DrBadPlan

First timer here trying to learn on the fly how to install a new drain assembly. Just installed a new sink, tested the drain assembly before attaching the sink to cabinet without any problems, only to have it leak an hour later after it was installed. The water leaks down slowly through the thread of the drain pipe, one drop at at time. Assuming this was because of a bad silicone sealent I took the whole thing apart again. Only now I see that sealant has no bearing on the leak, since the overflow pours into that same space. So my question is what are my options for fixing this leak. The rubber flange was as far as I can tell perfectly flush against the sink opening and on the threads with the plastic washer and nut very tightly( as tight a fit as i could do by hand). This is a PVC drain. Thanks for your help.

Mike

DrBadPlan

Should add that the sink manufacturer says no plumber's putty because it will stain the finish. There is no washer underneath the flange, and I have not added any teflon tape or sealent to the rubber gasket.

locknut

You say that the nut is (only) hand-tight? I would use a wrench and carefully tighten it a bit more.

DrBadPlan

I am right then in thinking the silicone under the flange isn't my problem? I will try the leave it loose enough to leak, tighten until it stops leaking strategy tonight. Should I also teflon tape te PVC threads?

Speedbump

The threads have nothing to do with stopping a leak. They simply put two faces together. If you get some tape in between the two faces that are supposed to make the joint water tight, that in itself could cause a leak.

Teflon tape and pipe dope are used on plumbing fittings that have tapered threads. Silicone is a DIY'er plumbers putty and should really not be used for anything but caulking as far as I am concerned.

bob...

Redwood

I'm guessing that what you are installing is a lav pop-up assy.

First this is not a great place to use a plastic drain assy. and I would suggest getting a chrome plated brass one.

As for the leak...
The leak you see is coming down the threads under the rubber washer (Mack Washer) Apply teflon paste to the threads in the area where the rubber washer lands when tightened. The leak will be gone!

I never use silicone to install a drain on any sink.
Sta-Put Ultra is a non-staining plumbers putty safe for all sinks and surfaces.

DrBadPlan

So teflon paste on the threads at the juncture between mack washer and sink. Any on the washer itself, or the sink itself? Thanks for your help, will hopefully get to try it out tonight.

handyguys

I do not see how teflon tape on the threads will do anything. yes on the plumbers putty. Check out these two videos and the podcast.
Episode #52 - Two Handy Faucet Installations

The non-staining plumbers putty under the flange, the washer and proper tightening of the nut will be all that's required.

__________________
The Handyguys Podcast [url]http://www.handyguyspodcast.com[/url]

DrBadPlan

THanks, this might sound like a stupid question, but I have looked at the instructions a dozen times and it looks like the larger side of the mack washer is against the nut, not the sink, but in these videos it looks the opposite. Is that What I"m doing wrong?

Redwood

Ummm I hate to say it but those video's suck!

In the video they are putting the mack washer on upside down...
Sheesh

Also I said Teflon Paste not tape on the threads where the mack washer lands...

I am so tired of the internet and every idiot out there being able to make a video of how not to do something! Then people assume incorrectly that it is a gospel fact...

Well Handy Guy I just realized that you are the maker of that video..
And I am just an outspoken plumber who has been doing this work for thirty some odd years...
Well have no fear I treat all who give out bad advice on plumbing equally and you are the target of my wrath tonite...
I always bring something to the table...
If you want any of your plumbing videos checked for accuracy before unleashing them on the unsuspecting public you can send them to me for previewing and my comments on corrections to be made...