Faucet drain pipe leaking between P trap and stub out

[Loneriver]

Hi all,

I installed a new vanity in the bathroom and am replacing the p trap to the new sink. I might be using the wrong terms so please bear with me. The current setup is a stub out made of metal. Attached to that is a black PVC trap arm. The part that angles down to the p trap is flared. This flared end connects connects to the p trap. I assume this is just the common setup.

I was not able to unscrew the black nut from the metal stub out. It wouldn't budge so I just decided to keep the black PVC trap arm on and reuse it.

My new p trap assembly is the thin-walled white PVC style. I hooked that up last night (flared part of the black arm seemed to fit right into the receiving end of the new white p trap. The existing black nut screws easily onto the new white p trap. All seemed to fit well.

This morning I checked and see water had dripped from that joint between the existing black arm and the new white p trap.

Question 1: Is there an issue where the existing black flared end doesn't mate properly with the new white p trap?
Question 2: If that black/white joint shouldn't be made for some reason then I would have to remove the existing stuck black arm and replace it with the white arm the p trap kit came with. How do I get the black arm off? Is it maybe glued on with some type of pipe thread sealer that I have to overcome by force? If not, should I just cut through the black PVC nut to remove it?

Picture of existing setup is attached. I didn't take a picture of the new setup but hopefully my words were clear enough. Thank you all for your help!

-Rob

 

[Terry]

I don't mix p-trap parts for just that reason. I prefer to replace entirely. It may be that you will need to pick up a rubber slip joint washer where it meets the wall stubout. Plastic doesn't seal as well there.

 

[Sponsor]

 

[Loneriver]

Thank you for the quick reply, Terry.

I don't quite understand the recommendation. I've attached a hand sketch to try to be more clear. The leak is not at the wall stubout. It is between the existing horizontal arm (black) and the new p trap (white). Are you suggesting adding a rubber slip joint washer at that transition? If so, I would have to cut off the existing black flare from the end of the arm?

You also said you prefer to replace it all entirely. That is what I'd like to do as well but as I mentioned above, I can't seem to get the black nut to turn where it meets the metal stubout. I'm scared to force it but if that's all I need to do then I will to to remove it. How would you remove it if stuck on the metal stubout? Wrench with force? Just cut it off?

Thanks again for your help. Your site has helped me for many years now!

-Rob

 

[Terry]

The black nut at the galvanized should be removable, and if not, it can be cut off.
Maybe some heat from a hair dryer would help to loosen it.

 

[Loneriver]

Thanks again. I will attempt to remove/cut off the black nut from the galvanized pipe tonight. Can I just screw the new white pvc nut directly on to the galvanized pipe? On some sites I see people screw some type of brass connector (trap adapter?) onto the galvanized which gives new "better" threads for the white pvc nut to attach to? Do both ways work? Thanks again.

 

[Terry]

The PVC nut should thread on, the metal ones sometimes work better, but it's all the same thread.