Story of Epoxy || Torch Welding, JB Weld

In 1969, Sam and Mary Bonham ran a machine shop out of Sulphur Springs, TX in which they serviced trucks of all sizes. Like any full-service shop, a good portion of their repair work dealt with traditional torch welding. While this served its purpose it also came with the issue of spatter, deformation, cracks, and slag Inclusions; just to name a few. These are also issues even the best welder will face from time to time.

We’ll come back to our story in a bit. But let's talk a bit about torch welding.

Now generally, torch welding or sometimes referred to as Oxyacetylene welding is a process that relies on the combustion of oxygen and acetylene. When mixed together in correct proportions within a hand-held torch or blowpipe, a relatively hot flame is produced which can reach temperatures of 3200 degrees Celcius or 5792 F. The chemical action of the oxyacetylene flame can be adjusted by changing the ratio of the volume of oxygen to acetylene.

With this form of welding. Three distinct flame settings are used; neutral, oxidizing, and carburizing.

Show flames from Torch Welding

Welding is generally carried out using the neutral flame setting which utilizes a balanced ratio of oxygen and acetylene. The oxidizing flame is created by increasing just the oxygen flow rate while the carburizing flame is achieved by increasing acetylene flow in relation to oxygen flow.

Because steel melts at a temperature above 1,500 deg.C (2732 F), the mixture of oxygen and acetylene is used as it is the only gas combination with enough heat to weld steel. However, other gasses such as propane, hydrogen, and coal gas can be used for joining lower melting point non-ferrous metals, and for brazing and silver soldering.

Oxyacetylene equipment is portable and easy to use. It comprises oxygen and acetylene gasses stored under pressure in steel tanks. The tanks are fitted with regulators and flexible hoses which lead to the blowpipe. Specially designed safety devices such as flame traps are fitted between the hoses and the cylinder regulators. The flame trap prevents flames generated by a 'flashback' from reaching the cylinders; the principal causes of flashbacks are the failure to purge the hoses and overheating of the blowpipe nozzle.

Now onto the downsides, when welding, the operator must wear protective clothing and tinted colored goggles. As the flame is less intense than arc welding and very little UV is emitted, general-purpose tinted goggles provide sufficient protection. Also, it’s probably a good idea to wear protective respiratory equipment since metals can and will vaporize and off-gassing becomes a threat.

Back to the story.

Frustrated with this approach, Sam Bonham knew there was a better way and realized an opportunity to create a product; that could “cold weld” and replace traditional torch welding. Subsequently, he invested his own time and money working with a Texas A&M chemist, and eventually formulated a "tougher than steel" two-part epoxy and named it J-B Weld.

The JB Weld Company was then founded. Initially, Sam and Mary sold their new product out of their car direct to automotive shops and jobbers across Texas. But it wasn’t until the product caught on and would eventually be sold in stores throughout the U.S. and internationally.

In 2008 the company was purchased by a group of private investors. Led by CEO Chip Hanson, and since have expanded the product lines through innovation.

In just a few years' time, JB Weld has broadened the product line to meet the changing needs of its demand, including new adhesives for metal, wood, plastic, and general-purpose use. Some of these innovations include epoxy putty sticks, syringe-based epoxy adhesives, thread lockers, and specialty products that continue to provide the world's strongest bond for most repair projects.

On a personal level, I’ve found myself using epoxy putty sticks with great success for a lot of automotive projects.

At this point, let’s pivot and talk about how two part epoxy works exactly. But for the sake of simplicity, we’re going to keep it pretty high level.

Generally, two part epoxy works by combining an epoxy resin and a hardener in equal amounts.

The term “equal amounts” is important because the reaction between the two happens when ratio is one to one. Technically, the hardener does NOT work as a catalyst, but rather as a component of the reaction. Essentially, it gets consumed in the reaction itself.