre-formed mold, create a smooth finish by following the contour of the edge.

Phase III: Edge Protection with Belzona 1341

Step 1: Mix Belzona 1341

Thoroughly mix Belzona 1341 Base and Solidifier.

Step 2: Apply Belzona 1341

Using a brush, coat the entire repair area of the leading edge with Belzona 1341.

Step 3: Measure thickness

With a wet film thickness gauge, measure the thickness, which should not exceed 10 mils per coat.

Step 4: Remove tape

Comments
  • Ole Grünfeld
    Reply

    Dear Yulia. I have studied your article with great interest. R&D A/S, Denmark has developed and delivered 6 Rain Erosion Tester to major blade supplyer and Coating companies. We are interested to start a dialog with your company. Please let me know who to contact in your organization.
    Thanks in advance.
    Ole

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