rc77More Information; Description: RC-77 is a post-emulsifiable ultra-hh sensitivity fluorescent penetrant desned for inspection of critical parts, turbines blades, assemblies, welds.. Type 1,Description: RC-77 is a level 4, Method B & D non-water washable fluorescent penetrant for inspecting castings, extrusions and similar parts. RC-77 is a versatile, general purpose