Just purchased a new house has double sinks in the bathroom - when you use 1, after about 30 seconds of water running, it starts filling up, after about 1 min of water running, the other sink starts filling - I did a draino treatment the other day, seems to be draining a bit quicker (still takes like 20 minutes for a complete drain), but still am having problems with the other sink filling, and have realized it is leaking underneath (the spot where the metal pipe meets the pvc pipe is where water is collecting and spilling over) I will purchase more draino and do another treatment of that - any thoughts on if this is more than just a clog? (just fyi - yes, I'm standing on the toilet to get the picture of both sinks, and yes, I know that the coral countertop and floral wallpaper can no longer live together, only one will survive - haven't decided which one yet ;) ) The second picture is under the sink on the left, the third picture is under the sink on the right.
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Cute socks too!! And a cast iron sink! I would guess hair clogs, common on bath sinks. Although I don't recommend liquid cleaners because of their corrosive nature, you may want to try again. I would also go to HD or Lowe's and get a ZIP-IT. You can slide it around the pop up, down the drain and be amazed of what it will pull out. Tighten the plastic and metal nuts under the sinks. If necessary, you can take out the traps and clean them manually. You may also have to use a small auger to clean out the piping in the wall. All of the suggestions are easy DIY projects.

Okay! I find myself realizing what the true cost of home ownership is - there is no 'calling the landlord' any longer. Thank goodness I work for an electrical contracting company, have already had a breaker replaced, and some outlets installed free of charge. Plumbing, however, is a whole other thing. I have a friend who has offered the use of a 'snake' thing - I'll take him up on it and we'll see what is dredged out of pipes... the sinks are cast iron? Guess I didn't notice - that's a good thing? So I'm guessing the exposed sink is ceramic and the 'casing' of it is cast iron?

In addition to the above response...

I see you have cast iron drain fittings. Also both sinks combine in Double "Y" fitting inside the wall, meaning, they share common drain. Since your sinks back up so quickly, the blockage will be right inside the wall and in the common pipe. Take 1/4" snake, remove the white tubular drain under sink and snake it from one side.

Moreover, looking at your photos, it seems to me you have black 1 1/2" nipples ( one under each sink ) between the fitting and PVC pipe. If that's so, and while you're there, replace. Otherwise, it will eventually become another problem.

Hope that helps. Back to you. Milo

Since one sink can backfill into the other sink and they do not have a common drain or trap your clog is further down inside the drain line. I would remove the chrome nut ring between the PVC and cast iron pipe and rod directly into the drain line, you might go several feet. You are probably too far downstream for a zipit to help but that is the normal starting point

Remove the traps from both sinks and snake the drain(s) into the wall.

You should not have to snake more than 5-10 feet at a maximum to get to the problem area (where both sink drains join a common drain pipe). Snake the drain in and out 3 or 4 times and then put one trap back and put HOT water into the sink. If water goes down even a little, keep running hot water going down the sink/drain while you snake through the other drain a little bit more....this will really help clear the drain pipe now!

If the snake just shows up at the other sink when you are snaking the drain then you have a CROSS fitting in the wall and you will either need to rent a snake with a DROP HEAD tip, or you may need to get access into the common sink VENT!!

Good luck!

Mark