can you disconnect old cast iron fitings?

Old 01-02-05, 06:59 PM
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Question can you disconnect old cast iron fitings?

I am renovating a bathroom in my 80 year old house. If I could just disconnect the 4" cast iron pipe from a joint on the waste stack, and reconnect PVC, it would make things MUCH better. I assume it is oakum with lead melted in. I'm thinking drill as much out, and melt the rest with a torch. If this is the case, what kind of torch should I use? And how would I re-connect PVC- glue/ cement? Any ideas would be great.
Old 01-02-05, 07:12 PM
majakdragon's Avatar
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stvstwl, Welcome to the DIY Forums.
If at all possible, cut the cast iron with a set of chain snappers and leave a stub. Then you could make a transition with a no-hub clamp that goes from cast iron to PVC. This would keep you from melting the lead and messing with it. You can find these clamps at home centers or plumbing supply stores. They are rubber with 2 stainless steel clamps. Also called Mission Fittings. Good luck with your project.
If you HAVE to melt the lead, a propane torch will do it. Bernz-o-matic type.
Old 01-04-05, 03:20 PM
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Stvstwl, I prefer the idea of drilling it out, first thing to know is take your time. Use a 1/4" drill bit and go completely around the hub drilling straight in. Make the holes as close together as possible. Second, start at any hole and drill in at a slight angle, back out and drill in the opposite direction in the same hole. Go around the hub in this manner until you have returned to your starting point. Take an old screwdriver and pry out what is left of the lead. The oakum will easily follow the section of pipe you remove with little effort. Purchase a Tye-Seal Gasket from a plumbing supply house and place it in the hub. (PVC has a slightly larger outside diameter then cast-iron ) The section of pvc you install into the gasket will need to be filed off on the end being inserted into the gasket so the out side edge of the pipe is smooth with a slight angle. Apply some dish soap or any form of lubricant, make sure the pipe is level or square with the hub and shove it in. Sometimes it can be a challenge to slip this first piece in but it will fit. I have seen some plumbers trim the inside ribs of the gasket to make this part easier but I always wonder about the quality of the seal. My concern about cutting (especially with snap or ratchet cutters) is that this is an old line. More often then not it will crush rather then cut and now your replacing another fitting and pipe section. Well as you asked, Its just my opinion. Good luck which ever direction you go.

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