rc77RC-77 is a Level 4, Method B & D non-water washable fluorescent penetrant desned for inspecting castings, extrusions, and similar parts. This versatile penetrant is suitable for use on various materials, including aluminumRC-77 is a Level 4, Method B & D non-water washable fluorescent penetrant desned for inspecting castings, extrusions, and similar parts. This versatile penetrant is suitable for use on various materials, including aluminum