Bathroom sink drain soldered - is this a good plan?

Users who are viewing this thread

Chris Branson

New Member
Reaction score
Winnipeg, Manitoba, Canada
Hi Everyone,

I'd like a sanity check on my plan for what I think I need to do from what I've read in other posts on the forum.

There are 2 places on this sink that have a "nuisance" leak that I'm sure are ready to go catastrophic at any minute, so I'd like to replace the sink and all of the plumbing back to the trap arm (or at least that's what I think that is). The plan is to remodel this bathroom after the other bathroom in the house, so I'd like something to get through maybe the next year. I've never tried to sweat copper and would prefer to not cut open the back of the cabinet and wall and I think that the copper (does that look like 1 1/4" copper?) close to the wall is in good shape.

The first leak is obviously around the sink drain, so it's time for a new sink, I'm sure.

That hose clamp is pinching tight the nut that seems to have cracked all on its own. Because the pipe is flared, I've no idea how to get a new nut around the flare to replace it without removing the drain pipe, but it appears to be soldered everywhere. I looks like I nee dto cut the pipe which would, of course remove the flared end.

I'm thinking of getting a large tube cutter and cutting that drain pipe just behind the 90 degree curve and using a Fernco style coupler to attach all new ABS drain plumbing and sink.

I'm assuming all this white buildup is some sort of corrosion - can I get rid of that somehow? I assumed that I should at least where the coupler would go?

Does this seem like a good plan? Am I missing anything?

Thanks everyone!

20220414_204615022_iOS (2) (960x1280).jpg
20220414_204510048_iOS (2) (960x1280).jpg

20220414_204453304_iOS (960x1280).jpg


Well-Known Member
Reaction score
1. 1-1/4 copper is 1.3875 OD. Get a digital caliper to make measuring easy.

2. For a bathroom sink I would use the shielded coupler to connect to a "spigot" trap adapter. Spigot means the od is the same size as a schedule 40 pipe would be. The trap adapter can be ABS. Then use polypropylene slip-joint trap to connect to the new basket. Chrome-plated brass is interchangeable once you get into the slip joint area. I would not glue the anything before the shielded coupling. Fernco and Mission are brands. Fernco-type may be interpreted as non-shielded, because that is what they made originally. But now Fernco branded shielded couplings are readily available. has sizes, and even cross-references the Mission numbers.

3. You can use a 1-1/4 inch trap adapter, but it may be easier to find a 1-1/2 spigot trap adapter, and use a reducing washer to connect to the 1-1/4 trap. A Fernco 3001-1125 or P3001-1125 or Mission CK-1125 could connect from 1-1/4 copper pipe to the 1-1/2 spigot trap adapter if I did that right.

4. I would avoid a vessel sink, but others might find them charming. The overflow of a regular sink not only serves as an overflow, but also provides a vent to make the sink drain better.

5. Technically, the trap arm is the whole path from the output of the U of the trap to the vent in the wall.
Last edited:

John Gayewski

In the Trades
Reaction score
Cut the copper pipe just after the 45. Leave enough to sweat a new brass trap adapter onto the copper pipe and 45. Then use a new tubular trap and sink drain.
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks