Hi . . . I'm replacing my old cast iron tub with a whirlpool tub. The old drain was a 1 1/2" brass tube tucked into a 4" cast iron drain pipe (with hub), packed with what might be oakum. The seal was fibrous and waxy when I cleaned out the drain, and that's not MY hair :)

What's the best way to make the seal between the new 1 1/2" pvc drain tube and the cast iron drain?

Thanks much,

Nancy

If you have enough room you may Caulk in a 4 X 1 1/2" cast iron threaded reducer and install a galvanized, (*or convert to PVC) nipple a topped off with a compression fitting to connect to the tub drain. If you don't have the room to do that you can pack in oakum like it was before and then pack it down withr lead wool. Good luck, Tom

Thanks so much, Tom. There isn't much room at all, so it looks like I'll be packing it like it was before. This is my first real plumbing installation (just the odd toilet fix, faucet replacement kind of stuff, before) and it's nice to have the support of experts.

Take care,

Nancy

Do you still have your old tub?
C

There isn't much room at all, so it looks like I'll be packing it like it was before.
NO!! Bad idea! I should have snapped earlier that your old tub wasn't trapped. It sounds like this was a old toilet installation that someone "jacklegged" into a Cast iron quarter bend. If you connect the same way you will be allowing sewer gas to enter your home as it has been ever since the toilet was converted. This is not healthy and should be repaired ASAP. The quarter bend will have to come out and a 4 X 2" PVC reducer joined on the cast iron using a shielded coupling. This converts you to 2" PVC. And from there you can install a PVC trap and raiser. Good luck. Tom
Hey! Nothing ever turns out simple does it?

Use Flex Seal coupling for your connection. Make sure tub is trapped. Also, jacuzzi tub drain should be 2" and vented.

Use Flex Seal coupling for your connection. Make sure tub is trapped. Also, jacuzzi tub drain should be 2" and vented.
Milo,
Nancy has 4" cast iron that has to be converted to 2" PVC before she can make any connection. Then she has to install a trap and raiser. Why a Flex-Seal coupling? What's wrong with a regular hook up? Regards, Tom

Tom, she asked: "...What's the best way to make the seal between the new 1 1/2" pvc drain tube and the cast iron drain?. " I esponded directly to that question...

Milo,
Did you not read,
The old drain was a 1 1/2" brass tube tucked into a 4" cast iron drain pipe (with hub), packed with what might be oakum. The seal was fibrous and waxy when I cleaned out the drain
And you suggested,
Use Flex Seal coupling for your connection. To what? The 4" quarter bend? Get real! She has a lot of work to do before she can even address connecting the tub waste. Tom

Tom, I understand...

I repeat one more time her question: "... What's the best way to make a seal.. "

But Milo, you got to use your head when you answer these questions. As the job stands right now she can't connect to squat until she converts to 2" PVC. Sure, you answered her original question, but did you help her to get to the point where she could connect the waste to the trap? Sometimes you have to " interpret" the askers question and respond accordingly. You're fairly new here, it takes a little time to settle in. Just stop and think a little and then give the best advice you have to address the situation. Put yourself in the askers place and thinlk outside of the box once in a while.
Regards, Tom

Tom: sure... and thank you for pointing this out to me

No problem Milo,
You give good answers. It's just that sometimes I have a little trouble getting you UPC guys to think beyond the ridged code that you work with and bring you in line with the rest of us. Ya just can't use one code to cover all the questions that we're asked. Keep up the goodwork, you're doing just fine. Tom