Urethane Front Bumper Repair

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This front "Mach 1 - type" bumper repair write-up got lost in a long thread that went about 4 different directions.

So I thought I'd capture and repost (C9zx) Chuck's repair instructions:

"... . I make no claim to be an expert at body work, or anything else for that matter. What I'm describing is the repair of relatively minor damage (no big chunks missing). The bumper must be sanded to bare urethane, DO NOT USE PAINT STRIPPER OF ANY KIND. I used a DA with 100 grit peel and stick, keep it moving. Do not linger in one spot too long. If you don't have a DA, use a 3M rubber sanding block. If you have long narrow cracks you will need to "Vee" them out (I used a Dremel tool with the miniature cut off wheel). Nicks and gouges need to be free of loose small pieces. Clean everything with wax and grease remover then wipe again with clean dry cloth. The repair material used is an inexpensive alternative to the commercial 3M material and pricey special "gun". It is BONDO Company (now owned by 3M) but it is not bondo. It is PN 280, Bumper Repair Kit. It is flexible 2 part epoxy in a plastic syringe, about $7.00. It is only about an ounce and a half, so only mix what you need at the time. It cures in an hour. Wet sand with 180 or 220 on the block. When you are satisfied that you have repaired all the damage clean everything again and apply the primer. The primer is the key part of this repair. I used Sherwin Williams Spectra Prime with "Ure-flex". When dry, apply a tracer coat. Sand with 320 or 400 on the block. If you find you have missed something that a second coat of primer will not take care of, use more epoxy and repeat process. When satisfied, apply final primer coat. Apply compatible top coat. I used base clear. Final "color sand", compound and polish. I used the 3M series of finishing products. I hope this helps.

Good Luck,


Thanks again to Chuck for this how-to post from quite a few years ago.  I fully trust these techniques/steps because the bumper still looks new today!

Here are a few in-repair process pics:

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Here is another similar thread:   https://www.7173mustangs.com/thread-urethane-bumper-repair




  • Chucks 72 Mach 1 edit.jpg
    Chucks 72 Mach 1 edit.jpg
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