The 90 connecting the down pipe from my kitchen sink was rusted out below the cement... I busted it all up and was able to cut out enough of rusted pipe to get to some nice solid pipe - despite it being underground for the past 60 years.

Prior to this issue... and by the previous owner, ABS had been attached to the original cast just above an old clean out on the vertical down pipe with an MJ. (Like a Fernco, but with a full metal sleve)

I removed the cleanout and the rusted / corroded 90 and some of the horizontal pipe heading for the main line and put in new ABS pipe, 90.

I used a MJ to connect the ABS to the Cast... thought I was home free, but it leaks on the cast side.

The OD of the ABS (2 3/8) is slightly larger than the cast pipe (2. 1/4) is slightly smaller than the ABS... and is a bit rough and uneven despite efforts to clean it up a bit before putting the MJ on.

Is there something I can do to ensure a 100% seal on the cast side? I've thought of putting a couple of O-rings under the MG... or good old silicone... but thought I should seek some advice first... experimenting takes time and my family is getting grouchy without a working kitchen sink.

Thanks in advance.

Hi Leftanote!

Using an abrasive tool such as a wire brush, or a steel file, or even a grinder with a metal grinding wheel all work great to clean the pipe up properly. Heck, I've even used a large wood chisel and a hammer to clean some older cast iron pipes (worked great, too). Here, you may need to make the hole larger/deeper and as much as that stinks sometimes that is what it takes for best result!

Also note that they make a secial MJ transition clamp to transition between ABS and SERVICE WEIGHT (SV) cast iron pipe so purchasing that from a local plumbing supply house will increase your chances that much more.

Steer clear of silicone!

Good luck!

Mark

Thanks Mark... I'll try to clean up the pipe a bit more - pretty difficult to access the underside with anything more than an abrasive stip...

Is the MJ SV any different than the one you purchase at Home Depot or Lowe's? (better hours than the plumbing shops :-))

Also, would it help if the OD of the cast pipe was increased with thin rubber sleeve - like a section of an inner tube from bike? Or is that just asking for problems?

Thanks

You may or may not be able to purchase the appropriate MJ clamp (called a shielded clamp in my area) from home depot/lowes, but you can definitely get the right clamp at the local plumbing supply store (ABS x SV cast iron). Here, the clamp will be built in a manner that acts, "like a section of an inner tube from bike"... ;) This is why I called it a TRANSITION clamp... accommodates the size differences!

Back at you!

PS: There is service weight cast iron (SV) and there is extra heavy cast iron pipe/fittings (XH... larger/thicker in size)... sounds like you have standard size... just so you know the distinction!

Ok... thanks for the education on cast... this house was built a few years before I was born... so always good to know the right terminology when going into a plumbing shop!

I'll save my time tonight and not be disappointed at Home Depot... and head to the plumbing supply store in the morning!

Thanks again.

Thanks for your advice Mark - plumbing shop had a good selection of products designed for the job... superiour to HD or Lowe's! These ones actually had a couple of O ring type bumps on the inside as well... when the SS bands are tightened... there is zero chance of a leak!

Thank you for posting back on your experience!

Mark