This picture was taken in a 1995 crawlspace this morning. Almost every Schedule 40 PVC fitting was “painted” with this black/grey material. I’ve never come across a black PVC glue or seen this used before. The way it was painted on suggested it was added after the joint was put together. I didn’t find any leaks at the inspection. No other joints showed signs of purple primer, clear glue, or blue glue.
Does anyone know what this black/grey sealer is?