I installed a delta pop up drain assembly (all metal). I'm getting a very small leak at the compression nut dripping down the threads. No leak by the black gasket. I have it pretty darn tight and don't want to tighten anymore. Please tell me your methods for installing this type of drain. Do you use plumbers putty, silicon, tape, thread sealant? Where do you tape? Plumbers seem to have multiple methods in how to install the pop up drain assembly. I just want to get this leak to stop.

I did use silicon under the drain part that shows in the sink. I didn't tape that part though to the tail part. I might not have let the silicon cure enough as I was eager to test my drain if it was leak free. Thank you.

 

Try to not disturb the drain flange where you put the silicone, that's only to keep water in the bowl and not to prevent leaks below.
Loosen the nut and large basin washer as far down as you can get them, you need to expose as many threads as possible.
Dry all parts completely, use a blower or hair dryer if needed.
Apply Teflon paste to the male threads of the pop up body. The paste is thick and consistent and will seal any leaks between the washer and threads.
Push the washer back up and tighten the nut hand tight plus about a 1/2 turn.

It's common for the basin washer to leak and you probably did nothing wrong.

 

I ended up following some of your advice. I took out the drain flange and removed the silicon and used putty. Then taped the drain flange threads to the tail pipe. I also taped the threads near the cone washer. No leak. However, I do notice the drain flange I'm using looks a bitter different than others I have seen in pictures and videos. The pop up drain assembly is made by delta. I notice the drain flange has 4 holes on the sides and then below that are the threads to screw into the tail. So when water goes down the flange it not only goes down the tail pipe (where it should go) but also can trickle down those 4 side holes. See the picture attached of the exact flange I'm using. So if the water (or gunk) gets through those 4 holes it just sits there above the black cone washer? That doesn't make sense to me. Please help this beginner understand. Also, the plumbers putty gives off an odor every time I run water. I can actually smell the putty. Is that normal and will go away with time? The water is making contact with some putty that is near those 4 holes. I cleared out the four holes so no putty is blocking it but some is around the top edge. Thanks for your help.

 

Here is the picture. It didn't attach to my last thread.

 

Putty and teflon paste...

read here... Ive been doing these 30 plus years...

http://www.doityourself.com/forum/to...pe-washer.html