How to Secure a Broken Fog Light Mounting Boss

Fog light mounting bosses are common in Kia and Hyundai bumpers. When one breaks, it can be hard to fix using normal methods because the plastic is so thin.
In this video, we demonstrate a repair on a fog light boss using an airless plastic welder, FiberFlex welding rods, and 2045 stainless steel wire mesh.

FiberFlex is a universal rod that sticks to nearly any plastic, but it is designed to work best on today’s popular polypropylene and TPO bumpers. FiberFlex is formulated with carbon and glass fiber reinforcement for strength and sandable filler for sandability. It does not provide a true fusion weld; instead, the FiberFlex is a hot-melt adhesive that is applied with an airless plastic welder. So, it is similar to a brazing process.

Do not attempt to weld the FiberFlex rods with the nitrogen plastic welder.

This article gives the basics on how to use Polyvance's FiberFlex universal welding rods.

Always wear proper safety gear while working!

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Click here: https://www.youtube.com/watch?v=-nzLvmgXQ24

Products Used:

Note: This is a list of the Polyvance products that can be used to make this repair. This list does not include sanders, grinders, or other common tools you will need. If you have any questions, please don't hesitate to call technical support at 800-633-3047.

• FiberFlex Welding Rod and Reinforcing Mesh (choose a method below):
• 5210 FiberFlex Repair Kit (230V kit available here). The kit includes a 5" x 10" sheet of stainless steel reinforcing mesh and 15 feet of FiberFlex welding rod.
• FiberFlex Welding Rods and 2045 Reinforcing Mesh with the airless plastic welding side of a nitrogen plastic welder or an one of our other airless plastic welders.
• 5700HT Mini-Weld Model 7 (230V kit available here). The 5700HT kit includes a 15 foot starter pack of FiberFlex and one 5" x 10" sheet of stainless steel reinforcing mesh.
• Note: Make sure you are using the 6031 flat tear drop shaped welding tip when using the flat FiberFlex rods.

Video Notes:

• This type of repair can be done with the Mini-Weld Model 7, the 5210 FiberFlex Repair Kit, or the airless side of a nitrogen plastic welder.
• English Closed Captions have been provided for this video. Click on the CC button to turn them on or off.
• The length of this video is in no way representative of the actual time required to perform a complete repair and therefore should not be used for estimating purposes.

Music Credits:

• "Super Friendly" Kevin MacLeod (incompetech.com)
  Licensed under Creative Commons: By Attribution 3.0 License
  http://creativecommons.org/licenses/by/3.0/
• "Wallpaper" Kevin MacLeod (incompetech.com)
  Licensed under Creative Commons: By Attribution 3.0 License
  http://creativecommons.org/licenses/by/3.0/

English Transcript:

Fog light mounting bosses are common in Kia and Hyundai bumpers. When one breaks, it can be hard to fix using normal methods. In this video, we will show you how to secure a broken mounting boss so it will be just as strong as before.

These Kia fog light bosses have very thin plastic on the sides. Normally we would nitrogen weld the boss back on, but this would be very difficult to do because the plastic here is so thin. So we will do the repair using an airless plastic welder and 2045 stainless steel wire mesh.

First, cut two small rectangular pieces of stainless steel mesh. They should be roughly the same size. Take a screwdriver and bend the pieces of mesh at a ninety-degree angle. Line up the mesh against the bottom of the boss. The mesh should be aligned so that the mesh is sticking out beside the boss, and not pointing toward the inside of the boss.

Use an airless welder to heat the mesh and the plastic under the mesh. Use a screwdriver or other tool to push the mesh into the melted plastic. Repeat this process on the other side. Both sides should now have mesh attached. This mesh will be used to anchor the boss into the bumper.

Sand the area where the boss will be placed to remove the paint, making sure to not sand off the position lines. Align your boss to the proper position. Use the airless welder to melt the mesh and the plastic under the mesh. Use a screwdriver to press the mesh into the melted plastic. Repeat this process on the other side.

Melt some FiberFlex rod and place it on top of the mesh. Smooth it into the bumper. Continue laying down FiberFlex until the mesh is covered. It is best to work in small sections instead of using a lot of rod at one time. Cover the mesh on the other side using the same method: just melt the FiberFlex and smooth it over the mesh into the plastic. Allow the FiberFlex to cool naturally, or force cool with compressed air. We pulled on this boss to test the strength. It's plenty strong to hold the fog light in position.

Polyvance has been focused on plastic repair and refinishing since 1981. Because of this focus, we know our products very well. When our customers use our products and repair methods, they can feel comfortable knowing they are backed by the years of experience of our plastic repair experts.

Thanks for watching, and make sure you subscribe to our channel and hit the bell to be notified when we post a new video. Let us know in the comments what you thought of this repair, and check out our other videos for more plastic repair tutorials.