Automotive Structural Plastic Repair

In accidents where a rip or tear has occurred in the plastic bumper of the vehicle, you must first repair the gash, before polishing it to look good as new. For a structural plastic repair, follow the steps below for a high quality finish in the shortest time possible.



Prepare the Surface to be Worked On

First clean the repair area with auto wash and rinse, followed by a non-solvent based cleaner and dry thoroughly. For best results, use when the temperature of the product and the surface is between 70°F and 75°F (21°C and 24°C). You want to eliminate all contaminants so that they are not later sanded into the plastic.

Best Practices - Plastic Repair - Step 1


Sand the Repair Area

Sand the surrounding areas (at least two inches around the rip or tear area on both sides of the bumper) at a low speed with 80 grit sandpaper on a Dual Action (DA) sander. Be sure to round off the edges of the rip or tear, and then blow off with clean dry air. Do not use any cleaners after the area has been sanded. 

*An experienced professional tip is to not use any cleaners after the damaged area has been sanded. 

Best Practices - Plastic Repair - Step 2


Apply Adhesion Promoter

Apply adhesion promoter and wait 10 minutes or flash off with a heat gun, being very careful not to overheat the part.

Best Practices - Plastic Repair - Step 3


Apply Masking Tape

Apply masking tape to the front side of the damaged area to keep adhesive from squeezing through the tear. Cut a piece of nylon tape, 1" beyond all edges of the tear, and set it aside to have handy later.

Best Practices - Plastic Repair - Step 4


Purge Cartridge and Mix with Tip

Purge the epoxy adhesive to ensure both cartridges are flowing. Do this with the manual applicator gun without the mixing tip attached. Attach the mixing tip and equalize the adhesive until a consistent color is achieved, which indicates the proper mix.

Best Practices - Plastic Repair - Step 5


Apply Adhesive Material and Patch

Apply adhesive to the prepared area, keeping in mind the “work window” of the product. Apply the nylon tape you earlier cut one inch beyond all edges of the damage. You may apply the nylon tape first, and then follow by applying the adhesive – either method is acceptable.

Best Practices - Plastic Repair - Step 6


Spread Adhesive Over Patch

Using a mixing spreader, spread the adhesive flush within the surface and apply pressure to ensure the patch has good contact and to eliminate air pockets. Once the adhesive has cured, remove the masking tape from the front side and sand with 80 grit sandpaper to remove any tape residue or adhesive that may have squeezed through. Blow off with clean, dry air and proceed to the Cosmetic Repair Best Practice’s to complete the job.

Best Practices - Plastic Repair - Step 7


The vehicle is now ready to move on to painting and detail before being returned to the customer.



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