Ideas from Ed: Drain pain (Vol. 8, issue 10)

edwardpetrus
4 days ago
3 min read

I don’t like surprises -- especially plumbing surprises. I returned home from an evening meeting to find a note from my wife: “Please check under the kitchen sink. I got something from there and it was wet.” Ugh! It didn’t take much detective work. As soon as I opened the cabinet door and crawled under with a flashlight, this is what greeted me:

As ugly as that looks, it wasn’t really an issue for the main flow of water. What was so badly rusted was a “shell” that holds the main drain body against the underside of the sink. The normal flow of water was going down into the pipe system as it should, but apparently (and for some time!) water was leaking around the main unit and getting into that shell. From the topside, the sink looked to be completely normal:

Luckily it was early enough that my local big-box store was still open. I could get there and back, and watch “American Ninja Warrior” finals on our kitchen TV while doing the repairs. (Normally, I suggest NEVER beginning any plumbing at night or when stores are closed. This was not a life-or-death situation as a burst supply line might be, since we could just avoid using that sink for a day if any problems were encountered.)

Most repair work, and this was no different, begins by disassembling the old so that replacement parts can be installed. The plastic pipes were easily unscrewed. As much as I hate the look of plastic drain pipes, they do seal and hold up to decay very well.

Getting the retaining nut to thread off was another story. Despite spraying it with penetrating oil, I could not get that nut to turn, mostly because there is no easy way to hold the main unit in place while turning the nut. The whole thing spun. Perhaps using an adjustable wrench on the thin nut and a pipe wrench on the threads below would have worked, but that meant contorting my body into an uncomfortable twist in the sink cabinet. I reached for my trusty oscillating multi-tool. I’ve said this before, that it’s one of those “must haves” for every handyman. With a metal cutting blade in place, the tool worked like a powered hacksaw and easily cut through the nut:

Once the nut was removed, the shell fell right off, and the main unit was extracted through the sink body from above.

I wasn’t sure when I purchased the new one if I needed the “standard” version or the “deep bowl” version, so I bought both. After disassembling the old, I saw right away that it matched up with the deep version, so I’ll need to make a “return” trip to the store with the other one. In this picture of the new one, you can clearly see the main unit and the shell, and how the shell would press against the underside of the sink to hold things in place:

As per the directions, I rolled a “worm” of plumber’s putty and made a ring in the sink opening against which the unit rests. (As always, I show you what I use/used without any endorsement of particular brands or companies.)

When everything is in place and the shell tightened against the sink underside, the excess putty squeezes out and is simply wiped away with a finger.

Here’s how the new unit looked from the underside before re-connecting the drain pipes. Note that the plumbers putty was on the topside, and on the underside there is a rubber gasket as well as a paper gasket. The paper gasket helps while tightening the nut so that the rubber gasket is squeezed and not rotated:

From there, it was a matter of putting the drain pipes together and testing for flow and leaks. Thankfully, there were no issues, and I even got to see the finale of Ninja Warrior!

I hope all your projects go well. Thanks for reading, and happy restoring!

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