sink flange/drain assembly install

[spot-the-dalmation]

Hello:

I am installng a new one piece bathroom sink (marble/fakemarble type). I purchased a pop-up drain assembly by plumbcraft to install in the sink. I have a couple questions to be sure I get this right:

The flange came with a rubber washer. Most DIY instructions I have seen says to either use silicon sealant under the flange (for marble type sinks) or a strip of plumbers putty. My question is can I use this washer instead? If so, should I coat it with silicon on both sides or is the rubber enough? If not----why? It seems the rubber would create a much better seal. But---that is why I am asking---I have no idea.

On the underside of the sink, do I (should I) coat the rubber washer that forms the seal under the sink bowl with silicon first, or will the rubber itself form an acceptable seal. How tight does this drain assembly need to be? I do not want to crack the bowl---but---I do want a good seal.

thx for any time and effort in responses.

peace

[spot-the-dalmation]

Hello:

I am installng a new one piece bathroom sink (marble/fakemarble type). I purchased a pop-up drain assembly by plumbcraft to install in the sink. I have a couple questions to be sure I get this right:

The flange came with a rubber washer. Most DIY instructions I have seen says to either use silicon sealant under the flange (for marble type sinks) or a strip of plumbers putty. My question is can I use this washer instead? If so, should I coat it with silicon on both sides or is the rubber enough? If not----why? It seems the rubber would create a much better seal. But---that is why I am asking---I have no idea.

On the underside of the sink, do I (should I) coat the rubber washer that forms the seal under the sink bowl with silicon first, or will the rubber itself form an acceptable seal. How tight does this drain assembly need to be? I do not want to crack the bowl---but---I do want a good seal.

thx for any time and effort in responses.

peace

[Speedy Jim]

If the popup came with a seal for the drain flange, I would use it. It won't hurt to apply a thin smear of clear silicone caulk to it (belt and suspenders).

The Mack washer underneath should get caulk liberally applied. Apply it to the threads as well because water will travel right down the threads if you don't.

Just a bit more than hand tight will do it. The faux marble may not actually break but hairline cracks are a problem.

Jim

[MAG]

I'll agree with Jim here. Actually, if one were to do a google search on this topic, one would find Jim helped me out with essentially the same problem backin November or so.

I found that the washer/putty technique didn't give a good seal (Moen drain on a Home Depot - vintage faux marble sink). Dumping the putty and using silicone sealant did the trick, creating a good seal without excessive pressure on the sink drain area. Note that you should give the silicone a full day to cure, maybe two, before testing it.

For me, it worked like a charm.

Marc

[spot-the-dalmation]

Hey, Guys:

Thx for your help and response.