Hello,
My kitchen sink drain pipe leaks where the black U-shaped (p-trap?) screws onto the straight pipe from the sink. I've read that there is supposed to be a plastic ring or fitting that goes between the two pipes inside, and then plumbers tape on the threads where it screws together. Is that correct, and how exactly do I make sure it goes together correctly? There are several projects such as this where I'm getting a house ready for sale, and doing the work myself, so I'll be asking questions often. Thanks in advance for any help and advice :)