Porsche This general-purpose Loctite RTV Black silicone glue sealant bonds, repairs, seals, mends, and secures glass, metal, plastics, fabric, weatherstripping, and vinyl tops. Loctite RTV Black can also be used to repair electrical wiring, and may be applied to either horizontal or vertical surfaces. This RTV sealant is waterproof and remains flexible from -80 to 450 degrees F. It resists oil, weather, vibration, and grease.