Repairing Large Holes in Bumper Covers

Large holes in bumper covers are a very common type of damage that may seem a little intimidating due to the amount of plastic that has to fabricated. In reality, a repair such as this very similar in execution to the repair of a tear or crack with a nitrogen plastic welder.

Always wear proper safety gear while working!

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
• 6125 Tapered Burr
• Aluminum Body Tape (several options available)
• Nitrogen Plastic Welder (several options available)
• 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.
• Plastic Magic Adhesion Promoter (several options available)
• 2020-T SMC Hardset Filler (Tube Kit)
• Waterborne Primer Surfacer (several options available)

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.

English Transcript:

The length of this video is in no way indicative of the amount of time it takes to perform this procedure. It should therefore not be used for estimating purposes.

Large holes in bumper covers are a very common type of damage that may seem a little intimidating due to the amount of plastic that has to be fabricated. In reality, a repair such as this is very similar in execution to the repair of a tear or crack with the nitrogen welder.

Begin by cleaning the repair area with Polyvance’s 1001-4 EcoPrep plastic cleaner. Grind down to the plastic around the perimeter of the hole, beveling slightly with Polyvance’s 6125 tapered burr. Apply aluminum tape to the front side, as we'll be starting this repair on the back. As you had done on the front, grind down around the perimeter of the hole, beveling slightly.

Using a wide polypropylene ribbon and a nitrogen welder, weld a pass of plastic, starting at the edge of the hole to lock down the welding rod onto the bumper. Overlap the ribbon over the previously laid ribbon until the hole is covered. You'll weld the other side in the same way. While the weld is still hot, smooth it using the airless and nitrogen plastic welders simultaneously. Add more layers of plastic to increase the thickness as you see necessary.

Once the weld on the backside cools, remove the aluminum tape. V-groove around the newly welded plastic, and then sand using 80 grit sandpaper on a DA sander to feather back the paint around the hole. Using wide polypropylene ribbon and a nitrogen welder, you can now weld the front side just as you had on the back, and then smooth. Once it cools, sand first with 80 grit sandpaper on a DA sander. Finish sand with 180 grit to prepare for primer. At this point in the process, we found a low spot in our repair and we’re not totally satisfied. So, we added an additional pass of plastic. If this happens to you, don't be alarmed; at any point prior to applying filler and starting finish work, you can do the same by repeating the steps highlighted earlier in this video.

Apply Plastic Magic adhesion promoter. If filler is necessary, apply Polyvance’s 2020-T SMC Hardset Filler. Once cured, sand smooth with 80 and 180 grit sandpaper. On the backside, use a die grinder to remove any excess plastic. Finally, you're ready to prime and paint. As you can see, this repair is really no different from any other that you may encounter, and Polyvance has products that will help you every step of the way.

Look to Polyvance for all of your plastic repair product and training needs. We offer I-CAR Industry Training Alliance courses, as well as other hands-on classes in addition to the video resources you can find on our website and on our YouTube channel.