Plastic Bonder vs. Plastic Weld: What’s The Difference?
The plastic weld is used to join two pieces of plastic together, while a plastic bonder is used to attach one piece of plastic to another surface. Plastic welds are typically stronger than plastic bonders because they actually melt the plastic together. Plastic bonders are usually less expensive than plastic welds and can be used on a wider variety of plastics.
- Plastic Bonder vs. Plastic Weld: Specs & Uses
- My Hands-on Test of Plastic Bonder (J-B Weld 50139 Plastic Bonder)
- Plastic Weld (J-B Weld 8237 PlasticWeld) – Repairing Tines in a Dishwasher Rack
Plastic Bonder vs. Plastic Weld: Specs & Uses
⏰Setting Time
Plastic Bonder: 15 minutes
Plastic Weld: 4-5 minutes
🆚Substrates
Plastic Bonder: Most plastics, metals, and concrete
Plastic Weld: Polyethylene (PE), polypropylene (PP), and other difficult plastics
🛠️Common Uses
Plastic Bonder can be used to repair sun-induced cracks on a car dashboard: suitable for bonding plastic speaker covers to rear plastic door panels; and sealing hairline cracks in TPU outsoles, such as those found in ice skates; attaches plastic side skirts and splitters to the lower body of a car.
Plastic Weld can be used to repair PVC pipes, broken plastic items such as eyeglass frames, plastic planters, plastic door handles, and broken hinges on lids of plastic waste containers; can be painted over
Technical Info
If you are looking for a general-purpose adhesive that is easy to use, then Plastic Bonder is a good choice. If you need to bond difficult plastics and you want the strongest possible bond, then Plastic Weld is a better option.
My Hands-on Test of Plastic Bonder (J-B Weld 50139 Plastic Bonder)
JB Weld Plastic Bonder Temperature Range
-40°F to 200°F
✅Pros: Best Adhesive to Bond Metal to Plastic
I have tried other adhesives, but none have been able to match the reliability of JB Weld’s products. What I admire most about the company is how direct and honest they are.
For example, when I needed to re-attach a 1/2 inch wide, 2/16″ thick trim piece that keeps the bumper flush with the fender, JB Weld’s plastic bonder did the job perfectly. It was hard as a rock after letting it dry for 6+ hours, and even though it wasn’t flexible at all, it did what it was supposed to do.
Hold a Pair of Sensors
Recently, I had a project that required bonding a metal bracket to the plastic of an automotive grille to hold a pair of sensors. I needed a fairly fast-setting adhesive that could precisely position the sensors, blend in with the grille, and hold them extremely securely. That’s when I turned to JB Weld’s plastic bonder.
To ensure the sensors were held in perfect positioning, I first used a “dot” of JB Weldto immediately hold the two mounts in their exact positions. Then, after a couple of minutes, I used the plastic bonder to add the fillets and smooth seams I wanted to guarantee strength. It worked excellently, and the mounts looked fantastic, even up close. The sensors were held very stable, both rigidly held in perfect positioning, as required.
Read More: best epoxy for plastic gas tank repair
Versatility
JB Weld’s plastic bonder has helped me fix many things that I thought were beyond repair. For example, when the part of the light that attaches to my e-bike broke off, I attached the light with duct tape – Alien tape (See alien tape vs gorilla tape) 
as a temporary solution until I replaced it. Unfortunately, I couldn’t find the same light, and all other options would’ve required rewiring. I tried other glues that didn’t hold up and was convinced I would be stuck with ugly duct tape on my bike permanently. So, I was thrilled when I tried JB Weld’s plastic bonder, and after applying and letting it sit for 12 hours, I was riding again! The light is still attached, even after a fairly bumpy ride. It was pretty messy to mix, but it worked, and I’m happy.
Will Fiberglass Bond to Plastic?
JB weld Plastic Bonder “wets out” or saturates fiberglass very well. Shouldn’t be an issue there. I have used it in conjunction with fiberglass cloth to repair cracks in the plastic tanks on the radiator of a car with great success.
❌Cons
One important thing to note is that you need to prep and clean the surface thoroughly before using JB Weld’s plastic bonder. I use Windex, an alcohol-based cleaner, to clean the surface and then use a green Scotch Brite to rough it up. That’s how I was able to use JB Weld’s plastic bonder to adhere the bumper guides directly to the bumper when my front bumper guide mounts were completely broken off. I already scraped my bumper once exiting a driveway with no issues. It was a major win in my book for the price!
💬 FAQ: J-B Weld 50139 Plastic Bonder
Q: Can this product be used to fix a gas can with a damaged seam, or will the gas corrode it?
A: I would recommend getting a new gas can or considering purchasing additional insurance.
Q: What is the difference between setting time and full cure time?
A: Setting time and cure time are not the same. Setting time is the amount of time it takes for a material to become solid, while cure time is the amount of time it takes for a material to reach its maximum strength. For example, conventional concrete will go through the initial set in about 2 to 3 hours, depending on the mix, but curing is the process of preventing fast moisture loss in the concrete, and properly done takes at least 7 days and often longer. Similarly, for epoxy, the set time is the amount of time it takes for the epoxy to become solid, while the cure time is the amount of time it takes for the epoxy to reach its maximum strength.
Q: Would this bonding agent be effective for repairing a thin sun-induced crack on a dashboard?
A: Yes, absolutely. I have used it on my 2003 Pontiac Grand Am dashboard, and it worked perfectly. After clamping it for 15 minutes, it was solid, and after letting it set overnight, it was absolutely perfect.
Q: Is this Plastic Bonder suitable for bonding a plastic speaker cover to a rear plastic door panel?
A: Yes, it is great for bonding two different types of plastic, and I’ve had success bonding two different plastic compositions together. Just follow the instructions, and it should work.
Q: Can this Plastic Bonder create a strong enough bond to attach a plastic tracker to a metal tool?
A: Yes, this Plastic Bonder is excellent for creating strong bonds. I used it to reattach a microwave door handle, and it blended in perfectly.
Q: Is this adhesive suitable for repairing cracked plaster walls?
A: While it is intended for repairing ABS plastic, I don’t recommend it for repairing plaster. Joint compound and joint tape are likely better solutions, depending on where the plaster is cracked.
Q: Is this Plastic Bonder appropriate for sealing a hairline crack in the tpu outsole of an ice skate? And will it be waterproof once cured?
A: Yes, this is a great product for repairing the crack, and it is definitely waterproof once cured.
Q: Can I apply this Plastic Bonder directly onto nice car paint to fill a gap for a small bump on the front of my fairly new car?
A: I haven’t tried it on a bumper yet, but I have used it successfully on buckets to retain water.
Q: Is this Plastic Bonder self-leveling?
A: Yes, this Plastic Bonder Body Panel Adhesive is self-leveling for a few minutes after mixing. It dries to a glossy surface and cures to a durable, strong plastic.
Q: Will this Plastic Bonder work to repair a plastic leader hose connector on a water hose reel cart?
A: It didn’t work for me, so I doubt it.
Q: Can this bonding agent be used to attach side skirts and splitters to the lower body of a car instead of riveting or screwing?
A: Yes, it is a strong bonding material and should work well if both items are plastic. Just follow the instructions.
Q: Will this Plastic Bonder be effective for bonding a black plastic cattle feed trough?
A: Yes, it worked for my Jeep’s bumper, and it is still holding up great.
Q: Can this glue withstand hard impacts and weight, such as bonding a broken lock on a trekking stick?
A: While I’m not sure if it can withstand that type of pressure, I successfully used it to repair a large chip in my bowling ball four months ago, and it has held up well.
Q: Can this Plastic Bonder be used to attach a plywood boat seat to cover an aluminum sheet metal boat seat?
A: I wouldn’t recommend it since plywood can delaminate. The JB Weld bond would be stronger than the bonded layers of the plywood, and it would likely come apart as soon as you shift your weight. A combination of JB Weld and screws from the aluminum support into the plywood would be more secure.
Q: Is there a static mixer that is compatible with this tube?
A: I’m not sure, as I used the product as recommended by the manufacturer.
Q: Will this Plastic Bonder bond two sheets of ethylene tetrafluoroethylene (ETFE) together?
A: It has good fastening properties, so I would give it a try. It will depend on the sheer strength you need, but JB Weld should not attack or dissolve this substrate.
Q: Is this Plastic Bonder suitable for repairing a chipped headlight on my car?
A: No, it wouldn’t be a good solution since it dries opaque black.
Q: Can this adhesive be used to bond a plastic lens back onto the tail light housing of my vehicle?
A: Yes, it should work well. It bonds metal to plastic, so just be sure to properly prep the surfaces to be bonded.
Q: Does this Plastic Bonder dry hard or remain pliable?
A: When mixed correctly, it will dry hard.
Q: Can this Plastic Bonder bond to the plastic of a key ignition lock?
A: Yes, it bonds to plastic really well. Roughening up the plastic before bonding and using stainless steel mesh to reinforce structural areas can also help improve the bond.
Q: Can this Plastic Bonder replace Bondo for auto scratches?
A: No, it is too thick to fill in fine scratches, so it would not be a good replacement for Bondo. I’ve written an article about Bondo Vs. JB Weld. Feel free to read it.
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Plastic Weld (J-B Weld 8237 PlasticWeld) – Repairing Tines in a Dishwasher Rack
✅Pros: Best Glue for Bonding Plastic to Plastic
Besides, It was a good time to test it against the plastic bonder. So I decided to give JB plastic weld a try. I mixed it up, put it on, sanded it down the next day, and hit it with a little spray paint. You can hardly tell there was ever any damage. It was crazy easy!
Repaired a slight damage on the rear lift gate handle
I also repaired a slight damage on the rear lift gate handle cover of my used vehicle. I had tried to get a replacement, but they were extremely pricey. I figured I would try J-B plastic weld instead, and it worked great! It is functional and secure. The adhesion is excellent, and the coverage is superb. It can even be sanded if I wish to make it even better. I am no longer worried about the panel falling off or being broken open to access the door mechanism.
This putty did a great job of bonding to the broken edges and being malleable enough to replace the broken part. All I needed to do was sand it down and drill a hole.
Repaired Junction Boxes
I had two old and failed junction boxes 
that were mortared into the side of the brick on my house. In one instance, a rusty screw head broke off and could not be removed without drilling it out. In another instance, I noticed the screw hole had broken off entirely as I attempted to change out a light fixture.
I decided to use J-B Weld plastic repair putty and envelop a plastic mortar anchor and then putty it into the proper position within the failed junction boxes to then later screw in screws to hold a new GFCI outlet and light fixture. I may have waited longer than even needed, but I decided to let the putty cure overnight. The next day, I screwed in the screws that were held in place by the anchors epoxied to the junction boxes. The putty was solid and held the light fixture and a new GFCI outlet securely in place.
💬 FAQ: J-B Weld 8237 PlasticWeld
Q: Can the PVC pipe with a 1-inch slit be sealed using the plastic weld? I need it to hold 75 lbs of water pressure and would like to put a rubber patch and 2 pipe clamps over it.
A: It would be better to avoid sealing the pipe using the plastic weld since creating new joints may result in leaks. It is recommended to cut out the damaged portion and replace it with a new PVC pipe for a more reliable fix.
Q: Is this item suitable for fixing a broken plastic eyeglass frame on the temple leg?
A: Unfortunately, after working as an optician for over 30 years, I have not found any solution other than using a 2-part epoxy or resin, which may only work temporarily and can be messy. It is best to visit your local optician for assistance. They may have discontinued frames that can be used or can hand-edge the lenses to fit a close match. Scratch removers for eyeglass lenses are also not effective. I hope this information helps. By the way, you can check out my website glassescontacts.com, or my Facebook page for more information.
Q: Can the plastic weld be used multiple times or is it for one-time use only?
A: Yes, the plastic weld can be used multiple times. I purchased a tube from Amazon in January 2018 and used about half of it. In February 2021, I used the remaining amount to fill in some drill holes in the wood furniture I was repairing. To keep it fresh, it is recommended to keep the outer foil on the remaining amount, wrap it in plastic wrap, and put it back in the plastic tube with the cap secured.
Q: Is it possible to fill in gaps using the plastic weld? I have some plastic planters with a few cracks at the top edge, and the cracks are about 3 inches long with a few small gaps.
A: Yes, it is possible to fill in gaps using the plastic weld as long as the existing surface is molded correctly to the shape of the filler.
Q: Can the plastic weld be used to repair a cracked plastic air valve on a big inflatable boat tube?
A: It would depend on the location of the repair. The weld material is designed to be rigid once cured. If the repair area remains on a one-dimensional plane throughout its function, then the repair would probably hold. However, if the repair area is subject to repeated flexing on one or more axes, it may not be able to withstand the pressure. Best of luck with your repair.
Q: What is the recommended way to clean up the plastic weld after use with water, etc.?
A: Regular hand soap and water should be sufficient to clean up the plastic weld after use.
Q: Can the plastic weld be used to repair a broken plastic boat windshield or a broken plastic door handle?
A: It may work for repairing a broken plastic door handle, but it cannot be guaranteed to repair a broken plastic boat windshield invisibly.
Q: I have a silicone mold that I use in the oven, and it has a crack. Can I use the plastic weld to repair it for reuse in the oven at 250-275 degrees?
A: It is not recommended to use the plastic weld on any surface that comes in contact with food as it contains chemicals that may leach out even with heat exposure. For silicone, food-grade silicone is the best option, and it can be used to patch the crack. Another possible option (although not recommended) is to use aquarium-safe silicone to patch the crack. Any silicone should be able to withstand high temperatures, and most things will not stick to silicone except for silicone. Food-grade silicone can be used to make custom trays, duplicate trays, or even line multiple trays depending on usage.
Q: Can the plastic weld be used to fix a large crack in a dog crate?
A: Clear Weld 2-part epoxy #50112 would be a better option for repairing a large crack on a dog crate. The surface should be lightly sanded with sandpaper or a nail file board, and the area should be cleaned with rubbing alcohol. Rubber bands or clips can be used to hold the repair tight as it cures, and it is recommended to let it set overnight for the best results.
Q: Will the plastic weld hold in a freezer for a shelf?
A: It is not recommended to use the plastic weld for a shelf, especially due to the weight that will be placed on it.
Q: Does the plastic weld hold up to gasoline?
A: the plastic weld can hold up to gasoline. Sanding down the surface, cleaning it with lacquer thinner, and allowing it to cure for at least 24 hours are recommended before use.
Q: Can the plastic weld be used to fix plastic chairs?
A: the plastic weld can work and bond to most plastics. It can be used to repair a broken hinge on a lid of a plastic waste container, for example.
Q: Can the plastic weld be painted on after it hardens?
A: the plastic weld can be painted on after it has cured.
Q: Can the plastic weld be used to fix a crack or hole in a car bumper?
A: the plastic weld may not be the best option for fixing a crack or hole in a car bumper. It is recommended to use a plastic welding kit or a two-part epoxy specifically designed for automotive use. These products can provide a stronger and more durable bond that can withstand the stress and strain of driving.
I’m Ronald Stevens, a Mechanical Engineer obsessed with adhesives, glue, and all things sticky! My passion began in childhood when I’d always be the one playing with glue during arts and crafts. And I’d spend hours researching and experimenting. Happy reading, and remember: stick with the best, and you’ll never be stuck in a mess!
Feel free to contact me and join our discussion:
What is the JB Weld Plastic Bonder's full cure time?
The full cure time of JB Weld Plastic Bonder is up to 15 hours. The mixture sets in 4-6 hours and can be drilled, ground, tapped, machined, sanded, and painted when cured.