Tightening flange to tub boot, how much?

[AH81]

Hello,
I have been a long time reader of this forum and have found it very helpful, thank you.

With information Ive read here I have been able to rebuild my 1959 bathroom stronger than before, with plumbing to code, and a new Kohler bellwether cast iron tub. The joists and subfloor are plenty strong for a cast iron tub, with feet resting over the joists. I have made a lot of progress while spending a lot of blood, sweat, tears, and time.

Tub is a cast iron Kohler Bellwether.
Waste overflow is kohler's all brass K-7160-TF

Ive read a number of threads on installing the flange and tub boot and have a generalized idea of what to do. Also purchased a Smart Dumbell to tighten the flange.

My question and concern is, how tight do I tighten the flange? My fear would be cracking or chipping the porcelain. Taken a lot of time to get where I am and dont want to screw it up.
Thanks
Adam

 

[Terry]

The overflow comes with a rubber washer that slips between the tub and the shoe of the drain. I put some putty on the flange and thread it down, snugging it up with the dumbell. I put a wrench on it and snug it pretty good. You don't have to Tarzan the thing though. You're just clamping the fittings together.

 

[Sponsor]

 

[Scott D (CA)]

What Terry recommends ought to do it. When you get the W & O installed, you should fill the tub with water up to the overflow. The overflow is more difficult to make water tight than the drain.

 

[AH81]

Right. I have not taken the Tarzan approach. If anything Im being too cautious. I'm used to working with torque values.

If I get it hand tight with the dumbell, how much of a turn would you do with a wrench? 1/4 turn? Ever heard of the porcelain on a cast iron cracking or chipping from over tightening?

Im also learning that too much putty can be a problem. Thinking putty the diameter of a pencil on the bottom of the flange.

 

[Scott D (CA)]

A bead of putty about 1/2" should be about right. If you overdo the putty a little, it will still work it's way out of the joint. Snug down the dumbbell until the putty is hardly noticeable between the tub and flange.

 

[AH81]

Found if I overdo the putty is gets pushed down onto the threads and rubber gasket.

 

[AH81]

Thanks for the help. If you all think of anything else. I appreciate it.

 

[Terry]

The putty hardly matters. It's the compression of the rubber seal below that does it.

 

[Scott D (CA)]

Terry
It may not matter much. But, try it without putty and see how it goes.

 

[Terry]

Terry
It may not matter much. But, try it without putty and see how it goes.

I have. The putty isn't needed.

 

[FullySprinklered]

In woodworking you can screw it or glue it or peg it or dovetail it or clamp it. The more you do the better long term.
On a tub drain you've got the rubber washer on the bottom of the tub and the screw-in drain preloaded with putty on the top side. It's good insurance. Overtighten the tub drain and the washer on the bottom may egg-out and leave an eight-lane highway for a leak later on, after the putty dries out, ten years down the road. I always ask people how old the house is when they have a mystery stain on the ceiling below an upstairs bathroom. Sometimes it's meaningful, sometimes not. It's a crapshoot every time.

 

[AH81]

Thanks for the reply guys. I think its a matter of doing it once vs. years of experience.
Thanks for the help. I do appreciate the input.