When it comes to repairing broken parts that are hard to find, expensive, or just need a minor fix, JB Weld is the go-to epoxy of choice. What started out as a simple method of cold welding in 1969 is now the world’s premier epoxy repair brand, and for good reason – it works.
How It All Started
When Sam and Mary Bonham founded JB Weld in 1969, it was out of necessity. The Bonhams operated a truck repair shop, and Sam needed to repair parts without welding. He worked with a chemist from Texas A&M and together formulated the original “tougher than steel” epoxy and called it JB Weld. The brand has expanded into more areas with many more products, all designed to help make repairs easier and lasting.
To that end, there is some education that comes with JB Weld. Not all bonds are the same. There are many types of glue and epoxy, which ones is best for your parts depends on the material and application involved. There are three types of adhesive cure- evaporative, reactive, and chemical.
How It Works
Evaporative cure is what it sounds like, the moisture from the glue slowly evaporates, leaving the glue to harden, making the bond. This is a mechanical bond, the two parts are held together by the glue itself, they do not become one again. This mechanical bond can be very strong, stronger than the substrate parts themselves. These glues are usually made from natural resins, such as plant and animal tissues.
Types of evaporative glues are Elmer’s glue, wood glue, and solvent-based glue.
Reactive cure adhesives are single component adhesives that cure chemically, this is a 1C class adhesive. You might ask how can a single component cure through a chemical process without a second component, and you would be right. The second component in most cases is air. This is different from evaporative cure, when it is a matter of drying, whereas reactive curing is a chemical reaction with the adhesive air, moisture, heat or radiation. There is another version which is anaerobic, or the absence of air, wherein the chemical reaction occurs when oxygen is not present.
Types of 1C adhesives include silicon, cyanoacrylate (super glue), caulking, and threadlocker.
Two-component adhesives are commonly referred to as 2k or epoxy. JB Weld is an epoxy that consists of an equal ratio mix of resin and hardener. When left unmixed, the two components have a very long shelf life, but when mixed, the reaction begins and the adhesive begins to solidify. There are many types of 2k adhesives, and they are the strongest type of adhesive bond there is. Modern vehicles are actually built using MMA adhesives, the metal is glued together using the MMA adhesive in many instances, including the unibody chassis itself. These adhesives are so strong, the metal itself will tear before it separates from the adhesive.
This is what makes JB Weld so strong, and the product’s tolerance to mixing ratio means that is really hard to screw it up. Most epoxies and 2k adhesives are not tolerant of ratio errors, but JB Weld is simple to meter and mix. The tube versions require you to meter the components out, but most JB Weld adhesives are available in a syringe that has a double plunger, so you get the perfect ratio every time without worry. Their putty sticks also allow for easy measuring as you simply slice off however much you need.
A JB Weld For Every Need
JB Weld makes quite a few products for both automotive and household needs. The great part about it is that the same kit you use to fix the broken ear on your water pump can be used to fix the broken tray in your refrigerator. They offer an entire line of products specifically for wood, including Wood Weld, KwikWood putty, Liquid Epoxy, and Wood Restore Repair Putty. For glass, they have a windshield chip repair system and several glues for bonding plastic and metal to glass, which is a difficult task, especially for rear view mirrors.
JB Weld is more than just a quick-fix product, it is a permanent solution for hard to repair problems. Strip a bolt hole in your engine block or cylinder head? Fill it with JB Weld original, drill and tap. Leaky Gas tank? Clean it, sand it, treat with JB Weld Original or TankWeld, allow to cure and drive on. Every car should have a pack of JB Weld in the glovebox (or in your emergency trunk tool kit, you have one, don’t you?), and a pack in your kitchen drawer.
JB Weld Buyer’s Guide
JB Weld Permanent Repair Solutions
|NCB8265S||JB Weld Original 2 oz.||Our Original Cold-Weld™. Adheres to Metal, Wood, Plastic, Fiberglass, Concrete & More. Sets in 1-2 Hours,Cures in 15-24 Hours.|
|NCB8281||Professional Size Epoxy 10 oz.||Professional Size 283.6 g / (2) 5 OZ. Our Original Cold-Weld™ Steel Reinforced Epoxy. Adheres to Metal, Wood, Plastic, Fiberglass, Concrete & More.|
|NCB8276||KwikWeld™ 2 oz.||Quick-Setting. Steel Reinforced Epoxy. Works on Many Surfaces. Household,Automotive, Plumbing, Marine, Crafts & More. Sets in 6 Minutes.|
|NCB8271||Professional Size Kwik Epoxy 10 oz.||Professional Size 283.6 g / (2) 5 OZ. Quick-Setting, Steel Reinforced Epoxy. Works on Multiple Surfaces. Sets in 6 Minutes.|
|NCB8272||MarineWeld™ 2 oz.||Waterproof When Cured. Use on Marine-craft, Engines, Deck & Hull Accessories. Repairs PVC, Concrete, Fiberglass, Aluminium & More. Cures in 4-6 Hours.|
|NCB8237||PlasticWeld™ 2 oz.||Bonds Instantly with Superior Strength. Works on Rigid or Semi-Flexible Plastics (ABS, PVC, CPVC), Fiberglass & Vinyl Siding. Sets in 20-25 Minutes.|
|NCB8267S||SteelStik™ 2 oz.||Wet or Dry Surfaces. Works on Metal, Wood, Plastic, Concrete & More. Can be Drilled, Sanded, Filed, Tapped, Machined & Painted. Cures in 1 hour. Approved by NSF®.|
|NCB8217||TankWeld™ 1 oz.||Repairs All Metals. Steel Reinforced Epoxy. Approved by NSF®. Cures in 1 hour.|
|NCB8277||WaterWeld™ 2 oz.||Will Set Under Water. Adheres to Multiple Surfaces. Marine Items, Boats, Plumbing, Bathtubs, Showers, Fuel Tanks & Potable Water Tanks. Cures in 1 Hour. Approved by NSF®.|
|NCB8297||HighHeat™ 2 oz.||Continuous Heat to 450º F. Intermittent Heat to 500º F. 3x stronger than similar products. Sets in 1 Hour. Functional Cure in 8 Hours.|
|NCB50132||PlasticWeld™ Epoxy Syringe 25 ml||Quick-Setting. 4400 PSI. Most Plastics, Glass, Composites & Fiberglass. Sets in 5 Minutes. Cures in 1 Hour.|
|NCB50112||ClearWeld™ Epoxy Syringe 25 ml||Our Clearest Weld. Strongest in Class. Use on Windshields, Glass, Most Plastics, Mosaics, Ceramic, Wood & More|
|NCB50101||MinuteWeld™ Epoxy Syringe .85 oz.||Stronger than Super Glues. Multi-Purpose. Multi-Surface. 2850 PSI. Sets in 1 Minute. Cures in 1 Hour|
|NCB50176||KwikWeld™ Epoxy Syringe 25 ml||Quick-Setting. Steel Reinforced Epoxy. Seal-Tight, Reusable Cap. For Auto, Home, Metal, Concrete, Plumbing & More|
|NCB50133||Plastic Bonder™ Syringe Tan 25 ml||OEM Approved Panel Adhesive. Fills Dents, Repairs & Replaces Bonding of Plastics. Works on Carbon Fiber Composites, Coated Metals & More. Dries Tan.|
|NCB50139||Plastic Bonder™ Syringe Black .85 oz.||OEM Approved Panel Adhesive. Fills Dents, Repairs & Replaces Bonding of Plastics. Works on Carbon Fiber Composites, Coated Metals & More. Dries Black.|
JB Weld Specialty Repair Solutions
|NCB2100||Windshield Repair Kit||Patented System. Minimizes Chips & Stars. Repairs up to 1-1⁄4" Diameter Damage. Prevents Spreading. Patented Step-by-Step Solution.|
|NCB2110||TankWeld™ Repair Kit||Fuel & Metal Tank Repair Kit. Petroleum Resistant. Stops Leaks. • No Welding.|
|NCB2120||Radiator Repair Kit||Plastic Tank & Radiator Repair Kit. Works on Plastic & Metal Surfaces. Stops Leaks. No Removal Required.|
|NCB2130||Leather Repair Kit||Repairs Tears, Rips, Cracks & Holes. 3 Easy Steps. No Heat Formula. No Tools Needed.|
|NCB33106||SuperWeld™ Brush-on cap 6 ml||Instant Setting, High Strength. Good For Vinyl, Rubber, Plastic, Leather & Cloth. Brush on Cap. Bonds in Seconds.|
|NCB37901||ExtremeHeat™ Metal paste 3 oz.||Temperature Resistant Metallic Paste. Withstands Heat 2400º F / 1300 ºC. Fill Holes, Cracks in Metal Surfaces; Exhaust Manifolds, Heat Exchangers, Mufflers, Outdoor Grills & Fireplaces.|
JB Weld Gasket Maker Solutions
|NCB32329||Ultimate Black RTV 3 oz.||100% Silicone. High Torque Loads. Temp. Resistant to 500º F. Maximum Oil Resistance. Intake Manifolds, Oil Pans, Timing Gears, Covers & More. Set Time 1 Hour.|
|NCB32327||Ultimate Grey RTV 3 oz.||100% Silicone. For High Torque Loads. For Imported Autos (Honda, Toyota, Nissan, etc.). Non-Corrosive, Low Odor. Set Time 1 hour.|
|NCB31314||Red Hi-Temp RTV 3 oz.||100% Silicone. Heat Resistant up to 650ºF. Form Seals for Oil Pans, Valve Covers, Exhaust Manifolds, Water Pumps & More. Set Time 1 Hour.|
|NCB31316||Blue RTV Sealant 3 oz.||Blue RTV. 100% Silicone. All Purpose. Timing Gear Covers. Transmission & Oil Pans. Set Time 1 Hour.|
|NCB31319||Black Silicone RTV 3 oz.||100% Silicone. Mold and Mildew Resistant. Use for Sealing, Weather. Stripping, Moldings, Interior. Trim, Windows, Windshields, Door Frames & More. Set Time 1 Hour.|
|NCB31310||Clear RTV Sealant 3 oz.||100% Silicone. Waterproof. Resists Mold & Mildew. Will Not Shrink. Windshields, Tubs, Showers, Aquariums & More. Set Time 1 Hour.|
|NCB32509||Ultimate Black RTV 0.5 oz.||100% Silicone. Temperature Resistant to 500º F. Low Odor. Set Time 1 Hour.|
|NCB32507||Water Pump & Thermostat Housing 0.5 oz.||100% Silicone. Oil Resistant. Low Odor. Set Time 1 Hour.|
Check out all the JB Weld 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 products, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.
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.