How to repair a car bumper

Whether someone bumped into your car in the grocery store parking lot by mistake or that concrete pole was a little closer than expected, your car's bumper has probably received a bruise or two from regular use.

The amount of shock absorbed by the bumper determines whether the bumper is repairable or not. Some bumpers will flex and others will crack. Luckily, these two types of bumper bruises are repairable in almost all cases, unless the damage is extreme. If the bumper has a lot of cracks or is missing a lot of material, it may be best to replace the bumper itself.

Often you will have to consult with your local bodyshop to determine the extent of the damage, and most bodyshops will provide a free repair estimate. But before you let the body shop fix your car for you, there are some easy ways to fix a damaged bumper yourself using a few items you might already have at home.

Part 1 of 2: Repairing a sagging bumper

Necessary materials

• Heat gun or hair dryer (usually a hair dryer is safer for this procedure, but it is not always suitable)
• socket
• Jack stands
• Long mount or crowbar
• Safety glasses
• Work gloves

Step 1: Raise the vehicle and secure it with jack stands.. To secure the jacks, make sure the jacks are on a firm surface and use the jack to lower the weld or the car's inner frame so they rest on the jack. More information on jacking can be found here.

Step 2: Remove the mudguard. If applicable, remove the under vehicle mudguard or fender guard to gain access to the rear of the bumper. The mudguard is attached with plastic clips or metal bolts.

Step 3: Warm up the injury. Use a heat gun or hair dryer to evenly heat the damaged area. Use the heat gun until the bumper becomes pliable. It takes only about five minutes to heat the bumper to a temperature at which it becomes flexible.

• A warning: If you are using a heat gun, be sure to keep it 3 to 4 feet away from the bumper as it heats up to high temperatures that can melt the paint. When using a hair dryer, the bumper is usually hot enough to become flexible, but not hot enough to melt the paint.

Step 4: Move the bumper. During heating, or after you have finished heating the bumper, use a pry bar to pry the bumper from the inside out. You should notice that the indented part starts to pop out when you push with the crowbar. If the bumper is still not very flexible, warm the affected area until it becomes pliable.

• Functions: It can be helpful to ask a friend to heat up the bumper while you use the pry bar.

• Functions: Push out the bumper evenly. Push out the deepest areas first. If one part of the bumper fits well into its normal shape and the other does not, adjust the pry bar to increase pressure on the part that is more recessed.

Repeat this process until the bumper returns to its normal curvature.

Part 2 of 2: Cracked Bumper Repair

Necessary materials

• ¼ inch drilling tool
• Air compressor suitable for use with tools (you will only need an air compressor if you are using pneumatic tools)
• angle grinder
• Body filler type Bondo
• Drill or dremel to match the digging tool
• Respirator
• socket
• Jack stands
• Paper or newspaper for masking
• Brush
• 3M Paint Prep Cleaner or XNUMXM Wax and Grease Remover
• Plastic or fiberglass bumper repair kit (depending on the type of material used in your car's bumper)
• Spatula or Bondo spatula
• Sandpaper (180,80, 60 grit)

• Tape with moderate adhesive properties

• Functions: When fiberglass bumpers crack, they will leave visible fibers of fiberglass around the edges of the cracked area. Look inside the cracked area of ​​your bumper. If you see long white hair, it means that your bumper is made of fiberglass. If you are not sure if your bumper is made of fiberglass or plastic, consult your local bodyshop or call your dealer and ask for bumper design specifications.

• A warning: Always wear a dust mask when working with fiberglass or sanding material to prevent inhaling harmful and sometimes toxic particles.

Step 1: Raise and secure the car. Jack up the car and secure it with jack stands.

Remove bumper for easy access.

Step 2: Clear the area. Clean off any dirt, grease, or soot from the front and back of the affected area. The cleaned surface should extend approximately 100 mm from the crack.

Step 3: Remove excess plastic. Use an angle grinder or cut-off wheel to remove excess fiberglass hairs or plastic roughness. Use the cut-off wheel of an angle grinder to straighten out hard edges as much as possible. Use a dremel with a burrowing tool to get to hard to reach places.

Step 4: Sand the damaged area with 60 grit sandpaper.. Sand up to 30mm around the repaired area for plastic and 100mm for fiberglass bumpers.

Step 5: Remove excess dust with a rag. If you have an air compressor, use it to blow off excess dust from the surface.

Step 6: Prepare the site. Clean area with 3M Paint Prep or Wax & Grease Remover.

Remove the contents from the bumper repair kit.

• Attention: If your bumper is plastic, skip to step 14.

Step 7: Cut 4-6 pieces of fiberglass sheets about 30-50 millimeters larger than the affected area.

Step 8: Mix catalyst and resin.. Mix the catalyst and resin according to the instructions provided with the bumper repair product. After proper mixing, you should see a color change.

Step 9: Apply Resin. Using a brush, apply the resin to the repair area.

• Functions: Make sure the entire repair area is wetted with resin.

Step 10: Carefully Cover the Area. Apply fiberglass sheets layer by layer, adding enough resin between layers.

• Functions: Apply 4-5 layers of fiberglass sheets. Squeeze out air bubbles with a brush. Add additional layers of sheets for added strength.

Let dry for 10 minutes.

Step 11: Coat the Front. Apply resin to the front of the repaired area. Let it dry for 30 minutes.

Step 12: Sand the front of the area to be repaired.. Sand the front of the repaired area with 80 grit sandpaper. Sand the lumpy, uneven resin formations to match the bumper's normal smooth curvature.

Step 13: Clear the area. Clean repaired area with 3M Paint Prep or Wax & Grease Remover.

• Attention: If your bumper is made of fiberglass, you can start applying putty. Please go to step 17.

Step 14: Mix the contents of the repair kit. To repair a plastic bumper, mix the contents according to the instructions included with the repair kit.

Step 15: Tape cracked surfaces together.. On the front side of the repair area, use tape to pull the opposite edges of the cracked surfaces together. This will add more stability during repairs.

Step 16: On the back of the repair area, use a putty knife or Bondo putty knife to apply the bumper repair product.. When applying the repair product, tilt the spatula so that the product is pushed through the crack and squeezed out through the front. Make sure you cover the area extending about 50 millimeters from the crack.

Let dry for the time recommended by the repair kit manufacturer.

Step 17: Prepare and mix body filler according to package directions.. Apply several coats of putty with a trowel or Bondo trowel. Create a surface using 3-4 napkins. Give the layer styles the shape and outline of the original bumper.

Let it dry according to the repair kit manufacturer's instructions.

Step 18: Remove the Tape. Start peeling off the tape and remove it from the bumper.

Step 19: Sand the Surface. Sand with 80 grit sandpaper, feeling the surface as you sand, to see how the repair progresses. As you grind, the surface should gradually move from rough to almost smooth.

Step 20: Use 180 grit sandpaper to prepare the repair area for priming.. Sand until the repair is even and very smooth.

Step 21: Clear the area. Clean repaired area with 3M Paint Prep or Wax & Grease Remover.

Step 22: Prepare to Apply the Primer. Using paper and masking tape, cover the surfaces surrounding the repaired area before applying the primer.

Step 23: Apply 3-5 coats of primer. Wait for the primer to dry before applying the next coat.

The renovation work has now been completed. All your bumper now needs is paint!

If you follow the instructions correctly, no one will ever be able to tell that your car's bumper has been damaged. By doing this repair process yourself, you can cut nearly two-thirds of your body repair bill!