Bathroom sink gets repeatedly clogged. What to do?

[Khadaji]

I have used the foamy draino. I pour one chemical down (I put a piece of tape over the other side.)

Then I pour the other chemical down.

I run hot water and use a plunger.

This seems to work for a few months.

[ralph124c]

Sounds like my bathroom. A few years back, I had to replace the drain pipe and trap assembly (a hole was in the brass drain pipe). THe pipe had so much crud built up that the effective inside diameter was about that of a pencil. I scraped it all out with a paint stirrer, put it back together, and all is well. I reckon that the pipe had been there since about 1960, so not too bad.

[Spiderman]

@BobLibDem

Put a bucket under the trap, remove the trap. Remove the pop-up stopper if you have one (the sink, not your browser). Wad up a piece of toilet paper and get it wet. It should be big enough that you have to force it down the hole. Force toilet paper wad down the hole and out where the trap used to be and into the bucket. You might get a nice cylinder of black slime. Wad up a small bit of paper towel and wet it down. Then shove it into a vent and force it all the way through with your snake until it reaches the drain tube and out in the bucket. Then reassemble and dump the slime and water in the toilet.

This. Well a variant. I pull the j-trap & use an old toothbrush to scrub the gunk off the inside of the drain pipe, around the stopper & out of the j-trap. If you have a snake, insert in from the opening, which will give it another foot of reach.

[Mk_VII]

Have you tried caustic soda [sodium hydroxide]? The crystals need to be carefully mixed with cold water first (always add the crystals to the water, never the other way round).

[Magiver]

@J-P_L

Is your sink the type that has the pop-up stopper with the push-pull lever sitting somewhere atop the faucet.

If yes, these can generally be taken apart from below the sink, if you do, you may find clumps of hair and gunk trapped by the linkage, rinse it out and re-instal and you should be good to go.

or remove it and leave it out. Some sink drains are smaller than others and no matter what you do the pop-up stopper will clog. I found this out after replacing all the drain pipe with long radius PVC connections. The sink still stopped up. Took out the stopper and it never clogged again.

[Magiver]

Oh, and don’t use drain cleaner if you have iron pipe. It ate a 2" X 8" chunk out of my drain line. It was quite the adventure replacing it all.