Connecting up a sink drain?

[pods8]

So I picked up a sink drain for the local supply place and it didn't have any directions and I'm pondering the best route to install it. The actual housing and such look similar to the ones on the image below (except the one I have is for a 1-7/8" cutout and it has a strainer rather than plain stopper). So there is a upper flange, a gasket, and a nut to tighten things down. If the gasket goes inside the sink below the flange it'll seal things off but keeps teh drain elevated about 1/8"-1/4" and things won't drain properly.

On a normal sink the gasket goes below but in this case due to some flat spaces on two sides of the lower threading (likely for a wrench) there is a leakage pathway.

Only thing I can think of right now is a bit of silicon under the upper flange and mount that right against the sink for initial leak deterrent and the caulk in the threads and under the nut to seal things off below. Its not ideal and it wouldn't really ever be serviceable without likely destroying the fitting (not that I should really need to) but I don't readily see a better option of hand.

From there I have 90deg adapter that goes to male garden hose threads so I'll likely get a female garden hose to 1/2" hose barb adapter to connect to the old drain assuming its long enough.

 

[Mark W. Ingalls]

Use plumbers putty. Do not use anything permanent.

 

[pods8]

Use plumbers putty. Do not use anything permanent.

I have some on hand I could give that a try. The flat part is about 1" wide and at the deepest part leaves a ~1/8" gap (from memory) you think the putty will seal it up (or are you banking the putty will mainly seal the sink portion thus negating the thread area for the most part)?

 

[Mark W. Ingalls]

If there is that big a gap, then you have the wrong drain assembly.

This is why I hate to do plumbing: dozens of nearly identical parts.

 

[pods8]

If there is that big a gap, then you have the wrong drain assembly.

This is why I hate to do plumbing: dozens of nearly identical parts.

The gap is between the nut and the threaded assemble where it has a flat area, so its between its own pieces. 1/8" would be on the high side. Anyways I went ahead and put it together with a bead of putty at the base of the flange top where it meets the threads. Stuck that through the sink, put on the gasket, and then but another bead around the base of the gasket for the nut to tighten into and tightened it all down. I capped off the drain and poured in a quart of water, after 10-15min there haven't been any drips forming so its likely a success. I'll leave the water in overnight but considering the low likelihood of leaving a full sink stoppered up in the camper I doubt I have anything to worry about. The next test will be how it holds over time as the camper bounces around. Should do well since its flexible and its not like it'll be hard to fix with some more putty if it decides to start dripping down the road (as long as it has a solid run between). Good suggestion.

 

[Curmudgeon]

There should be four pieces:
1) Metal strainer basket
2) Thick rubber gasket
3) Paper gasket (matches rubber gasket)
4) Large nut

The only thing that goes in from the top is the strainer basket. The only thing you should use to seal it to the sink is plumbers putty, between the flange and the sink. Once you have installed the basket from the top, the rubber gasket goes on from below. The paper gasket goes between the rubber gasket and the nut.

JP

 

[pods8]

There should be four pieces:
1) Metal strainer basket
2) Thick rubber gasket
3) Paper gasket (matches rubber gasket)
4) Large nut

The only thing that goes in from the top is the strainer basket. The only thing you should use to seal it to the sink is plumbers putty, between the flange and the sink. Once you have installed the basket from the top, the rubber gasket goes on from below. The paper gasket goes between the rubber gasket and the nut.

JP

I putted below also due to the flats spots on the threads (I assume for a wrench I guess) which aren't normally on sink components that I am familiar with. It left a definite possible leak path. Silly design if you ask me (made in China, go figure) but the putty did the trick.

 

[masterplumber]

Curmudgeon is correct in the assembly order. For the most part the threads on a sink drain never seal so it doesn't matter if there's a gap. The tail piece that connects to the bottom end normally has a flanged plastic or flat cut rubber washer in it to make that seal. The strainer you show in the picture is a tub drain piece which is a whole different animal than a sink strainer - it has tapered threads so that it seals from the top & bottom on the tub. That's because if you have a tub with a trip lever type stopper there is water in that part of the drain when the tub is full. Like Mark said - dozens of nearly identical parts - it's the nearly part that gets you in trouble.
Doug