Chemtools weld crack kit and fault finder system is specially formulated for weld seam quality assurance. Detects microscopic cracks and flaws on the surface of metals, plastics and ceramics revealing them as red marks on a white background. A simple 5 step detection procedure. Chemtools weld penetrant is formulated to seep into any micro cracks present in a weld seam. This product is also referred to Dye Penetrant Inspection (DPI) or liquid Penetrant Inspection (LPI); it is as an inspection method to locate surface-breaking defects in all non-porous materials including plastics, ceramics and most metals. Chemtools weld developer consists of a white powder suspended in solvents; this product is designed to pull the entrapped penetrant to the surface by capillary action.