Here are the pics.

The plug that came out:

Another shot of the plug:

Sort of sideways shot of plug - the coppery part goes up into the hole in the trap pipe:

Trap hole where plug came out of:

Another shot of the hole in the trap where the plug was:

The S-trap under the sink:

These are the puzzling (to me) parts:
- The plug has been fine in its hole for the past 5 years that we've lived here.

- My husband just gave it one turn and it came out. (We're thinking now that maybe it was holding on by a little bit and broke off??)

- There are no threads on the hole in the J-pipe. It's as if the plug was designed to just stick in there.

If there's a term for this sort of plug that I can use to Google more info, that would be a great help also.

Thanks!
Lee

For the curious about the outcome: DH managed to get off the existing J-pipe and replace it with a brand shiny new one. :-)

It was a struggle (I think 30 minutes of tugging and knocking and trying to make sure he didn't damage the other pipes). No plug on the new one, but no leaks, yay!

Looks like an old (and illegal) s-trap.

Consider replacement.

First off, that is not a J-bend. A J-bend is a straight length of pipe with a 90deg bend on the end. The pipe is question here has a 180deg bend and it is properly called a "Return Bend".

When that return bend was initially made they began by making a straight return bend without a cleanout hole. They then drilled a hole at the cleanout location slightly smaller than the desired finished opening and the tubular brass of the bend was then swaged out to form the finished shape and size at the cleanout location. A short piece of threaded brass tubing was then inserted into the opening and soldered in place and finally they screwed the cleanout cap on the end of the threaded brass tubing.

In this case over time the threaded brass tubing corroded and fused into the cleanout cap so that when the cleanout cap was turned instead of the cap unscrewing the solder joint broke and the treaded tube came out of the return bend. If you examine the section of brass tubing extending out of the cap in the last photo you can see where it was originally soldered into the tubing. That problem is quite common when working with old tubular brass fittings and generally Plumbers do not even attempt to remove the plug, but rather they take the entire return bend off to open the line for cleanout.

It was mentioned that this is an "S" trap, which is illegal, but that is not correct.

It is true that S-traps are now prohibited by code and may no longer be used for Plumbing, but here we run into an issue of semantics.

"Plumbing is defined as the act of initially installing a piping system whereas the act of repairing an existing system is defined as "Maintenance".

When performing Maintenance we are required to maintain exactly the original configuration, therefore given that an S-trap was code approved when that line was first installed you are required to replace it with an S-Trap.

If you were to move that sink or do a rehab on the bathroom that involved changing the location of any fixtures or the physical configuration of any of the piping you would then be performing an act of plumbing and as such, all plumbing within that room would have to be brought up to the code that is in effect at the time the rehab is performed.

"therefore given that an S-trap was code approved when that line was first installed you are required to replace it with an S-Trap. "

While you may be able to continue to use an S-trap under the grandfather rules, you are NOT required to continue to use an s-trap.

Grandfathering is a permission, not a requirement.

Any number of jurisdictions have required that older installations NOT allow grandfathering of some methods.
Ask you local AHJ.

The national codes are model codes.

Jurisdictions are free to alter them as they wish when adopting them.

When performing an act of maintenance you are required to maintain the exact same configuration as the original layout. Any alteration of the original design is an act of plumbing and the local AHJ would be well within their authority to demand a permit and require the entire room to be brought up to current code.

But then if you were a real plumber you would have learned that in the apprenticeship classes.

And what constitutes maintenance is subject to the enacting statutes that the local AHJ obeys.

It is very far from uniform.

If you actually read the local enacting statutes you would realize the model codes are rarely adopted in their entirety without modification.

The extent of changes required when a portion of the system is altered is often in the enacting statutes.

In this instance the correct course of action was to repair the S-Trap but since you seem to be so insistant upon changing that drain to a P-trap perhaps you would care to explain how the pipe would have to be reconfigured to fit in a P-trap and meet code compliance.

Hi, the OP here. Wow, I didn't expect to get any responses after I posted that my spouse had replaced the pipe with that darn hole in it. :-)

brickeyee, thanks for posting. Your comment that it's an old S-trap is spot on. It looks exactly like a drawing of one that's in my "How Your House Works" book.

Why the S-trap is no longer code? I mean, the limited amount I know is that a trap is supposed to have the water in the pipe to prevent sewer gases from coming up and killing us. I presume in the past the Powers That Be thought the S-trap was good enough for the past. What's changed that makes it not good enough in today's world?

lazypup, thank you so much for responding with the description of the "swaged" piece and soldered joint! That totally makes sense with what I was seeing! I can't tell you how nice it is to have an answer to that part of the puzzle. (It would have sat in the back of my mind and bugged me.)

And I have to admit--though you both have more knowledge and experience than I do--it does make me feel better to hear there's a difference between "plumbing" and "maintenance" (or at least, that in some places, the AHJ would recognize a difference). This is an old house, and even though in an ideal world, it would be better to upgrade the S-trap to a to-code trap, I find I have to pick my battles with what to upgrade and when. I do find it heartening to hear that I don't have to dread calling a plumber if and when this sink has a problem, for fear that he's going to be required to tell me that to fix the S-trap from leaking would mean re-venting that sink by breaking into the wall behind it (which is what I think it would take to put a P-trap there).

So, my appreciation to both of you, for taking the time to provide the knowledge that you did here. I thank you, and I'm sure that someone someday running across this thread via a Google or GW search will also thank you! :-)