2

I need to remove the existing PVC to cast iron adapter in the main waste outlet of my basement. Another PVC fitting will be added in place.

This is a 4" cast iron with a rubber ring that seals between the PCV and the iron.

Here's what I've done:

  • PVC pipe will rotate freely in the rubber.

  • PVC pipe will deflect left/right up/down a few degrees without much force.

  • Added some soap as lubrication. This made the above 2 things a bit easier.

  • Pulling outwards: it won't move at all, even while pulling and rotating/wiggling at once.

I had imagined that this was a straight pipe passing through a rubber "donut" but after what I've tried so far, I'm not sure. It feels like something solid is preventing it from pulling out.

I could cut the PVC apart as I don't need to reuse it. But I don't want to damage anything inadvertently (especially the cast iron) and would rather do it right if that is possible.

Thanks for any advice!

enter image description here

Improve this question
5
  • Is that a cap on the cast iron fitting? Can it be rotated? Can you pry the rubber seal out? – JACK Jan 11 '20 at 17:46
  • @JACK I will take another look but it appeared to be all one piece – StayOnTarget Jan 11 '20 at 17:49
  • 2
    The large plastic adapter could be broken up with a hammer and a chisel. Cast iron pipe like what you have here is nearly indestructible, so unless you start wailing on it with a sledgehammer, there should be no problem damaging it. – jwh20 Jan 11 '20 at 22:14
  • pull on the rubber part, as it stretches it gets thinner and will let go. – Jasen Jan 12 '20 at 9:29
  • @Jasen thanks - I thought the same but although I could stretch it a lot nothing I could do would produce any total net movement of the rubber part. – StayOnTarget Jan 12 '20 at 10:40
2

If it's all one piece I'm inclined to believe you have a donut and coupling similar to the ones below installed in you cast iron pipe.

enter image description here

enter image description here

I have only used these one time, but I had to hammer the piece of PVC into to rubber donut because it fit so tight. Some PVC fittings have a lip at the tip, like the one below, that would make it harder to remove once it was installed. I think you're going to have to work it out, pulling and twisting, using a lot of elbow grease.

Improve this answer
0

It ended up that I decided to cut the fitting apart. Nothing I tried could budge it outwards at all, though as noted it would wiggle around in other directions; so this started to convince me there was a "connection" inside more than just friction.

(I tried pulling, rotating, using a 4" lever, vice grips, etc.)

I cut the PCV with a demo saw in 2 places and then broke it out with a screwdriver & pliers. It did indeed have a lip which extended in beyond the rubber gasket. This photo shows a similar type of lip:

enter image description here

I didn't get a pic of the actual fitting because I didn't want to take out my camera in such unclean conditions at that point.

In conclusion I am not sure what the "right" way to remove this would have been (without cutting it). Maybe there is no way because the rubber's friction to the metal far exceeded anything I could use to pull on the rubber. Probably a plumber would know the right technique! But, because DIY.

Edit: In hindsight I realized I never tried heating up the PVC. I bet that would have done it. An electric heat gun can get PVC to become "floppy" and I'd done this in other circumstances.

Improve this answer

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.