Joning CI to ABS...drip...drip...drip:)

I bought a ferco fitting to join these two but the cast iron has been underground for 80yrs and is a bit bumpy on the outside I tried to fit them together but the CI end keeps dripping water out.

I've tried to smooth the surface with a wire brush with little success,anybody got any ideas? Is there some kind of a leak proof sealant I should use on the outside of the CI?

Thanks all

Have you considered replacing the cast iron with PVC?

The CI has about a 15" run into a CI hub(elbow fitting). I've no idea how to get the CI out of the hub, would welcome suggestions!

Unless the surface of the cast iron is super bumpy or flawed in some other way, I don't think you should be having a lot of trouble. My best guess is that you are either not using the proper sized coupling or you are not tightening the clamp to the appropriate torque. Have you tried tightening the gear clamp with a ratchet? You can definitely get more torque using a ratchet than with a nut driver.

If it's old cast iron, I use a mission coupling made for copper to cast iron.

The older sizing is 4-1/8", which is too small for most couplings.

If the CI has been underground like you said and is bumpy, you can lightly chip away at the bumps and that will make a smooth surface to join to.

grease it up with pipe dope

When this happens to me I usually get out
my trusty can of PRO DOPE......its grey and very stickey
they have something similar to this at Lowes ..its very
cheap.....


Usually if you liberally smear the pipe dope on the cast
with your hand all around the fitting,
and then put a liberal amount inside the fitting it will
seal the gaps in the pipe very well......

when you tighten it back down some will squeeeze out
and it should put an end to the drip

Thanks for the ideas guys, I realy appreciate it. Would I find a mission coupling in Home Desperate? or is it more a speciality shop item?

A Mission coupling is also known as a no-hub coupling, and you should have no trouble finding one.
As for rough CI, you can use a variety of things to help seal it from pipe dope, to plumber's putty, to caulk, to plastic roofing cement, etc.
Mike

Thanks for that. The coupling i used was neoprene with a metal band on each end. This joint will be under concrete,should I be using a fully banded coupling or am I using the right one once I put some pipe dope on?

You need a banded on above ground, the unbanded one under, so you have the right one. Make sure to backfill carefully to keep the ends aligned. Pipe dope sounds like the longest lasting. A piece of rough sandpaper might smooth things out a little, too.

Taking the cast out of the hub is tedious, but if you have full access not too bad (I'm not a pro, the last one of only two, I did took maybe 1/2-hour on a 4" hub). Find a drill bit the thickness of just under the width of the lead in the joint. Make swiss cheese of it all around the pipe. Work it back and forth a bit to loosen the pipe, then dig it out. You should be able to get all of the pipe, lead and oakum (oiled hemp) out. Finding the proper sized Fernco dognut to insert may be the harder task, but sometimes you are lucky and find the right one. They come in numerous sizes since cast is only sort of standard (the lead filling the gap isn't super critical, so the size of the hub isn't - as long as the pipe fits in and there's enough room to put in the oakum and pour lead in, they didn't care that much). Basically, then, the connection would be to insert the dognut, then push the new pvc into the hole. If you get the right exterior diameter for the CI, it makes a great seal. If it is too tight, you may never get it in, if it is too loose, it leaks, so specifying the proper size is important. I'm not sure, but I think I remember seeing them in 1/16" steps in the catalog, and you may only have one or two choices stocked locally.

coupling under concrete

cruiser said:

Thanks for that. The coupling i used was neoprene with a metal band on each end. This joint will be under concrete,should I be using a fully banded coupling or am I using the right one once I put some pipe dope on?

Click to expand...

a fully banded coupling is probably best,
it has more firmness to it

although I usually just use the fernco type because they
are more forgiveing when working with them

whichever you use , maybe you ought to throw
some concrete into the hole so it never moves and
makes everything more pernament

Terry said:

If it's old cast iron, I use a mission coupling made for copper to cast iron.

The older sizing is 4-1/8", which is too small for most couplings.

Click to expand...

Ive read this comment multiple times on this site and you are correct! Replaced my stack and it was 4 1/8"! I picked up the copper to cast as the suggested band was too big. When I asked the inspectors, local plumbers, and supply store the all said 4" cast is the same size...its not!

I've seen old cast be 4-1/8" and I just worked on some newer cast from the 60's that was 4-3/8"
Plastic is a little larger. More like 4-1/2".
It never hurts to have three types of couplings on a job and then return the two that you don't use.
The very old cast is often smaller at 4-1/8".