How To Fix A Cracked Plastic Bumper With Fiberglass

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Fiberglass bumpers are important safety devices designed to protect your vehicle from impairment. Because they do this by absorbing shocks and impacts, you may need to repair your bumper every one time in a while. Thankfully, the repair process is incredibly straightforward, and doing it at home can help you save hundreds of dollars on labor.

one
Disable the airbag if you're removing the front bumper. To avert accidentally setting off the airbag, y'all'll need to disable information technology earlier starting the front bumper removal procedure. To do so, open the hood of your car and disconnect the battery, negative side first. So, popular off the steering bike cover by pressing the wheel's eject button with a specialty removal tool. Inside, look for a small-scale power box, take out the screws or bolts holding it in place, and remove the continued wires, thus disabling the airbag.^[1]
- If you cannot locate an eject push button or power box, check your vehicle's driver transmission for model-specific instructions.
2
Take off any screws, nuts, or clips holding the bumper in place. For front bumpers, these are typically located directly above the bumper (under the hood), below information technology, and at the commuter and passenger-side ends. For rear bumpers, wait below the bumper, on the outer surface, and inside the body.^[2]
- To avoid problems when reattaching the bumper, have pictures showing where all the fasteners go.
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iii
Slide the bumper off your car. In one case you lot've removed all the exterior fasteners, gently pull on the left or right side of your bumper until it pops out. Using a screwdriver or other flat object, keep the inside of the bumper any remove any additional clips holding it in identify. Then, simply slide off the bumper.
- Depending on the model of auto, you may need to have off other elements, such as fog lights, to fully remove the bumper.

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Grind down the raised surface along big cracks. Mountain a flat grinding head on a handheld dice grinder, then use it to remove the surface roofing the front and back of big damaged areas. Make sure to grind downward whatever sharp or loose edges along the cracks. And so you lot can fix the bumper properly, use the edge of the grinder to create a thin, clear groove along each damaged spot.^[3]
- Stray fiberglass particles can harm your eyes, lungs, and any exposed pare. To avoid this, wear thick gloves, long-sleeved clothing, goggles, and a grit mask while working.
2

Sand down the raised surface along small cracks. Unlike big cracks, small damaged areas may be hard to grind without farther damaging the bumper. To get around this, sand the areas downwardly using 600 dust wet and dry sandpaper. Look for this specialty sandpaper at an auto repair, abode improvement, or hardware store.^[iv]
three
Scrub the fiberglass surface with acetone. Acetone is a highly volatile chemic that serves equally a great dirt and grease remover. When applied to your fiberglass bumper, it will remove pre-existing resin so your new materials have a surface to bond with. To strip the surface properly, carefully dampen a rag with acetone, then scrub it over every damaged spot.^[5]
- Acetone is highly flammable, so keep it away from fire and the combustion engine of your car. For condom, article of clothing long-sleeved clothes, rubber gloves, and safe goggles when using it.

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Purchase resin, hardener, and material matting strips. To repair your bumper, you lot volition need fiberglass resin, fiberglass matting strips, and a liquid hardening amanuensis, forth with plastic or wooden sticks to assist mix the resin and a brush or other applicator to put it on the bumper. You tin purchase these separately or in pre-packaged fiberglass repair kits. Expect for the materials at auto supply stores.^[vi]
2

Cutting the fiberglass matting to the size of each cracked area. Catch your material matting and hold it upwardly to a damaged area. Using a fabric marker, make a line on acme of the textile indicating the crack placement. Then, take your fabric to a solid working table and cut information technology using a precision knife. So you have plenty overlap to support the fiberglass, leave about 20 mm (0.79 in) of space effectually the marked expanse. Repeat this with each crack.^[7]
iii
Mix the resin and hardener together. Grab a small container and pour in the corporeality of resin you lot think you'll need to cover a specific slice of fiberglass matting. Then, check the instructions on the back of your resin container and apply the recommended amount of hardening agent. Using a plastic or wooden stick, stir the substances together until they are well mixed.^[8]
- One time combined, about resin mixes stay soft for 8 to 12 minutes, afterwards which they go unusable.
4
Apply the matting to your bumper using the resin mix. Cover the back of a damaged surface area with a sheet of fiberglass matting. Using a brush or other applicator, encompass the entirety of the cloth and about 2.5 inches (half-dozen.4 cm) of the surrounding area with the resin mix. Echo this with each crevice, then permit the matting cure in a moderately warm expanse for about 2 hours.^[nine]
- For extremely big cracks, you may need to apply matting to the front end of the bumper as well.

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Sand down the repaired areas. Once the fiberglass is fully cured, sand downwardly the fixed areas using 600 grit moisture and dry sandpaper. Do this on both sides of the bumper until the fiberglass patches are smooth to the bear on. To avoid breaking open up the new seals, practise non use your handheld grinder.^[x]
2

Cover the fixed areas with auto body filler if necessary. If there are withal cracks or grooves in the bumper after the initial sanding, you lot can ready them with body filler. Gauge how much body filler you need and squeeze information technology into a small loving cup. Mix in the amount of hardening amanuensis recommended on the body filler container, so apply it to the cracks with a plastic squeegee. Smooth the surface if necessary, then permit information technology cure in the sunday for about 15 minutes.^[11]
3

Sand downwards the entire bumper. Once you've successfully filled all the damaged areas, sand the entire bumper down with 600 grit wet and dry sandpaper. The goal is to go every bit uniform a glaze as possible, with no random hills acquired past the fiberglass strips or body filler.^[12]
iv

Repaint the bumper (optional). If you're non happy with how the bumper looks, effort painting it to hibernate the repairs. Cover the bumper with a base of operations coat of white spray paint, then let information technology sit down for about ten minutes. Apply base coats until you can no longer run into the repairs, so spray paint the bumper a similar color to your car. Allow the paint dry for 1 to 2 hours, then spray it with a layer of articulate coat. Your bumper should be ready after 24 hours.^[thirteen]

1

Slide the bumper onto your car. Make sure the bumper is completely dry. Then, lift it up and slide it over the forepart or rear finish of your automobile. Once you have information technology in place, push the bumper forward until information technology can sit down on its own. Starting on the left or right side, walk around the motorcar and push every section of the bumper in until it is flush against the vehicle.
ii

Replace and tighten whatever bumper fasteners. To keep the bumper from coming off, replace any screws, nuts, or clips needed to hold information technology in place. Then, make sure to secure the fasteners with a screwdriver or wrench until they're tight enough that you can no longer motion the tool.^[14]
3

Reconnect the airbag if necessary. If you disabled the airbag, make sure to reattach it earlier driving your vehicle. To practice so, connect the steering wheel ability cords to the ability box, then supercede whatsoever screws or nuts designed to hold the box in identify. Put the steering wheel cover back on, then reconnect your motorcar's bombardment cords, positive side first.^[15]

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Things You'll Need

Screwdriver or wrench (for bumper removal)
Steering wheel removal tool (to disable airbag)
Handheld dice grinder with apartment grinding head
600 grit moisture and dry out sandpaper
Acetone
Cloth rag
Fiberglass resin
Fiberglass matting strips
Liquid hardening agent
Fabric marker
Precision knife
Plastic or wooden mixing stick
Brush or other liquid applicator
Body filler (optional)
Plastic squeegee (optional)
Spray paint (optional)

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Article Summary X

To repair a fiberglass bumper, first remove the fasteners holding the bumper in place, and then slide the bumper off your car. To clean the bumper, strip the surface from big cracks using a dice grinder, sand down pocket-size cracks with 600 grit wet and dry out sandpaper, and scrub the whole bumper with acetone. Using a precision knife, cut out strips of fiberglass matting the same size as your cracks. And then, fix them to the dorsum of the bumper using a mixture of fiberglass resin and a hardening amanuensis. For tips on repainting your bumper, read on!

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