Skip to content

Know-How Notes: How To Use JB Weld KwikWeld

How To Use JB Weld KwikWeld

JB Weld KwikWeld

JB Weld has tons of products available for specific types of repairs, but the generic epoxies – JB Weld and JB Weld KwikWeld are the main types. This particular article is all about KwikWeld, the fast-setting version of JB Weld epoxy.  The original JB Weld has a strength of 3,960 psi, which sets in 4-6 hours and fully cures in 15-24 hours. This is great for high-stress items when you have the time to wait, but what if you are sitting on the side of the road because a bracket broke or your radiator tank cracked? That is where JB Weld KwikWeld comes in. The strength is lower, KwikWeld is rated for 2,424 psi, but it sets in 6 minutes and fully cures in 4-6 hours, so you can get back on the road much faster without the overnight wait. The other trade-off is temperature; JB Weld KwikWeld is good for up to 300 degrees, while the original version is good for 550 degrees.  

This original Chrysler alternator had some stripped threads, we are going to repair it with JB Weld KwikWeld.
This original Chrysler alternator had some stripped threads, we are going to repair it with JB Weld KwikWeld.

 

Using JB Weld KwikWeld is just like the original version. Surface preparation is everything. A clean surface is absolutely necessary for a strong, secure repair. Be sure to remove all dirt, grease, oil, or paint from the surface. If you have some cleaner available, like brake cleaner, use that. For smooth surface repairs, we would use a little sandpaper (80 grit is good) to rough up smooth surfaces. If you are dealing with cast iron or aluminum, the rough casting should be good as is once cleaned. 

"We

Mixing JB Weld KwikWeld is easy, just make sure that you mix both components in equal portions. It does not have to be perfect, but it needs to be pretty close. We find it easiest to meter out the components next each other in a straight line. This ensures that the components are equal.

We metered out about a pea sized amount of each component onto a piece of cardboard.
We metered out about a pea sized amount of each component onto a piece of cardboard.

 

The amounts should be as close to equal as possible.
The amounts should be as close to equal as possible.

 

Use a mixing tool to blend the components together. In the shop, we use a razor blade, but another good item a plastic scraper blade. Cardboard or scrap wood make a perfect mixing board.

Using a razor blade, we mixed the components until it reached a uniform color. You can use any hard flat object to mix it, even old hotel card keys.
Using a razor blade, we mixed the components until it reached a uniform color. You can use any hard flat object to mix it, even old hotel card keys.

 

Once blended, scoop some up and put it on one side of the broken part, then marry the parts together. Use the mixing tool to clean up the edges where the epoxy squeezed out. Depending on the part, you may want to leave a little extra around the joint to help secure it.

Next, we filled the hole with the epoxy. If the hole is blind, you can fill it as is, if it is a thru-hole, you need to put tape over the backside to keep the epoxy from pouring out.
Next, we filled the hole with the epoxy. If the hole is blind, you can fill it as is, if it is a thru-hole, you need to put tape over the backside to keep the epoxy from pouring out.

 

Let the repair rest for six minutes. If you can clamp it together, that is a good idea. If not, just hold it together. The epoxy will be fully set in four hours at room temperature. If it is below 40 degrees, it will take longer.

We let the epoxy cure for four hours, now it is ready to be drilled.
We let the epoxy cure for four hours, now it is ready to be drilled.

 

Using a 17/64" drill bit, we drilled the hole to match the spec for a 5/16" threaded bolt.
Using a 17/64″ drill bit, we drilled the hole to match the spec for a 5/16″ threaded bolt.

 

"Then

 

All done, now we can reinstall the alternator back onto the engine.
All done, now we can reinstall the alternator back onto the engine.

 

JB Weld KwikWeld is the perfect multi-purpose epoxy for your garage, home, and in your car. In fact, keeping a tube in your car’s toolbox (you do have a proper toolbox in your trunk, right? RIGHT?) is just a good idea.

Check out all the chemical products available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on JB Weld KwikWeld, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.

Jefferson Bryant View All

A life-long gearhead, Jefferson Bryant spends more time in the shop than anywhere else. His career began in the car audio industry as a shop manager, eventually working his way into a position at Rockford Fosgate as a product designer. In 2003, he began writing tech articles for magazines, and has been working as an automotive journalist ever since. His work has been featured in Car Craft, Hot Rod, Rod & Custom, Truckin’, Mopar Muscle, and many more. Jefferson has also written 4 books and produced countless videos. Jefferson operates Red Dirt Rodz, his personal garage studio, where all of his magazine articles and tech videos are produced.

Leave a Reply

Your email address will not be published. Required fields are marked *