Regular viewers of Weld of The Week seem to enjoy both cutting-edge as well as older technology. This episode showcases an odd old technique. I would like to read your comments if you are familiar with it. 

When I started in the rock bit industry in the ’70s, they were phasing out an old hardfacing technique that applied tungsten carbide to solve ground engaging wear problems. They called it “sweat on.” I always thought it to be a clever trick because you could add a welded wear-resistant coating without adding much thickness to your part. Sweat on was also economical because it uses the base material as the matrix to hold the carbide particles. The trick is to paint sodium silicate on your part in the pattern you wish to apply carbide. Also known as water glass, it is a high-temperature adhesive. Once it dries, excess carbide is removed, and the base metal is melted, allowing carbide to sink and bond to the part. In our video below, we use atomic hydrogen welding, but other processes have been used.

Finally, just to show you that this ancient technology still has applications. We use it to create a hard coating on titanium using boron and plasma.

Watch the video below for more information.