If necessary, remove some of the copper jacket with a file to insure that the copper jacket does not come in contact with the workpiece. Tweezer electrodes can be bent, flattened, notched or slotted to better accommodate an application. To insure proper electrical conductivity, tip of electrodes must be kept clean with a file or sandpaper. It is strongly recommended that you experiment on scrap pieces until you become more familiar with the use of your resistance soldering unit. In general, very small, delicate items will require a lower setting.
Larger items require a higher setting or a longer dwell time.
Trial and error, using test pieces that are the same size and material as the workpiece, is the best method for determining the proper power setting. You can then decide on your preferred setting between these points. Your goal is the fastest setting at which you are comfortable. A low power setting with excessive dwell time tends to allow heat-sinking into areas adjacent to the joint. High settings can produce dwell times so short that you have little measure of control.