What is the back-step method? If you have ever TIG (Tungsten Inert Gas) welded thin gauge material, you have no doubt warped or distorted a piece or two. There is actually a pretty simple way of preventing this. If you are able to, use a chill block or heat sink and put it behind the pieces.
But sometimes, you’re just not able to do it that way. In circumstances like these, we suggest that you try the back-step method. Keep in mind that you can do this with any process, however we mainly recommend it with TIG. It’s a very simple process. For the sake of instruction, I will explain this from the perspective of a right handed welder. If you are left handed, reverse the directions.
The Back-Step Method
Typically a joint is welded from right to left and the heat is pushed along the joint. This causes the heat to continually build up higher and higher throughout the weldment. With the back-step method, the first thing we want to do is place several tacks throughout the joint to prevent the heat from causing a separation of the plates. Then we will start off at about 1-2 inches from the end of the joint and weld right to left, once the weld is terminated, we will move 1-2 inches to the right of the initial start point of the first weld and weld until we tie-in to the start of the first weld. The process will be repeated throughout the entire joint until the weldment is complete. By doing this method, the heat is distributed and the heat in the material doesn’t build up and cause distortion.
A quick little instructional blog piece for you, but one that will be very useful for those getting frustrated with warped plates. Make sure to stay tuned for regular updates and more tips and tricks!