Because many water channels are very small, a little mineral scale can have a significant impact. Also, water cooled cables tend to fray and release small pieces of wire into the cooling system. Operators have the best opportunity to spot these problems before they cause a machine shutdown. Excess heat should always be reported and investigated. When properly set up resistance welding machines should produce no flash.
Weld flash is a fire hazard and requires that any flammable substances be properly protected.
Weld flash is also an abrasive. Moving parts should be protected from exposure to weld flash whenever possible. If allowed to accumulate across platen and fixture insulation, flash will cause a slow burning, gradually extending back to inaccessible areas. Eventually this will begin to interfere with the welding process, and a major repair and cleaning are called for. Transformers should also be protected from weld flash.