Leaking waste arm on bathroom sink

[WahooOne]

I had to remove the trap on my bathroom sink, and now I cannot it get it to not leak. The trap and nuts are metal, while the waste arm is some kind of black plastic. Rather than using a washer, the trap arm has a beveled or tapered end that interfaces directly with the trap. I went ahead and bought an identical replacement metal trap, because the old one was in bad shape. Upon reassembly, I have leakage from the connection between the waste arm and the trap. I have tried tightening to different degrees, disassembling and reassembling several times, and still I have a leak.

The beveled end of the waste arm is slightly scored from previous compression, but it does not appear to be badly damaged. Obviously, if it was a washer I would replace it, but it doesn't look like the waste arm can be replaced without removing the whole vanity.

Am I missing something? Is this a job for teflon tape? Putty? Is there some kind of gasket I can add to the beveled end of the waste arm?

Thanks in advance!
Bryan

 

[havasu]

Unless the Pic is crooked, it looks like the elbow is not pointed straight down. I also see a bunch of crud at the flange. I've found when I synch it up too tight, they always leak. Looser is better. Just a slight snug works best.

 

[WahooOne]

The picture is crooked, sorry it's a real tight little powder room and I'm a big dude.

I wiped off the flange, but was hesitant to get to aggressive with it. Should I try gentle sanding to smooth it? I will try just hand-tightening.

Thanks!!

 

[havasu]

I wouldn't sand it. Maybe Goo Be Gone?

 

[Rickyman]

Use a plastic trap with a plastic waste arm

 

[House Doc]

If it has metal nuts it's probably fairly old. I prefer the white plastic drain pieces. I would go to Home Depot (or any hardware store) and get a complete, new, "P-trap". The package should have everything you need for under $6.00.

 

[WahooOne]

If it has metal nuts it's probably fairly old. I prefer the white plastic drain pieces. I would go to Home Depot (or any hardware store) and get a complete, new, "P-trap". The package should have everything you need for under $6.00.

Thanks, I considered this, but being a novice I went for the like for like option. Doesn't PVC require some kind of additional sealant or dope or something? Or maybe not in the case of pressure fittings?

This is why I avoid plumbing. It always ends with a leak

 

[Jeff Handy]

Plastic p trap on plastic waste arm.

So they can squish together.

Yes, you could lightly sand the bevel of the trap arm with ultra fine grit sandpaper.
Just to smooth any small pits or burrs.

Clean it off first with vinegar and a scotchbrite pad.

If all else fails, you can cheat and add a thin layer of sealant to the bevel edge, such as Permatex #2.
It needs to dry for about a day before running any water down the drain.

It does not ever dry hard like caulk, so if it still leaks it can be taken apart again.

This is a lazy and messy fix, but once in a great while it helps, even though it should really never be needed.

 

[Jeff Handy]

Post a side view pic of the entire black plastic part, it is probably ABS.

How it is attached to the pipe that goes back into the wall?

Let us see how those two are connected.

Are they glued, or is there another coupling farther back towards the wall?

 

[WahooOne]

Post a side view pic of the entire black plastic part, it is probably ABS.

How it is attached to the pipe that goes back into the wall?

Let us see how those two are connected.

Are they glued, or is there another coupling farther back towards the wall?

Thanks Jeff! I’m fine with messy, this is a rental! Please see pics below. I’m not sure how the waste arm is connected but it seems pretty inaccessible.

 

[Jeff Handy]

Wow, I don’t recognize that connection at the wall.
Maybe a reducing bushing inside the tee, then the trap arm is glued directly in?
It almost looks like a slip joint nut, but probably not.

So you already have half of a p trap there, with a captive nut.

If you clean up the bevel, there is no reason that a tubular pvc J bend should not seal nicely to it, unless it is cracked or has deeper gouges somewhere.
Or if you are forcing the J bend too far out of its natural alignment.

Everyone one here will likely ridicule me for even mentioning Permatex #2, but if all else fails.

There are lots of types of Permatex, some are silicone rubber based like RTV, some others will turn hard, so # 2 might be your choice if desperate.

Sometimes just pipe dope will help seal a thin gap, but it can wash out.

Permatex #2 is thin but super sticky.

 

[WahooOne]

Thanks Jeff! This is just the help I needed.

So I went and bought a PVC trap, but the span between the drain and the waste arm was different, so it was a no-go. I cleaned up the flange and installed the replacement brass trap with Permatex#2, as directed. I only hand-tightened at first, and I still had a leak. So I gave it another twist with a wrench and let it cure for 24 hours. And now it's dry as bone!

Thanks so much for talking me through this!

Regards,
Bryan

 

[Jeff Handy]

Hurray!