1. Feeder Glass too cold   1. Feeder Adjust the gob temperature   2. Machine Setup and Operation Plunger is too cold Water in final blow air Excessive oil spray on plunger and neck ring doping or blank doping Final blow air chilling the top of the finish when no internal cooling nozzle is used, or when orifice in blowhead is too large Vacuum applied for too long Take-out tongs cold   2. Machine Setup and Operation Reduce plunger cooling air Blow out the final blow air line Reduce doping oil Use final blow tube with smaller hold Reduce the vacuum time Insulate take-out tongs   3. Mold Equipment Blowhead too shallow or too deep Takeout tongs too tight Neck ring radius too sharp and form not polished 3. Mold Equipment Correct the depth of blowhead Check take-out tongs for clearance Polish and relieve neck ring form