- How To Repair A Plastic Bumper Crack Tool
- How To Repair Cracked Plastic Bumper Bar
- How To Repair A Plastic Bumper Crack Repair
- 3m Plastic Bumper Repair Kit
- Cracked Bumper Repair Kit
Cracked, dented, punctured and scratched. These are all ugly things that can happen to your car bumper. More accurately called a 'bumper cover,' these decorative plastic components hide the metal structural bumper components underneath. Bumper covers are easily damaged (whatever happened to those chrome bumpers that really could take some bumps?), and the best way to fix yours depends on your situation, your abilities and the kind of bumper damage you've got.
This epoxy applies directly to rips and cracks in flexible auto parts such as bumpers and bumper covers, with a working time of only 6 minutes for fast, easy repair and restoration. For filling larger holes, the versatile formula works as a filler; simply apply the paste. If your plastic bumper has scuffs and scratch damage, the repair can be carried out just on the front side of the bumper. However, any cracks or splits should be repaired from the front and back. Make sure you work in a dry place like a garage and take your time with the process – it can be fiddly but rushing it will create a bad finish. Jun 17, 2020 To prep the bumper, grind away the paint and rough edges, then cut a V-groove along the crack on both the front and back of the bumper. That gives the filler material more surface area to. Prepare the back of the plastic item by scuffing it with 50-grit sandpaper to ensure an effective bond. Cover the front of the item - which is the visible part - with tape or something else to act as a backing for the adhesive. If it's a large crack, you may want to tape a piece of thin-gauge metal or plastic over the crack.
Bumper Fix No. 1: Repair the Scratch
Scratches happen, but shallow ones that don't go all the way through the paint are easily eliminated with buffing. This goes for shallow scratches anywhere on your car, not just bumper covers. Any auto body shop or detailing center can buff out scratches for you, and this often works well. Cost typically varies from $50 to $200. You can also buff yourself using an electric automotive polisher ($70) along with the finest grade of auto polishing compound ($20). A variable speed 6-in. random orbit woodworking sander ($125) fitted with a buffing pad also works great as a polisher.
Bumper Fix No. 2: Replace the Bumper Cover
If you've got a crack or puncture in your bumper that's more than a few inches long, replacement is considered the proper approach. The damaged bumper cover comes off by releasing hidden fasteners and clips around fenders and neighboring parts. Once the cover is removed, then a pre-painted new cover can be snapped on. Sounds simple, but there are three challenges you need to know about.
First, replacement bumper covers aren't cheap, especially if you go with a cover made by the original equipment manufacturer (OEM) and factory pre-painted to match your vehicle. You can certainly find aftermarket bumper covers for less money, but you'll almost certainly have to have it painted to match your car, boosting the final cost.
Second, getting the old bumper cover off without damaging the surrounding body work isn't easy because all the fasteners and clips are hidden.
And third, even with an economical aftermarket bumper cover, it's not that easy to create your own matching paint job.
Bumper Fix No. 3: Patch the Bumper Cover
Although bumper covers are typically made of semi-flexible plastic, you can fill, sand, paint and buff bumper dings and dents the same way as any steel auto body part. Patching can save you money, compared with complete bumper cover replacement, and it's an approach that's DIY friendly, too.
There are two prerequisites to keep in mind as you decide if patching is for you. First, there should be no damage to the underlying metal bumper structure. If damage to the cover is small, then patching with conventional, catalyzed auto body compound is an option. That should even work on a big puncture localized in one place.
The second thing: Bumper covers need to be stabilized before they can be patched, sanded and made to look like new. Bumper covers are flexible enough to bend inwards when you push them. If movement like that happens after patching, it will cause the auto body filler to crack and fall out.
Stabilizing the cover by injecting expanding polyurethane foam inside is a great way to make the cover firm in the area where a repair is required. Just be sure to inject only a small amount of foam at first, let it harden, then add more and let it harden. Filling the area behind the bumper cover with foam in one go will cause too much pressure and an outward bulging of the plastic. Painting and buffing are final steps to complete a bumper patching job.
Follow MSN Autos on Facebook and Twitter
Fix a cracked bumper
So you hit the parking ramp barrier and now you have a cracked bumper? The body shop wants a fortune and you want to fix a cracked bumper yourself. You’ve searched the Internet and watched all the youtube videos that show you how to fix a cracked bumper yourself. DON’T DO THAT!If you follow the instructions in those videos you’ll be wasting your time and energy. All the posts and videos show the same thing; using epoxy and Bondo to fix the crack. Those products won’t last and they’re incompatible with the plastic used to make the bumper cover. Epoxy and Bondo are rigid materials. But your bumper cover is made from a flexible plastic. If you use those products, they’ll break off the instant your bumper flexes. The crack will open up again and you’ll have to redo the repair from scratch.
What you need to repair a cracked bumper
If you want to repair your cracked bumper the right way you’ll have to spend some money on a crack stitching tool and a special plastic welding kit. A plastic welding kit contains a hot iron that will melt the bumper plastic but not destroy it. You’ll also have to remove the bumper from the vehicle, so you should have access to a shop manual to locate all the bumper cover fasteners. Try alldata or Mitchell (see the links below). Next, take a moment to understand bumper construction.
Understanding bumper construction
The bumpers on modern vehicles are made with three pieces; the bumper cover (which is the part that cracked), the energy absorber (which probably also got damaged during the impact) and the impact bar (the actual bumper). Here are illustrations for a front and rear bumper from a 2015 Toyota Camry. You can see that the bumper has three components: bumper cover, energy absorber, and the impact bar.
Three-piece bumper construction
The bumper cover material is made from flexible plastic. But car makers use a variety of plastics to form their bumper covers and the filler plastic you use to repair the crack must match the base material. If you use any other type of filler to fix a cracked bumper cover, it won’t last. It will simply crack off. Here’s a list of the most popular materials:
How To Repair A Plastic Bumper Crack Tool
TPU TPUR = Thermoplastic Polyurethane
It’s used in bumper covers, soft filler panels, gravel deflectors, rocker panel covers.
It’s used in bumper covers, soft filler panels, gravel deflectors, rocker panel covers.
TPO, EPM or TEO = Polypropylene + Ethylene Propylene rubber
It’s used in bumper covers, valence panels, fascia panels, air dams, dashboards, grilles.
It’s used in bumper covers, valence panels, fascia panels, air dams, dashboards, grilles.
PP=Polypropylene (polyolefin)
It’s used in bumper covers, deflector panels, interior moldings, radiator shrouds, inner fenders
It’s used in bumper covers, deflector panels, interior moldings, radiator shrouds, inner fenders
PC + PBT= Polyphenylene Ether + Polyamide Bumper covers
If you use any other type of filler to fix a cracked bumper cover, it won’t last. It will simply crack off.
Do some Internet research or use a shop manual to determine the type of plastic used in your bumper cover.
Steps to fix a cracked bumper
The advice on the Internet shows how to patch the bumper crack by first removing the bumper and applying 2-part epoxy covered with fiberglass cloth or drywall mesh. Trust me, that method won’t work. Here’s why. Drywall mesh isn’t strong. Don’t believe me? Just try pulling it apart with your fingers. The mesh comes apart in your fingers. If you’re going to use any kind of backing material with the crack repair, at least choose a stronger fabric like fiberglass cloth or stainless steel screen. They offer lateral support that drywall mesh doesn’t.
Stitching the crack from the backside is the first step in the crack repair. There are two ways to do this and both require you to remove the bumper from the vehicle.
Stitch a cracked bumper with hot staples
The hot staple method is the fastest and most long-lasting. Start by clamping cleaning the cracked edges with a wax remover. Then close the gap between the two cracked sections and clamp them together using small wood blocks and a vice grip type locking pliers or wood clamp.
Next, load a staple into the heat gun and press the trigger. Wait
Astro Hot Staple Gun 7600 Kit
for the staple to get red-hot and plunge it into the middle of the crack to a depth of no more than half the thickness of the plastic. Allow the staple and plastic to cool before releasing the staple from the gun. Repeat the operation by alternating the staple rotation direction. Once you’ve stitched the crack, cut the protruding staple legs with a side cutter.
How To Repair Cracked Plastic Bumper Bar
Find the Astro 7600 Hot Staple Gun Kit for Plastic Repair Kit on Amazon for about $90. It comes with the heating gun and an assortment of stitching staples. See this video below for usage.
Fill the cracked bumper from behind with plastic welding rod
Just like with hot staple stitching, you must remove the bumper cover from the vehicle to stitch the crack with plastic welding rod. Instead, purchase a plastic welding kit like the Polyvance 5700HT Mini Weld Model 7 Airless Plastic Welder. The kit comes with all the types of bumper cover plastics commonly used by car makers
6027 HT Standard Welding Tip
6031 Tear Drop Airless Welding Tip
200 Watt Ceramic Core Heating Element
2045W Reinforcing Mesh
6124WB Stainless Wire Brush
Starter Pack (15 ft) of round Polyurethane Welding Rod
Starter Pack (15 ft) of round Polypropylene Welding Rod
Starter Pack (15 ft) of round ABS Welding Rod
Starter Pack (15 ft) of round LDPE Welding Rod
Starter Pack (15 ft) of round TPO Welding Rod
Starter Pack (15 ft) of round Nylon Welding Rod
Starter Pack (4 ft) of round Polycarbonate Welding Rod
Starter Pack (15 ft) of flat FiberFlex Universal Welding Rod
6027 HT Standard Welding Tip
6031 Tear Drop Airless Welding Tip
200 Watt Ceramic Core Heating Element
2045W Reinforcing Mesh
6124WB Stainless Wire Brush
Starter Pack (15 ft) of round Polyurethane Welding Rod
Starter Pack (15 ft) of round Polypropylene Welding Rod
Starter Pack (15 ft) of round ABS Welding Rod
Starter Pack (15 ft) of round LDPE Welding Rod
Starter Pack (15 ft) of round TPO Welding Rod
Starter Pack (15 ft) of round Nylon Welding Rod
Starter Pack (4 ft) of round Polycarbonate Welding Rod
Starter Pack (15 ft) of flat FiberFlex Universal Welding Rod
How To Repair A Plastic Bumper Crack Repair
Follow the instructions in this Polyvance video showing how to stitch the backside of the bumper with stainless steel screen and groove and fill the front side using FiberFlex filler material
Prime with a flexible primer
3m Plastic Bumper Repair Kit
Once you complete the plastic repair and the surface is sanded smooth, apply an
SEM 39133 flexible primer
automotive-grade flexible primer like SEM 39133 flexible primer (semproducts.com).
Paint the cracked bumper with automotive paint with flex additive
Locate a professional auto body paint supplier that has the capability to load your paint into an aerosol can along with a flex agent. That will allow the paint to flex and not crack off like ordinary touch up paints.
©, 2019 Rick Muscoplat
©, 2019 Rick Muscoplat