Sunday, December 12, 2010

Sink Repair

A few months back I did some repair to the 2nd-floor shower. I prefaced it by saying that plumbing repair is something that I approach with some trepidation, because even though it is a straightforward trade, even the smallest jobs seem to become involved projects, and the potential consequences for getting it wrong can be pretty bad.

So when I resolved to delve into why the 2nd-floor sink was draining very slowly, I approached the job with the same reservation I did with the shower. But I am a homeowner, dammit, and I can Do It Myself! This repair, like the last, involved a lot of cursing, particularly at those unknown people responsible for the state of things. Why, for instance, does the sink not have shut-off valves for the hot and cold supplies? Why would you slather five coats of paint all over the pipes and fittings, knowing that it would make it impossible to properly service the thing without chipping that paint away? Why bolt a sink to the wall in the first place, leaving the plumbing underneath exposed?

In any event I grit my teeth and dived in. I did not have the presence of mind at the outset to get a picture of the plumbing before I started. At the time, I didn't think that I would end up replacing most of it. I undid the slip joints for the trap, breaking a lot of old and peeling paint, and not a small amount of rust and corroded copper. The drain - from sink to floor had a nice, gooey, disgusting, but mercifully removable 1/4" coating of accumulated slime. This would go a long way to explaining why the drain was slow. The trap - a single cast piece of brass that was certainly decades old - had a removable plug at the bottom to help with cleaning. I pulled a nice motherlode of unidentified gunk from there, too.

Twenty minutes well spent: I started reassembling things. It was here, while tightening the last joint between the trap and the drain pipe sprouting from the floor, that things took a bad turn. My pliers slipped, and I ended up crunching a 1/4"-square window right through the pipe. The pipe, as I noticed when I had everything disassembled, was chrome-plated brass, heavily corroded, with walls not much thicker than aluminum foil. I could chip away at the edge of it with my fingernail. The coats of paint on it were probably structural. My first quick-fix solution was, of course, to wrap it in duct tape. This, however, was not watertight, partly because the crack extended into the joint, but also because it was hard to get a good purchase on the old paint.

The real solution was to lop the pipe off and hope that it was more sound a few inches below. However, this meant that I would need to somehow extend the pipe somewhere else to make up the difference. This spawned trip to the hardware store #1. I purchased a 6" pipe extender and, for good measure, a replacement sink drain assembly. The sink drain assembly is what mates the pipes to the ceramic bowl of the sink. There's a flange - the part you see at the bottom of the sink, which is threaded into the pipe that extends down below. This length of pipe usually also has the built-in plug that you can open or close by pulling the knob between the faucet handles. How it seals to the sink is actually underneath: a big rubber washer gets pressed to the underside of the sink with a wide nut.

The new sink drain assembly went in easily enough. The old one was very reluctant to leave, however: it had basically been frozen immobile by accumulated corrosion and grime. The resulting splatter when I broke it loose was unpleasant to say the least. But I'm a man! A Handyman! A Homeowner! and I laugh in the face of such trails!

Next came the old trap. Before I screwed the plug back into it, I started chipping away at some of the accumulated paint. I did not realize at first, but I was also managing to chip away the dried and cracked gasket that sealed the plug to the trap itself. Casting about for a suitable gasket material from which to cut a replacement, I settled on garden hose: slit it down its length lay it flat, it actually has a decently rubbery inside lining. Close Enough, I declared. And, believe it or not, this worked.

Chopping down the old drain pipe proved difficult. I first tried a pipecutter, but all it did was flex the flimsy thing out of round, which opened up a nice crack along its length. Next I tried a hacksaw. This worked at first but, as the cut progressed, the pipe began to chatter so much that I worried about breaking it more. My final solution: tin snips.

I assembled it all back together, tightened everything down, and turned on the faucet to test. It worked at first, but after a few minutes I started seeing drips welling from, well, every single joint. Cursing, and knowing that I wouldn't really be able to live with a drain that leaked that badly, I started poking around to diagnose. My conclusion: none of the joints were lined up properly; they were all slightly askew, which made it difficult to get a good seal. The root of this problem stemmed from the fact that the location of drain pipe in the floor and the sink above, and the fact that the trap that joins them is a single rigid piece, leaves little room for misalignment.

So came trip to the hardware store #2: I purchased a new trap assembly. This one, however, broke the S-bend into two parts, which can take up a lot of misalignment between the pipes above and below. For good measure, I disassembled the new sink drain assembly and, while reassembling it, applied liberal amounts of caulking. The joint where the trap meets the drain pipe in the floor received similar treatment. Then I left it to cure overnight:

So $40 in materials, two trips to the hardware store, and about five hours later, the slow drain has been fixed. A Pyrrhic victory?

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