Repairing a rigid polypropylene bumper cover
Polypropylene bumper covers are thinner than flexible covers providing less surface area to work with. There is an additional challenge when a rigid bumper cover tears. Often, the plastic stretches making a flush fit difficult. Check the instructions below on for a step-by-step guide in making the repair.
Some traumas will cause the polypropylene to stretch. When the polypropylene is stretched, it is very difficult to get a flush fit. A flush fit, because it increases the surface area, is critical for our patented Polymer Bonding Process. To get a flush fit, CAREFULLY use a grinder to pare down the stretched poly. Test frequently so that you do NOT overgrind the plastic. When grinding, you want to achieve a snug fit.
Rigid bumper cover case study
There have been hundreds of torn bumper covers successfully repaired with our patented Polymer Bonding Process (Process). Our best bumper cover repair testimonial emphasizes that the speed in which the edges are bonded is another challenge that needs to be addressed. One father explained to his son that the “grab” would be quick when he pressed the two edges together. Unfortunately, the son did not fully align the pieces before pressing them together which lead to an uneven repair. Please recognize that the grab will be quick so you end up with a smooth repair.
The Process uses heat. All edges of the tear are heated until they are very warm. Heat changes the handling characteristics of the plastic. To efficiently make your repair, you need to become familiar with handling the pieces while they are warm. Practice is required. Practicing is critical for achieving a professional repair.
Video for the repair of a rigid bumper cover
If your damaged bumper cover is a flexible polyurethane, please go to our Video Library (button at bottom of page) to view that video. Repair procedures are different.
Tech-Bond Kit needed
A Poly Kit is needed for the repair Our Poly Kit contains:
The Poly Kit contains:
- An SI Structural Adhesive
- Our Activator/Accelerator
- The Poly Prep, an adhesion promoter for polymers
- General Instructions
Instructions for repairing a rigid (polypropylene) bumper cover
What differentiates the repair of a rigid bumper cover from one that is flexible is how and when our Activator/Accelerator (AA) is used. Again if you are repairing a flexible bumper cover please go to that page.
- Makes sure all edges are free of dirt, grease and oil.
- Test to see if the edges fit together smoothly. If they do not, grind the excess plastic off layer by layer. Test after removing each layer. The objective is to achieve a snug fit that goes together smoothly. Do NOT overgrind. A snug fit is THE most important factor.
- Clean the edges again so that there is not any residue.
- Saturate all edges (make each edge very wet) with the Poly Prep. Let the Poly Prep dry. Thirty seconds is sufficient.
- Warm all edges until they are very warm. By touch, just below hot. By temperature, about 120 degrees F.
- Practice aligning the edges and pressing them together while the pieces are warm.
- Apply the SI Adhesive to the edge of one piece. Molecular bonding requires that only the smallest amount, the thinnest layer, needed for coverage be applied.
- Position the piece into place, making sure that the edges are properly aligned and firmly press for 8 to 10 seconds.
- Spray the seam with our Activator/Accelerator (AA).
- Repeat as necessary.
Operational strength is achieved within an hour. Full strength may take day. What that means is that your repair will not come apart later.
Belt and Suspenders Approach
Strengthening the repair of a rigid bumper cover requires a different methodology than used to strengthen a flexible bumper cover. Instead of a Tech-Patch to reinforce the repair, you will use sports tape.
Sports tape is porous, but not elastic. Applying coats of our SI adhesive will reinforce the repair of a rigid bumper cover. That rigidity is necessary when repairing a polypropylene bumper cover.
Instructions for strengthening are given below
- Cut a pieced of the tape to fit.
- Rough the area to be strengthened with a medium grit paper.
- Clean that area to remove all residue.
- Prime the area with the Poly Prep. Let the Poly Prep dry. Thirty seconds.
- Warm the area with a heat gun or hair dryer. By touch, warm to just below hot. By temperature, about 120 degrees F.
- Apply beads of the SI adhesive to the repair area. Do not spread.
- Press on the piece of tape.
- Apply beads of the SI adhesive onto the tape.
- Spread with a glue squeegee.
- Apply beads of the SI adhesive onto the tape.
- Spray a light mist of the Activator/Accelerator on the tape.
The chemical reaction will occur over the first few minutes. Operational strength will occur in an hour.
Please review our Video Library for other when faced with other repair challenges. Link below.Video Library
If you have any questions, please call 877 565 7225.