Hi there, thanks for any help you can give me on what is probably a stupid question. Here's my problem. I came across a leak in my downstairs sink. It appears to be in the drain portion as it only leaks when water is running, and i can put my hand underneath, and those pipes get very wet, very quickly. I watched an online video on fixing this (maybe smart, maybe dumb), and it had me unscrew a gasket near the top of the drain assembly. That unscrewed pretty easily, and there's a plastic piece I took out and cleaned. It was definitely dirty. the video suggested cleaning it, as i did, and then using plumbers putty or silicone on the piece and re-inserting it. Here's the dumb question. They seemed to contradict whether to put the silicone on the top of the plastic, hwere it would meet the higher pipe, or on the bottom side (where it sits in the lower pipe). I'm guessing it should be the top, but would prefer to be 100 percent sure on that. It won't happen until tomorrow as i need to go buy the silicone and should probably just buy a new plastic piece as well. Thanks for any help again, I do appreciate it!