Permatex #2 is one of the best sealants out there. I like it a lot. I've even used it on brake bleeder valves to keep brake fluid from seeping by the threads and ruining nice caliper paint. I plan to use it on the bleeder screws on the calipers I just painted. First calipers ever I've painted for myself. LOL The factories used it on a lot of applications as well. I used to help a guy who lived up the road from me growing up assemble Volkswagen engine case halves with it. They never leaked. It is some badass stuff.