Fast, Flexible Resources from 3M
There’s a lot more to a vehicle than metal panels. So, to maintain the right balance of speed, strength and adaptability in your shop, it’s vital to maintain expertise in bumper and plastic panel repair. From rigid to semi-rigid plastic repair, from fixing simple bumper scuffs to two-sided bumper repairs, 3M delivers tips, articles, videos and standard operating procedures (SOPs) to help you get the job done, efficiently and to specific OEM standards.
Here is simple, easy-to-follow information, including best practices for a full range of plastic and flexible bumper repairs. You will find step-by-step SOPs for cosmetic bumper repair, two-sided bumper repairs for fixing cracks and tears as well as repairing plastic bumper tabs.
Along with the abrasives, adhesion promoters, semi-rigid plastic repair materials, flexible adhesives and the procedures to use them for professional bumper and plastic panel repair, 3M provides tech tips to help you achieve true excellence. Check them out here.
Discover the best ways to repair minor scrapes and gouges in plastic bumpers. 3M designed these resources to guide you all the way through the process, from initial prep sanding through filler application and final inspection. You’ll discover when to use adhesion promoters, as well as the correct abrasive grits for dish-outs and flexible filler sanding. These SOPs detail one-sided repairs such as scratches, bubbling and minor spider cracking that does not penetrate plastic parts. Damage such as cracks and tears that penetrate the bumper should be considered two-sided repairs.
Often, a broken or missing plastic tab can necessitate a costly full part replacement. 3M provides simple, step-by-step SOPs to make replacing plastic tabs fast and reliable. This allows you to preserve, not replace, existing bumpers or other plastic parts. View best practices for preparing broken tabs and restoring them to their original strength and function. Plastic tab repair is excellent for bumpers as well as parts in headlight or grille mounting areas.
Here are some best practices for bumper repairs which require reinforcement as well as flexible repair material. View how-to information on tools, techniques and products such as 3M™ Flexible Patch and 3M™ EZ Sand Flexible Parts Repair.
Here is the art and science of repairing plastic bumpers with significant tears, cracks and gouges. These 3M SOPs show best practices and products, such as 3M™ Semi-Rigid Plastic Repair material, for sanding and filling while alsomaintaining the shape and strength of the plastic.
Here are some valuable insights into specific plastic bumper and parts repair challenges, including quick tips on preventing common issues such as bubbling and insufficient adhesion. For more in-depth information, click the link below each tip.
Customer Challenge: What is the best way to ensure a plastic bumper tab rebuilt with 3M™ Super Fast Repair Adhesive, PN 04247 will adhere reliably to a bumper surface?
Technical Tip: Beyond proper surface prep – typically, grinding to a knife edge with a 3M™ Roloc™ 60+ grade disc and following with a 3M™ Cubitron II™ 80+ grade DA disc until a “fuzzy” surface is achieved – an established best practice is to drill several 1/8” holes at the base of the new tab near the edge of the bumper. This is commonly known as “pinning.” This will allow the adhesive to flow through the bumper and bond with itself for added strength – almost like creating a liquid rivet or bolt securing the replacement tab to the bumper. Also, always use an adhesion promoter such as 3M™ Polyolefin Adhesion Promoter, PN 05907 before adhesive application.
Customer Challenge: My shop has recently had several callbacks related to bubbling in plastic bumper repairs. We repaired all bumpers using 3M™ Semi-Rigid Repair Adhesive, PN 04240. What could be causing this bubbling?
Technical Tip: Maintaining clean surface areas is always important in collision repair; thoroughly clean the repair before any sanding steps. After sanding, only use clean, dry compressed air to clean the repair area. Solvents can be absorbed into the plastic and release over time, causing bubbles in the repair area. Additionally, the application of polyester based body fillers over some plastic repair materials can lead to bubbling. It’s best to follow 3M SOP and perform final filling over repair adhesives with 3M™ EZ Sand Flexible Parts Repair material.
Customer Challenge: Our shop has attempted to repair bumpers on several occasions, but we are experiencing problems. Either the repair is visible after the paint cycle or the bumper re-cracks during installation. What could we be doing wrong?
Technical Tip: A good repair starts with a good foundation, and surface prep is your foundation. It’s very important when repairing a deep gouge or a tear that goes all the way through the plastic to make a wide, gradual taper. A proper taper on the cosmetic side of a bumper should be deep enough to expose about ¼ inch wide strip of the patch on the back side of the part. Changes in temperature will cause the adhesive to expand and contract and pull away from the sharp edge of a “V” groove causing a ghosting line to appear. With a gradual taper there is no sharp edge where the plastic will separate from the adhesive. Also a “V” groove is too narrow for the adhesive to bond to.