Guidelines for Making Resistance Welds

  1. Use only welding electrodes of the specified type and shape and make sure they are clean when installed. Do not use electrodes of unknown material. Use straight electrodes when possible. Only use offset electrodes when there’s nothing else that will do the job.
  2. Always check the location of the deflector tubes (water tube inside the electrode) when installing electrodes, see that they go well up into the electrode cooling recesses.
  3. Always check the flow of cooling water to the electrodes, transformer, and SCR contractors before welding.
  4. Always use the correct size hose to supply cooling water to these component parts. When hoses must be removed from the water connections, look into the ends before reassembling to ensure against loose material that may partially block the hose.
  5. When an electrode holder will not be used for several days, remove the welding electrodes to prevent them from “freezing” into the holder due to corrosion.
  6. Never use Teflon tape to prevent water leakage around electrodes. If the weld taper will no longer seal, it is time to replace the electrodes or holder.
  7. Use fine emery cloth to dress welding electrodes. If the electrodes have deteriorated to a point where such methods are inadequate remove them for machine dressing. If you instruct a mechanic on how to machine dress electrodes, tell him to remove a minimum amount of metal. Resistance welding electrodes are made from valuable alloys that should not be wasted by removing more metal than absolutely essential. The use of files is not recommended for dressing electrodes. Certain contour files designed for this purpose may be used with discretion.
  8. NEVER STRIKE A CONDUCTING PART OF YOUR EQUIPMENT WITH A STEEL HAMMER. If there is a need for a blow to move a tip holder or arm, use a rubber, rawhide or plastic mallet, never a steel hammer.
  9. If a leak develops or exists in any part of the cooling system for your equipment including the water hose connections, correct it or it immediately.
  10. See that all mechanical connections in the secondary circuit of your welders are kept tight and clean. Keep an eye out for damaged shunts and cables.
  11. Always perform maintenance regularly as scheduled. This includes cleaning and lubrication.
  12. Keep in mind that sparks in resistance welding are not good, and are a sign of borderline balance between current and pressure. Among the items to check when frequent sparking or expulsion of metal from the joint is encountered are the squeeze and hold time. Material conditions is also a factor while adequate pressure between the tips is essential to freedom from sparking.
  13. As much as possible do NOT extend metal into the throat of your machine. Remember that ferrous metals react in the throat of the machine secondary, increasing their reactance which will reduce the available amperage necessary to produce the weld.