Will J-B Weld Work On Plastic? (Read This First!)

Will J-B Weld work on plastic? J-B Weld is like any other product since it works well when it comes to bonding specific materials and it is not suitable to be used on others.  When it comes to plastics though, J-B Weld does create a strong bond that is capable of holding up over time provided the product is not required to bend or flex. 

However, the J-B Weld is not designed for some types of plastic. The company is known to make different epoxies which are designed for particular situations that involve a wide variety of plastic types. 

What is a J-B Weld?

J-B Weld refers to a two part epoxy weld. At times referred to as the cold weld, J-B Weld offers an extremely permanent and strong bond.  It can take between 15 to 24 hours for the J-B Weld to fully cure.  

When the J-B Weld is fully cured, you can drill, file, sand or paint it without encountering any problem.  The J-B Weld file has a very tensile strength of 5020 Psi and is capable of withstanding a head of up to 550 degrees Fahrenheit. 

Do you want to know Does J-B Weld Work On Wood? Check this article.

Using the J-B Weld on Plastic

After preparing both surfaces to be bonded, it is now time to prepare J-B Weld.  It is important to note that the original J-B Weld product comes in two different tubes. 

When you mix their contents, it will create the epoxy that will ensure things are well bonded together.  Squeeze equal amounts from every tube onto a paper plate or any other disposable material.  Ensure you squeeze out as much as you will need since there is no other way to put the epoxy back into the tubes. It works the same as toothpaste. 

Mix the substances together using a cotton swab, toothpick or plastic putty knife until they are blended uniformly. Thereafter, apply the mixture to the area you intend to bond on one of the pieces. You can then press all the materials together. 

Ensure you clamp all the bonded items and get another way to ensure the pieces are together since J-B Weld cures. The right method of clamping will vary depending on the item’s shape that is being bonded. When bonding flat items, there is a possibility of a heavy weight sufficing. 

However, in other instances, you can wish to squeeze items in a vice or resort to hold them together using rubber bands. 

welding glue

Preparing the Repair Site 

To successfully use the J-B Weld on plastic, you will have to ensure that both pieces of the project are clean and do not contain any oil, grease or residues.  This is also the case when repairing broken plastic components or when adhering plastics to other surfaces like metal or fiberglass. 

Ensure you thoroughly wipe down the areas you want to bond by using white vinegar or a rubbing alcohol. These two are great when it comes to removing greasy films which might not be evident. 

When you are bonding the two smooth areas together, you will start by roughing them up gently using some sand paper or grit. Thereafter, wipe down the residue using a damp paper towel. 

Related: Want To Know Does Jb Weld Work Stainless Steel?

Cure Time of the J-B Weld

Despite setting in 4-6 hours, the cure time of J-B Weld ranges from 15 to 24 hours. It is highly recommended that you do not attempt to use the items which are bonded for at least 15 hours. In case you are interested in having the bond set faster, consider using kwikweld as it will do wonders despite not being that durable. 

The Original J-B Weld never works well with polypropylene plastics. In most cases, the plastics are identified using the recycling codes that come with them. For example, a triangle having 1, 2 or 4 indicates a particular type of polyethylene. The number 5 in the triangle stands for polypropylene. 

In certain cases, letters can be used instead of triangles and numbers. HDPE, PE, PETE and PET are all polypropylene with PP standing for polypropylene

The codes are usually found at the bottom part of plastic items like laundry detergent or food containers. Polyethylene is normally used for gas containers or water or garden sprayers. Polyethylene is known to be a hard and durable plastic that can be used in car radiator parts. 

Related: Does Gorilla Glue Work On Metal?

Using the J-B Weld WaterWeld or Plastic Weld 

The J-B Weld will offer a PlasticWeld product that is directed towards bonding more plastic types when compared to the original J-B Weld formula.  

Despite the PlasticWeld being available on both the epoxy putty form and two-part liquid epoxy, not the polypropylene plastics or polypropylene will bond. Putty will heal in three hours with the liquid version curing in 1 hour. 

The WaterWeld is another product that is plastic ready that is being offered by the company. It is a perfect product for PVC pipes or circumstances where plastic parts will get wet or are wet. 

Ensure that you properly clean and rough up the PVC surface and thereafter work the two-part putty epoxy together until it is of uniform color. Ensure you properly spread the putty over the regions that are being bonded. 

In case there is a leakage in the pipe, ensure that you press some in the hole by using enough putty around the pipe. This will help in ensuring the plug remains in position after it has been cured. The WaterWeld will set in approximately 15 minutes and will cure within 1 hour.

Related: Does J-B Weld Work On Cast Iron?


We hope you can now answer the question, Will J-B Weld work on plastic? There are lots of works you can do with the J-B Weld.  After investing in the J-B Weld, you will always find yourself using it on different surfaces and metals. J-B Weld will offer you a permanent and strong solution. 

However, there are three major exceptions such as you can never use the J-B Weld on rubber or lead. There are also automobile parts which are not compatible. You will also have to consider the pressure and temperature as well.

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