JB Weld vs Epoxy: Is There Really A Difference?

Over the years, adhesives have evolved to become stronger, easier to apply and give quality results. In this article, we are going to analyze two of the best adhesives there are in the market. That is the JB weld vs epoxy; compare and contrast between them based on their uses and differences.

By the end of this article, you should be able to make an informed decision about which is best for your project. Read on to know more.

What Is JB Weld?

JB weld is a high-temperature resistant adhesive that helps to bond different materials together. Most suitable for materials made of steel, wood, ceramic, iron, PVC, glass, or any of their combination. JB weld is a two-component epoxy introduced to serve as a substitute for the standard traditional welding process.

With a tensile strength as high as 3960 PSI, the JB weld can withstand a temperature of 550o F when covered. It usually set to a hard bond when left overnight and needs about 16 – to 24 hours to fully cure. JB weld is used by many professionals and amateurs alike to achieve a beautiful finish.

What can JB Weld be used for?

JB weld is a versatile bond that is suitable for bonding different surfaces. For example, JB weld can be used to bond the following materials made from;

  • Metal
  • Glass
  • Porcelain
  • Concrete
  • Fiberglass
  • Paper and
  • Marble

Other materials that JB weld also work well on include PVC, ceramic, ABS, wood, and fabric. JB weld is waterproof, acid-resistant and when hardened, it becomes resistant to chemical/petroleum. JB weld was made to be able to resist shock, extreme temperature fluctuations, and vibration.

It is also worth mentioning that JB weld can be exposed to microwave radiation and as such used in a microwave. According to their official Wikipedia page, JB weld is not just an adhesive alone, it is also used as a sealant, filler, plug, and electrical insulator.

Is JB Weld as good as traditional welding?

Also known as the original cold weld, JB weld was initially developed as an effective alternative to traditional welding. It is very effective even in extreme conditions due to its two-parts epoxy system. JB weld helps create one of the strongest bonds once it’s set.

Although JB weld is said to be as strong as steel and a great sealant, it is not externally strong as when a real metal is used. So, it is best if JB weld is treated as an adhesive for holding two pieces of metal together rather than as real welding.

All in all, JB weld is structurally strong and can contend with other strong metals such as aluminum.

What Is Epoxy?

Although the word epoxy might not be new to many people, however, not many people know what it is. Epoxy is a common adhesive polymer made of several subunits of chemical compounds consisting of larger molecules. The inner structure of the polymer is what makes it very strong, elastic, and tough.

Some good examples of polymer include Styrofoam, rubber, and epoxy. 

There are two types of epoxy adhesive or bond found in the market, and they are;

  1. Heat cured or one-part epoxy
  2. Two-part cured epoxies
epoxy feature image

Heat Cured or One Part Epoxy

These types of epoxies require a lot of heat to cure and have several industrial uses. However, due to its high heat requirement, it is not suitable for use in the construction industry. It is used to bond materials like electronic components.

Two-Part Cured Epoxies

It is called two-part cured epoxy because the two components needed for the job come separately. After it is mixed, it needs 24 hours to cure a liquid substance into a hardened material. The two-part epoxies are used in the automotive and manufacturing industry. And unlike its heat-cured counterpart, it can be used in construction projects.

Uses Of Epoxy

The uses of epoxy range from being used in coatings, paints, and adhesives. Epoxy coatings are UV resistant, hard, and abrasion-resistant. As such, it is used to coat metals and materials that need to withstand wear and tear.

Adhesive epoxy is used most commonly in the construction of automobiles, boats, and bicycles among others. Epoxies are also found in electrical systems, industrial tooling, and marine field among others.

Are JB Weld and Epoxy the same?

Well, this is a bit tricky as JB weld is a form of epoxy but stronger than regular standard epoxy.

Differences between JB Weld and Epoxy

Below is the main difference between JB weld and epoxy

JB WeldEpoxy
Needs 24 hours to cureDries very quickly
It’s safe in food materialsIt’s not safe
It is grey in color once curedIt is clear in color


Both JB weld and Epoxy have their functionalities. It all depends on the desired results. We hope this article provides the necessary information needed for making the right choice.