Cold front is a harmless, odourless, non-toxic putty that stops heat travelling through metal while welding, brazing, soldering etc., saving you time in two ways. Firstly, it concentrates the heat in your working area, saving warm up time, and secondly, it protects surrounding glass, rubber, vinyl and plastic from heat damage, making it unnecessary to dismantle before welding. It also prevents warpage when applying heat to areas of thin gauge metal. Works like magic. 414 ml.