Expando is the one and done till a mod option. If you clean it with contact cleaner and a wire brush,let it sit and dry for a min , then put the expando on, it may never come apart but it also won't leak... I also will do a thin coat of blue monster pipe dope, then 3 wraps of blue monster tape, then more dope over the tape. We have jobs 10+ years old with that method and no leaks. 10+ years ago it might not have been blue monster but that's what we've used for as far back as I can remember
