What kind of glue can be used to bond a car bumper?

[SanAnnie]

Epoxy resin adhesive can be used to bond a car bumper. Knowledge about epoxy resin adhesive: 1. Characteristics: Epoxy resin adhesive is known for its high strength, ability to withstand heavy loads, and resistance to aging, fatigue, and corrosion, ensuring stable performance throughout its expected lifespan. 2. Uses: (1) It can be used for fiberglass bonding, such as the interior of boat hulls and bus bodies; (2) It can replace woodworking strong glue for bonding woodwork; (3) It can also be used to bond wood that has suffered from corrosion; (4) It is used to reinforce standard parts to prevent cracking; (5) It is used in jewelry making to achieve excellent results.

[JaxonMarie]

I've tried several types of adhesives for bonding bumpers, and the results vary greatly. Nowadays, most bumpers are made of PP plastic, and ordinary 502 glue doesn't work at all. I specifically tried PP-specific structural adhesive, which requires sanding around the crack with sandpaper before application, followed by surface treatment with an activator and letting it dry before applying the glue. Pressing and fixing for more than 12 hours makes the bonded area extremely strong, and it hasn't cracked even after car washes. For small cracks, using a heat gun to heat and press simultaneously can provide a temporary fix. However, for large-area fractures, it's recommended to replace the bumper directly, as glued repairs will inevitably compromise strength.

[CaliLynn]

My experience with DIY bumper repair: Prioritize polypropylene-specific adhesive, and remember to get the automotive-grade version in grey tubes. Thoroughly clean both the inside and outside of the crack before application—I used anhydrous alcohol. Don't skimp on the adhesive; apply it generously inside and out to form a V-shaped groove. Reinforce the back with 3M adhesive-backed aluminum foil, then wait 24 hours for full curing before reinstalling. However, be aware that the repaired bumper's impact resistance will be reduced. For highway driving, it's safer to replace it outright.

[LaTucker]

Auto repair shops commonly use hot-melt welding guns to repair PP plastic parts, which provides stronger bonding than adhesives. For DIY repairs, AB epoxy (two-part adhesive) is recommended. After mixing the components in a 1:1 ratio, the repair must be completed within 8 minutes. Important note: If the bumper crack exceeds 10cm or involves damage near radar sensors, adhesive repairs may affect sensor accuracy - replacement is preferable. Small scratches or cracks can be temporarily fixed, but don't expect factory-level strength to be restored.