Never use Teflon tape on slip nut connections—that’s for threaded pipes, not for these slip-fit joints. Use plumber’s putty only under the sink strainer, not on the trap. And for the love of all that is dry, do not use your phone light while your hands are wet unless you want to find out what a tingly shock feels like. Use a flashlight that sits on the counter.
Also, if you live in a house from the 1970s, the wall pipe might be galvanized steel. That stuff rusts and gets brittle. If it crumbles in your hand, you’ve just started a bigger project. Don’t panic. Call a friend who owns a grinder and has a good sense of humor.
