Repairing a Tear on the Corner of a Bumper

In this video, we’ll be focusing on one of the most commonly damaged areas of a plastic bumper. The corner of a bumper is fairly weak and can sustain damage even if it’s not directly impacted in a collision. A collision repair technician can repair this type of damage and restore the bumper to like-new condition using products and equipment from Polyvance.

For this demonstration, we’ll be using a polypropylene bumper with an L-shaped crack that runs along a body line. We’ll repair the crack using Polyvance’s polypropylene welding rod and a nitrogen plastic welder and refinish the bumper using flexible filler and waterborne primer. Using the techniques shown in this video, a collision repair technician can repair this type of damage on most plastic bumpers.

Always wear proper safety gear while working!

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Click here: https://www.youtube.com/watch?v=FO1_Y5jXnKo

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.

• 1000 Super Prep Plastic Cleaner (several options available) OR 1001-4 EcoPrep Plastic Cleaner
• 6204 Hot Spot Plastic Stapler
• Aluminum Body Tape (several options available)
• 6122 Heavy Duty Round Cutting Burr
• 6125 Tapered Burr
• Polypropylene welding rods
  Note: We used polypropylene here because of the identification symbol. Choose the rod that matches the plastic you need for your repair.
• For this repair, we used R02-04-03-NT and R02-05-03-NT on the back and R02-01-03-NT on the front.
• Nitrogen Plastic Welder (several options available)
• Plastic Magic Adhesion Promoter (several options available)
• 2000-T Flex Filler
• Waterborne Primer (several options available)
• We used 3043 Black Jack

Video Notes:

• 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:

• "Sage" by Slenderbeats
  From the YouTube Audio Library

English Transcript:

In this video, we’ll be focusing on one of the most commonly damaged areas of a plastic bumper. The corner of a bumper is fairly weak and can sustain damage even if it’s not directly impacted in a collision. A collision repair technician can repair this type of damage and restore the bumper to like-new condition using products and equipment from Polyvance.

For this demonstration, we’ll be using a polypropylene bumper with an L-shaped crack that runs along a body line. We’ll repair the crack using Polyvance’s polypropylene welding rod and a nitrogen plastic welder and refinish the bumper using flexible filler and waterborne primer.

First, clean the plastic thoroughly with plastic cleaner. Contamination in the repair area can cause a weld to fail, so it’s important to remove any dirt, grease, or grime. Next, align the plastic and use hot staples and aluminum tape to prevent the crack from separating. To prepare the area for welding, grind a shallow v-groove along the center of the crack. Be sure to grind away an even amount of plastic on both sides of the crack. At the edge of the bumper, grind at least an inch to an inch and a half on both sides of the crack.

To begin the weld, preheat the welding rod and the bumper. Touch the welding rod to the bumper and apply steady downward pressure, making sure both plastics are melted evenly. Weld all the way to the edge of the bumper before breaking off the welding rod. To reinforce the repair, melt a strip of welding rod into the v-groove along the edge of the bumper. Use the airless plastic welder to smooth and shape the weld. Allow the plastic to cool to room temperature.

Once the plastic has cooled, remove the aluminum tape and the hot staples from the front side. Apply a piece of aluminum tape over the weld on the back side. Make a deep v-groove along the crack, grinding about halfway into the plastic. Make sure the crack is center of the v-groove. Apply at least two passes of welding rod to fill in the v-groove. Use the airless welder along with the nitrogen welder to smooth and shape the weld. Again, allow the plastic to cool to room temperature.

After the plastic is completely cool, remove the aluminum tape from the back side. Sand the weld, starting with 80 grit and finishing with 180 to 320 grit. Blow off the repair area to remove any sanding dust. Apply one to two light coats of adhesion promoter, allowing flash time in between coats. Once the adhesion promoter has flashed off, apply a flexible filler over the repair. Allow the filler to cure, then sand and block with 80 grit, finishing with 180 to 320 grit. Apply another one to two light coats of adhesion promoter and allow to flash off. Spray one to two coats of primer-surfacer and allow to dry. Block, sand, and re-prime as needed to achieve desired appearance.

Using the techniques shown in this video, a collision repair technician can repair this type of damage on most plastic bumpers.