Common TIG Welding Issues, Non-Starts - Back To Welding Basics Part 2

Common welding issues Part 2. TIG Welding: Hard StartingThe TIG work clamp should always be placed directly on the work and as close to the weld as possible to prevent arc starting issues. People want to argue this point sometimes as they’ve always welded with the work clamp connected to a table leg, in other processes but considering the random path the HF arc is subjected to, and the low amperage that is being used to start the arc (10 amps or less usually at start amperage), faulty work clamp placement really is major cause of unreliable arc starts. (If the arc will start at higher amperages but not at lower ones, consider this a primary point of investigation.) Not only should the work clamp be placed on the metal being welded, it has to be making good contact to the metal. This means grinding the surface to expose the fresh, unpainted, unrusted, and de-oxidized metal beneath. In aluminum, don’t expect the shiny surface of aluminum to be a naturally good conductor. It is not. What you see is a form of oxidation. Steel may be deceiving as well. Flap disks can appear to polish the metal to a shine, but many times only the mill scale has been polished and the real metal lies underneath. In any cause surface contamination can give the HF arc an excuse to not start properly. Furthermore, when a clamp is connected to a rusty or painted table leg, routing the flow of electrons through it, to a dirty metal table top, to the backside of an oxidized plate of metal with little direct contact to the unoxidized part of the metal is a challenging task for any welding equipment. Also you should take into account the condition of the work clamp as it is often, neglected, and abused. When welding the clamp can become warm. This is a sign of resistance to the flow of electricity. Now, a certain amount is to be expected, especially welding at higher amperages, but if a hot spot is noticed, or sparks are seen from it, or it or the cable begins to smoke due to the heat, something is wrong. Corrosion or oxidation of the work clamp itself may become a barrier to a good current path. Even new welding machines can experience this as cables and connections can become loose or lightly oxidized or corroded in shipping.Everlast Generators, your complete welding resource.Learn more on our welding forum