Fernco Multi-tite donut won't seat 100%

Hi folks,

After wrestling for about 4 hours with a cracked length of 4" Cast Iron vertical stack, I finally managed to get it out. Only to encounter another issue...

The fernco multi-tite donut won't seat in the CI hub 100%. It's got 3 ribs around it and then the top flange. I've got 2 of the ribs in all the way but the top rubber flange is flush with the hub only on one side. In other words, the 3rd ribbing of the donut is exposed on the other side.

I spent over an hour pounding that thing and it was very well lubricated. The pipe and donut are very tight and firm. It doesn't appear to be leaking...not yet anyhow.

Should I worry about the seal because it's not seated all around? Or am I OK since it's tight as all heck.

Any advice would be most appreciated!

have you made sure the hub is cleaned out all the way to bottom? Any old lead or oakum or rust build up to prevent the seal from seating all the way around? Debris? One can also squeeze the insert into a cee shape, stick it in the hub, then try to expand it back to a circle.

The hub is clean as a whistle. All the lead and oakum is gone. Corrosion sanded away with emory cloth and then wiped clean with a wet rag.

The insert fit nice and snug into the hub without the PVC but when I put the donut into the hub first I couldn't get the PVC in there - even with chamfered edges and lots of lube.

Best method I found was to put the donut around the PVC and then insert into the hub together. After several attempts, I was only partially successful as described above.

Not the proper way to insert it. If the cast iron was "really" old, it could have a hub which did not conform to the specifications for a compression joint, which would have made it difficult or impossible to insert the pipe after it was in the joint.

hj said:

Not the proper way to insert it. If the cast iron was "really" old, it could have a hub which did not conform to the specifications for a compression joint, which would have made it difficult or impossible to insert the pipe after it was in the joint.

Click to expand...

HJ,

How would you try to insert it?

You can take precise measurements of both the CI and PVC and call Fernco to see what they have for a best fit. Fernco can make 1000s of different donuts and they will make odd ones on demand.