Use of Teflon tape on plastic cone washer, sink drain

[blockisle9]

I was told that this is a no no!
In the past I always had issues with leaks when repairing plastic kitchen and bath drains. I always replace all the parts so everything is new.
Long story short, I now wrap Teflon tape around the threads that the slip nut screws on to, I also wrap some tape around the plastic cone shaped washer before tightening every thing up.
Is there any disadvantage in doing this?
I know it should not be needed but it helps me avoid disassembly and reassembly multiple times.
Thank You

 

[johnjh2o]

There is no reason to use T-tape on slip nuts. I have never used T-tape on slip joints in over 50 years. Seems like a waste of effort and tape to me.

John

 

[phishfood]

The seal on a slip joint is not obtained at the threads, it is at the conical washer. I have found over the years that using a coating of pipe dope on the beveled sealing surface reduces leaks from uncommon down to almost unheard of.

 

[stevemachine]

Yeah I agree with dope. I've had traps leak after you pull them apart and re assemble. It's not a permanent solution obviously but it least it works. I don't think there's anything wrong if you wanna use tape, its not needed but its not gonna wreck anything, tape does make stuff look kinda sloppy on drainage. If anything dope it up I'd say

 

[actionjw253]

Teflon tape is absolutely not needed on a kitchen or bathroom sink trap. When i go to a house and see teflon tape i laugh at the person who did it before me. Put pipe dope around slip washers and if youre worried about a leak you already cross threaded the trap nuts or stripped it