P-Trap Replacement Woes (Bathroom Sink)

[`Chelle]

Ohh, I hate my house. Built in the 1950s, then "improved" in the '70s by the previous owner who considered himself a bit of a handyman (he was wrong) to get a better price for this hell hole.

Okay, now that's out of my system, here's the deal: Discovered a leak in the cabinet under the lavatory sink (chrome plumbing, not PVC). The slipnut on the outlet part of the p-trap (AKA j-bend) was seriously corroded -- an entire gap was missing, and removal of it from the waste arm (which it easily slid up) just made it crumble. A trip to the hardware store resulted in a new, apparently matching p-trap with two new slipnuts.

This is where the trouble began.

Problem 1: No threads...anywhere. There's an existing coupling piece on the tailpiece which tapers, so I'm assuming its purpose is to accommodate the width and height of the p-trap. In cleaning the tailpiece in preparation for the new p-trap, this coupling came off. All the gunk inside gives the impression this is meant to be stuck on the tailpiece with plumber's putty or adhesive? The end of the coupling piece is also perfectly smooth. One wonders what the slipnut is supposed to grab.

On the wall side, the mouth of the waste arm is also completely smooth.

Which leads to...

Problem 2: The guys at the hardware store as well as the p-trap package instructions say the slipnut should be able to go up around the pipe of the waste arm, and come back down to rest at the mouth where it connects to the threading of the p-trap. My waste arm has a wide ridge about 1/2 cm above the mouth. The slipnut will not go past it. There is nothing on the waste arm for the slipnut to hold onto. (The old, corroded slipnut seems wider than the new, thus explaining how it could get past this ridge.)

When fitting the new p-trap against the mouth of the waste arm, the little bit of mouth under the ridge seems to go inside the mouth of the p-trap outlet, and that outlet rests snugly against the troublesome ridge, but how to lock the two pipes together?

Problem 3: Even if all the ends locked together nicely, the new p-trap will not fit. It's just a little too curved to align correctly to both existing pipes. Hardware store guy said to loosen something at the wall and pull the waste arm pipe out a bit until it fits, but that doesn't look like it's going to happen, as I believe the darn thing is "leaded into place." Research has shown that it is possible to buy a flexible p-trap that will bend to fit this situation, but can one put PVC to chrome?

This link http://www.a-ball.com/tips/basins.php?shopky= seems to give a hint as to how to approach my problem, but I'd appreciate some more detailed advice before I go chopping off bits of plumbing.

I hope I've explained my problem clearly enough. Any more detail needed, just let me know. And thanks in advance for any and all attention and advice.

[LazyPup]

Examine your new P-Trap kit.
Lavatory drains are 1 1/4 inch drains. Often in new construction the waste arms are 1 1/2inch pipe and they use a combination 1 1/4 or 1 1/2 P-trap. (the kits have two sets of compression sleeves, one for 1 1/4 and one for 1 1/2 x 1 1/4)
Make sure you P-trap is for 1 1/4,,,(not a combintation trap.)

Examine the parts for the P-trap, you should find:

1.one piece of tubing about 8 inches long with a 90 deg bend on one end and narrow flange on the end of the bend.
2. A shorter J-shaped piece of tubing that has a larger diameter on the longer end and threads on both ends.
3. You should have 2 slip nuts and one compression sleeves with the P-trap kit. The compression sleeve will be a narrow ring of semi-clear piece of platic that is bevelled toward one edge and will fit over the tubing.

To assemble the P-trap begin by selecting a slip nut and the long J shaped piece of tubing. Slide a slip nut onto the tubing with the open threaded side of the nut facing the tubing. Slide it the full length of the tubing until it stops at the flange on the end of the 90 deg bend, the threads should now be extening out over the flange and away from the pipe.

Now select the J-sahped piece of tubing. Notice that it has a larger diameter on the high side of the J and has threads on both ends. Fit the low side of the J (small diameter end) to the nut you installed on the long tube and screw the nut onto the threads snug but not tight. (You will need some movement in this joint to adjust everything as you go.)

Now examine the tailpiece coming down from the sink. It should be clean and smooth on the end. (The gunk you found on that is the remnants of soap, toothpaste and such.)

Select another compression nut an slide it up onto the tailpiece with the open thread side down.

Examine the compression sleeve and you will see that it is beveled to one side (wedge shaped)
Slide the compression sleeve onto the tailpiece with the thin side of the bevel down.
Slide the larger diameter end of the J part of the P-trap up on the tailpiece until the tailpiece hits the bottom of the enlarged part of the tube.
Now slide the compression sleeve down to meet the P-trap, then slide the nut down and thread it onto the threads on the end of the P-trap. Make it snug enough to hold in place but do not tighten at this time.
Examine the end of the waste arm where it extends out of the wall. If it is a metal pipe, there should be threads on the end of the pipe. There may be an existing compression nut on the end of the pipe, if so, remove it and use a rag to clean the threads on the pipe as best you can.
Slide a compression nut on the long piece of tubing on the P-trap, the open threaded side of the nut should be facing toward the end of the p-trap tube. Slide it back 2 or 3 inches, then slide another compression sleeve on the tube with the thin side of the bevel toward the end of the pipe.

The end of the P-trap tube should now slide inside the end of the waste arm pipe. (It should slide into the waste arm pipe about 1 1/2 inches, you may need to cut the end of the P-trap tube to fit)

You may also need to rotate the P-trap at its center coupling or on the tailpiece to align it to the waste arm. Once it is aligned and inserted into the waste arm, slide the compression sleeve up to the end of the waste arm, then slide the nut up and thread it onto the end of the waste arm pipe.

You may now tighten all joints. PVC should seal with hand pressure and should not require tools to tighten.

[`Chelle]

Thank you, LazyPup, for the detailed instructions. A return to the hardware store resulted in the purchase of a flexible PVC p-trap. Its combination of metal washer and various-sized plastic compression rings made a pretty good fit on the tailpiece. As for the troublesome ridge on the waste arm, we ended up just sawing the pipe off right above it.
The assembly isn't the sturdiest fit in the world (as there aren't any threads on the existing pipes to grab), but it holds and does not leak. Good enough.

[LazyPup]

Since you do not have any threads on the metal pipe you can use a Rubber "Fernco" coupling to connect the trap tot he waste arm. They are inexpensive, easy to install, and it would make a code approved joint to solve your problem. You can get them at any hardware or builidng supply store.

I prefer not to use the flexible P-traps becasue they tend to clog up more than a regular p-trap, however there are times when you have to do what you have to do.

[kactuskid]

I agree, You should use a Fernco rubber boot. This is a rubber coupling. Here's a link that shows one:

http://www.brandnametools.biz/plumbing/p/Pipe_Couplings/

One end slips over the drain piping stubbed out of your wall. In the other end you'll have to install a threaded male pipe nipple They're also called a street fitting but the picture on this link will give you an idea of what you need. http://plumbing.aubuchonhardware.com...ack-432696.asp

They're only about 2 inches long. Install it about 1 inch into the Fernco boot, tighten down the clamp. Then the threads that stick out from the boot are where you attach your PVC. Apply teflon tape to the threads and use a metal nut around the PVC.

This will give you a much better seal and also be sturdy.