Remodeling a structure built in 1960.

The drain (waste pipe) for the bathroom sink has a 1 3/8ths (1.375) inch OD and is made of brass or copper. Currently this pipe is flush with the drywall and I need to adapt it to fit a vanity/sink when I pick one out. I have been to both of the local big box stores asking for suggestions on how to adapt this to modern sink waste drain pipes with no luck. From my discussion with them, 1.25 is normal for bathroom vanities...so this is what I am trying to adapt it to.

Closest suggestion I got was someone saying to use a 1.25 to 1.25 inch rubber union...but measuring the uncompressed union showed it had an ID over 1.5 inches. A softer rubber (thinner?) one that actually measured 1.25 ID might work (if I can stretch it over the 1.375 inch pipe and put a clamp on it), but I have been unable to find such a critter. I figured I could roll it onto itself on a metal 1.25 inch pipe, slide that into the 1.375 and unroll it over the union between the two pipes and put two clamps on it.

Any input would be appreciated.

Thanks,
Sean

That would be 1 1/4" copper tubing. They do make a trap adapter for that size, but it is usually a special order since it was a size that was seldom used.

Well...stopped by two of the local plumbing supply places, and still no go, though one did recognize it as the 1.25 inch tubing you mentioned. One did steer me toward the rubber boot idea I had earlier without any prodding from me.

I have also tried googling the terms you used (1.25 inch copper tubing trap adapter), and have not had any luck locating it online.

Sean



Edited 3 times.

Are you able solder? If yes, solder on an 1¼" male adapter and use a rubber sip joint washer. How was the original trap arm attached?

exactly.. one 1 1/4 copper x male DWV adapter. a 1 1/4 slip nut and cone shaped washer will fit it.
in the old days we used a 1 1/2 x 1 1/4 copper elbow with a short piece of 1 1/4 copper tubing sticking out of the wall. then sand paper the chrome off the trap arm and stick it into the 1 1/4 tubing and solder it. trim it with a deep chrome flange and done..
remember, mass doesn't allow slip fittings on the outlet side of the trap so we had to be clever about it.

"Are you able solder? If yes, solder on an 1¼" male adapter and use a rubber sip joint washer. How was the original trap arm attached?"

It's been probably 20 years since I have sweated pipes. I am capable of doing it again. My guess is that what I am looking at is the female 1.25 tube (so the ID is 1.25 inch).

So I ordered a piece that is male 1.25 and threads on the other side. Not sure if this is what you are speaking of or not. Figured when it came in I could take it to the local box store and see if I can adapt that to the standard 1.25 inch waste for the sink.

What is a rubber sip joint washer? I take it you are talking about the normal compression joint (or whatever they are called), but instead of using the Teflon washer, to use a rubber one? Not sure what the adapter is in what you said. If I put a piece of 1.25 inch male tube in and solder it, won't a normal compression fitting fit this? What is the adapter?

I don't know how the old sink was connected...I paid a couple guys to tear out the old and rough in the new...but that is a nightmare for a different thread...

Sean



Edited 1 times.

Sean, if you have an 1¼" copper pipe stub, I thought that it might be easier to obtain an 1¼" pressure male thread adapter, than to get an 1¼" brass trap adapter. The trap adapter would use the tapered nylon washer, where the male adapter doesn't have the matching bevel machined into it, so a rubber slip joint washer would seal to the adapter.

Nibco makes 1-1/4 AND 1-1/2 Adapters


DWV Trap Adapter C x SJ - Wrot, 901-7

Drainage Waste and Vent trap adapter Copper x Slip Joint, Wrought Copper, 901-7, 1-1/4

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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638