I have an older home that has a vented stand cast iron plumbing (4-6" diameter), and the joints are sealed with lead. I need to rotate one tee joint (runnuig vertically). Do I have to heat the lead to a molten state to allow rotation? I have never worked with lead sealed pipe and while this seems logical, I just want to check with someone who has the experience. Thanks.

I have an older home that has a vented stand cast iron plumbing (4-6" diameter), and the joints are sealed with lead. I need to rotate one tee joint (runnuig vertically). Do I have to heat the lead to a molten state to allow rotation? I have never worked with lead sealed pipe and while this seems logical, I just want to check with someone who has the experience. Thanks.

" Do I have to heat the lead to a molten state to allow rotation?"
No, although that would do it. When I am faced with this problem I get a purchase or leverage to where I can start to rotate it back and forth to loosen the lead seals. Just rock the tee back and forth and it will go a little farther each time. When it reaches the desired position you will have to recaulk the lead joints. Good luck, Tom