Hi! Replaced the cast iron drainage system with PVC in a house built in the 1920's. The new horizontal neoprene to cast iron joint has a very small leak that we believe is due to the irregularity of the old cast iron surface. Is there a way to smooth the cast iron surface or add some type of sealant underneath the neoprene boot to provide a leak proof seal? Thanks

Hi kim and welcome, have you tried to tighten the clamps a little?

As far as smoothing the CI, you could use a file to knock some rust off where the clamps go. Good luck

PT gave good advice! When needed, I use a hand file and smooth the pipe surface when dirty.

When there are raised letters (older cast iron pipe) that are in the area that I want to clamp I sometimes use an angle grinder and a metal cutter wheel (and safety goggles) to smooth the letters flush with the pipe and then install my clamp.

Mark

Yep, file and/or grind but you can also use plumbers grease if this still leaks. Usually just tightening is what's needed

We tightened it, can you tighten it too much? Thanks for the direction- kb

Try to tighten some more and check if the leak stops, If not You need to remove the neoprene boot check the surface of the cast iron if it needs cleaning clean it as the bove experts suggested, use some plumbers grease and tighten the clamp, check if it work, Thanks.

John

I will do,

Thanks kb