How Long Does JB Weld Last?

Written By: Liam Bryant

When looking up how to weld without a welder, using an adhesive such as epoxy is one of the most common ways to work around this problem. JB Weld is one of the most common metal epoxies out there, beloved by DIYers for its strength and durability.

One reason why JB Weld is so popular is that it lasts for ages. It can sit in tubes for up to three years. Once you use it for your repair, the repair will hold on for many years and even forever if you don’t expose it to wear and tear.

Here is everything you need to know about this excellent solution for DIY projects.

What Is A JB Weld?

First, you need to know what a JB Weld is. JB Weld is an epoxy, or a type of adhesive, used in extra-strength applications such as auto body shops, carpentry, and metalworking. It uses a two-part system to deliver lasting repairs with durable properties, including heat resistance.

According to the official JB Weld website, this is the original “cold welding” product, as it is as strong as welding without requiring the heat of torches. However, you shouldn’t confuse it with actual cold welding, which uses pressure to weld parts together.

jb weld

Does JB Weld Work?

JB Weld promises to deliver results that are as tough as traditional welding, but does it actually deliver? JB Weld does work and has great results when it comes to tough projects. However, it doesn’t work in all circumstances, and sometimes you must stick to traditional welding.

Here are a few questions you can ask yourself to determine if JB Weld will work for the job you are doing.

What material am I working with?

JB Weld works with a variety of materials, including fiberglass, ceramics, glass, wood, and even metal. Other adhesives are better for canvas, plastics, and rubber. Traditional welding will always be stronger if you join metal and metal.

What type of job am I doing?

If you’re trying to join two surfaces together, arc welding will always be stronger than JB Weld. However, JB Weld has more applications than welding. It can join two surfaces, fill in holes, and connect two different materials.

How strong do I need the bond to be?

Arc welding will create a stronger bond when joining two metals—that is true. However, sometimes you don’t need the strength that a welding bond gives. If you’re doing a surface repair, JB Weld is more than durable enough. 

JB weld

How Long Does JB Weld Last in the Packet?

Let’s say you’ve got a packet of JB Weld lying around and want to use it for a project. Can you use the old JB Weld, or do you have to go buy a new pack? 

There is no definitive answer to this question. One part of the JB Weld website says it can last in the package, unopened, for three years, while another page says it can last for up to 25 years.

A good rule of thumb is that if you close the tube carefully in between each use, it can last for several years and almost indefinitely.

How Long Does It Take to Cure and Harden?

Once you apply JB Weld, you need to give it time to cure and harden. It usually takes 15–24 hours to reach the right strength. 

Cured JB Weld is extremely strong as long as you follow the right steps to cure it. These include:

  • Mixing it at a 1:1 ratio
  • Keeping it at room temperature and regular humidity
  • Leaving a test batch out so you can see when it dries

Be careful not to move your project until the JB Weld hardens completely so you don’t affect its strength.

How Long Does It Last After Use?

Once you use JB Weld to create a bond, that bond will last for many years. Some data says you can expect the bond to hold for seven years, while others say the bond lasts indefinitely. As long as you followed the instructions when applying JB Weld, it’s safe to say it will last for a while.

How Strong Is JB Weld?

Don’t compare JB Weld to your regular glue. It is an extremely strong adhesive. According to statistics, it measures a tensile strength of 5020 psi, which means it can withstand extremely high tension. It can withstand high heat, cold, and even pressure.

Final Thoughts

If you can’t use arc welding or don’t want to use heat, JB Weld is one of your strongest alternatives for bonding materials. This epoxy can last for many years under different temperature extremes and plenty of tension. JB Weld will be a reliable support if you follow package instructions and let it cure until it hardens.