The man that fixed the ceiling over our tub cleaned his tools, pan, buckets in the little tiny bathroom sink. Now the drain is clogged and the area below is too small for my husband to get into. Because it was left empty so long the stuff in the sink has really hardened.

My question is - Is there some type of something that I can put in it that

  1. won't cause more damage
  2. won't cause an explosion
  3. won't kill the man who lives in the basement.
  • try this ... pour water into the drain and let it sit, then use a wet vac to suck it out
    – jsotola
    Aug 18, 2019 at 16:59
  • I like @jsotola's idea. Using hot water might help speed things along.
    – spuck
    Aug 19, 2019 at 17:31

3 Answers 3


To follow up Willk's post, you could also try brick acid (hydrochloric acid). The acid will dissolve the calcium sulphate†, and that might break up the glue enough to flush it down.

Do not mix lye and brick acid

They will combine violently, and potentially cause a lot of damage.

If you want to try one and then the other, make sure to wash the first away with copious quantities of water before trying the second. (A sequence may be quite effective though. The lye destroys the glue, and the acid destroys the gypsum).

† I'm British. I spell sulphate with ph.


There's a good chance the clog is in the trap right under the sink. Someone should try to remove it and clean it out. If it's not the trap, get a cheap drain snake and run it down the drain with the trap off. I'm not sure any of the drain cleaners would work on spackle. Good luck.


You could try lye (sodium hydroxide).

Lye is drain cleaner. Spackle is gypsum (calcium sulfate) and glue. Lye will definitely dissolve glue and that might break up the gympsum enough to flush it down. I was not sure about calcium sulfate - it is pretty unreactive. I am still not sure but I found a patent for clearing gypsum deposits off mining equipment using sodium hydroxide where they said the gypsum turned to paste that could be carried off by water.


I would give the lye a try.

If no good, flush the lye out before you monkey with the plumbing and then try taking the uBend off and see if that is where the clog is. You can throw the old one out and get another one. If your husband does not fit under there maybe you do. If neither of you fit, hire a plumber.

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