Other Forms Of Welding You've Never Heard Of. Part 1
Everyone knows that there are three basic forms of welding accessible to most general welders, professional and hobbyists alike. They are TIG (GTAW), MIG (GMAW) and Stick (SMAW). However there are other forms of welding that are used every day throughout the industry, but you probably never heard of them. Let’s look at a few of the most interesting ones. One of the ones that you may have seen and didn't know about is Thermite Welding. If you've ever seen one of the “Terminator” movies or series, thermite is what they used to dispose of the “bodies” of the terminators. This isn’t a science fiction process though. It is used everyday to join rail road tracks together. If you've ever crossed a railroad track and seen them working on the track, then thermite welding probably was being done. It’s an exothermic reaction that uses aluminum as a reducing agent and iron oxide mixed together. This type of railroad welding employs a detailed process to perform properly. Preheating, and chemical reaction time and joint design etc are all critical to making a satisfactory weld. The thermite compound though highly reactive is very stable, and can only be ignited at 2800 degrees F. When it ignites, it heats up to 4500 degrees F, much higher than the melting point of steel. A mold is placed around the track after it is thoroughly prepped and cleaned for the reaction to take place. It is cooled carefully and the area is dressed so that the rail will be smooth.