6 months ago

DIY Cracked Bumper Repair

DIY car bumper repair

No one wants a cracked bumper, but almost everyone faces them at some point or another. 

A cracked bumper usually means up to $400 in repair bills and a day of not having your car. On top of that, you might have to pay more for insurance after you get the claim. 

But luckily, there’s a solution for you. 

You can fix a cracked bumper on your own. Yes, you read that right! You can do it by yourself!

As a matter of fact, repairing a cracked bumper is way easier and simpler than you think. Just like we made fixing a dent on your car simple for you, today we’ll do the same for cracked bumpers.

There are three DIY approaches that you can use to restore your bumper to its former condition.

  1. The Zip Tie Method (for a severely damaged bumper).
  2. The Plastic Solvent Method (for a mildly damaged bumper).
  3. The Soldering Iron Method (for small cracks and minor repairs).

Let’s learn about all these methods in detail.

DISCLAIMER: If you’re not a DIY car enthusiast or you think you cannot do this repair by yourself, you should consult a professional mechanic. In case you decide to do it on your own, be very careful. Plastic solvents and soldering irons are dangerous for the skin. So, exercise extreme caution when carrying out the repair.

#1 The Zip Tie Method: Repairing a Severely Damaged Bumper   

If you have a bumper that has a large crack, it is not a cosmetic problem anymore. 

When going at highway speeds, the broken pieces can detach from the body of the car and be a serious road safety hazard for you and other drivers. 

This is where the Zip Tie method can help you. Though the result might not be visually appealing to some, it will make your bumper safe to a great extent. 

Also, if you want to know how to fix a cracked bumper without removing it, this is the method for you.

Things You’ll Need

  • A drilling machine with a 3mm drill bit 
  • A bunch of zip ties, depending on the size of the crack you are repairing

The Zip Tie Method in 4 Steps

1. Align the Broken Pieces: Align the cracked pieces so that there is no or a minimum gap between them.

2. Mark Points to Drill Holes: Take a permanent marker and mark points on both sides of the crack. You need to keep the holes at approximately half an inch distance from each other. Make sure you are at least an inch from the crack so that the plastic has enough strength to hold the zip ties in place.

3. Drill the Holes: Take a drill machine and carefully drill holes on all the points you marked in the last step.

4. Tie the Bumper Down: Thread the zip ties through the holes in such a way as to have the tie portion on the back. Take your time to do it in a nifty manner. You can also get creative and use a criss-cross pattern or a contrasting zip tie color to repair a part of the car’s decor.

That is how to repair a cracked bumper –  an extremely damaged one. For some people, this method won’t be ideal, but the bumper will be safe to drive with until they can get a new one. 

#2 The Plastic Solvent Method: Repairing a Mildly Damaged Bumper 

When a bumper is mildly cracked and has sufficient structural strength, it can easily be restored to its former glory. You can use the plastic solvent method to fix a cracked plastic bumper of any kind – and it will be as good as new. 

Things You’ll Need

  • Tools to remove the bumper. These will depend on the car you have. 
  • Plastic solvent kit matching the type of plastic your bumper is made from. You can see the backside of the bumper for the plastic specification stamp.
  • 80, 120, 500, and 1000 grit sandpapers
  • Isopropyl (rubbing) alcohol
  • Paint filler
  • Paint primer
  • Paint to match the color of your car
  • Clear-coat for the paint

The Plastic Solvent Method in 10 Steps

1. Remove the Bumper from the Car: In order to fix a cracked bumper on a car using a plastic solvent, you’ll first need to remove it from the car. Be careful while doing this. The bumper is attached to the car with plastic tabs, and if you happen to damage one, you’ll also have to learn how to fix broken bumper tabs. 

2. Prepare the Surface: Once the bumper has been removed from the car,  use the 80 grit sandpaper to sand off the inside of the bumper where it’s cracked. Make sure you get a clean and rough surface, and the edges of the crack are free of any contaminant. Once you have sanded it down, use rubbing alcohol to clean the whole surface.

3. Apply the Plastic Solvent: Follow the instructions on the plastic solvent kit and prepare the solvent. Once the solvent is ready, double-check to make sure the bumper is clean. Apply a generous amount of solvent on the inner side of the bumper. The solvent will dissolve the plastic from both sides and make it one piece. You can think of it as welding.

4. Let the Solvent Cure: Let the solvent work for the required amount of time as per the instructions. You can use these steps to fix broken bumper clips, too, in case they are also damaged. The bumper is ready once the solvent has been cured. After that, you need to fix the cracked paint on the bumper. If you’ve seen our post on fixing scratches on your car’s paint, this will be easy for you.

5. Fill the Gap: Once the solvent has cured, prepare the filler and fill the crack from the outside using a scrapper. Let the filler cure for the time specified in the instructions.

6. Sand the Filler: Once the filler is dry, use the 120 grit sandpaper to sand off the filler so that it is flush with the bumper’s profile. Next, use the 500 grit paper to smooth the filler further.

7. Sand the Clear Coat: Using 1000 grit sandpaper, sand the area surrounding the crack and the filler. This will give the new paint a good surface to bond to. 

8. Apply Primer: Spray an even coat of primer on the freshly sanded surface. It’s generally recommended to spray from around 10 inches away and go in parallel lines over the area. However, detailed instructions can be found on the primer can. Let the primer cure before you proceed.

9. Paint the Bumper: Apply an even coat of paint to the area where you just applied the primer. Let it dry and apply another coat. 

10.  Apply a Clear Coat:  Apply a thin coat of the clear coat on top of the paint to finish the job. That’s how to fix a cracked bumper.  You did it!

If you have a really small crack, and the area does not require much structural strength, you can use a soldering iron to fix it.

#3 The Soldering Iron Method: Fixing a Small Crack In Bumper 

Heat melts plastic, and if you melt both sides of the broken bumper and make them solidify together, it can easily fix a minor crack in the bumper. 

Things You’ll Need

  • Tools to remove the bumper. These will depend on the car you have. 
  • 400W soldering iron
  • 80, 120, 500, and 1000 grit sandpaper
  • Isopropyl (rubbing) alcohol
  • Paint fille.
  • Paint primer
  • Paint matching the color of your car
  • Clear-coat for the paint

The Soldering Iron Method in 4 Steps

1. Remove the Bumper: Take the bumper off the car. Be careful when doing this, do not break the bumper clips or enlarge the crack.

2. Prepare the Surface: Wash the broken area and sand it down with 80 grit sandpaper to get a good bonding surface.

3. Melt and Join the Bumper: Make sure the soldering iron is sufficiently hot. It will take around five minutes to heat after you plug it in. Go on the inside of the bumper and melt the broken edge from both sides. Press the pieces together while the plastic is still molten. Repeat this until you join the whole cracked area.

4. Paint the Bumper: Once you have repaired the bumper, use steps 5-10 of the previous method to paint the bumper.

 You Did it!

These are the easiest methods that you can use to repair a broken or cracked bumper no matter how bad the problem is. If your bumper is in extremely bad shape, zip ties are the best option and for lesser damages, you can use a plastic solvent or a soldering iron.

Frequently Asked Questions

Can you fix a cracked bumper on your own?

Yes, you can repair a cracked bumper on your own if you have the tools and materials required to do it.

How can a cracked bumper be fixed at home?

A cracked bumper can be fixed at home by three methods: Zip Tie, Plastic Solvent, and Soldering Iron. You can use any of these methods, depending on the extent of the damage.

How much does it cost to repair a cracked bumper? 

The cost of repairing a cracked bumper is between $250-350, depending on the make and model of your car and the extent of damage to the bumper.

Can you fix a cracked bumper without replacing it?

Yes. If the bumper is not totally destroyed, it can be fixed.

What is the best way to fix a cracked plastic bumper?

The best way to repair a cracked plastic bumper is using a plastic solvent. It returns the bumper to its original strength, retains the cosmetic appearance, and is easy to do.

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