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Plumbing Leak - Lead to Cast Iron

DonCanDo's picture

I almost hate to ask this here because the correct answer is to call a plumber... but... my customer doesn't use this bath and she really would like me to fix this on the cheap, even if it only lasts a year.

So here's the deal.  It's a 4" lead toilet flange/elbow that appears to be soldered to a cast iron nipple that goes into the main stack.  It barely leaks, but she doesn't want to leave a bucket permanently on the floor.

What's the right way to fix this, in other words, what would a plumber do and is there any way to use a repair tape such as this one or this one?

(post #108527, reply #1 of 17)

I've had good luck repairing those connections using epoxy. I gently clean up the face of the hub and the lead, and depending on the size of the void left, use liquid or the kneaded epoxy to repair. It's worked pretty well. If the lead isn't too long or compound, it might be possible to remove it, install a hub-nohub fernco, and put in a CI bend and flange.

(post #108527, reply #2 of 17)

There's "lead wool" that I've read about here - never seen it or used it myself. Just like steel wool, but you pound it into the void, rather than melting it.


(post #108527, reply #3 of 17)

I am guessing the leak is at the lead to cast iron transition.  I have had some luck with plumbers epoxy, comes in a tube that you cut off a piece and knead it.  in desparation I have used silicone and it will hold for a few years, but if it doesnt nothing else will stick to it, so it is definitely a last resort.  I would find the exact crack location and use the epoxy.  I haven't tried any of the repair tapes.

the lead wool mentioned is good when making a joint up which would need poured lead (use with oakum, maybe rtv on top for belt and suspenders), but i don't think it would be useful for your repair.

Hope this helps.  Rich

Hope this helps.  Rich

(post #108527, reply #4 of 17)

Cheap fix - Plumbers Goop.  It is also sold as Shoe Goop.

It is a sticky contact cement like product.  Smear it over the leak and let it setup.

I'm not proud of using it but it has worked for me several times and still holding up for 18 years on a repair very similar to your problem.

(post #108527, reply #5 of 17)

Harveys soil seal.

Liquid sealant... don't know what it is made of, but it works.

(post #108527, reply #6 of 17)

In Mom's house, I'ev whacked the existing lead down 1/2" with a punch ('happened' to have some caulking punchies) and then squirted a tube of silicone over it..  Has held for 6 years with nary a dribble.

(post #108527, reply #7 of 17)

We have the same problem

A plumber is coming to look at it tommorrow

I have wondered if this type of leak is caused from the house moving and settling over the years

(post #108527, reply #8 of 17)

JB Weld.

(post #108527, reply #9 of 17)

Autozone has gastank/radiator epoxy repair putty, 3 $  for a wad about the size of a gherkin.  Works like a charm in no time flat.

(post #108527, reply #13 of 17)

What inna' hell is a gherkin?



(post #108527, reply #10 of 17)

Just repaired on recently.
First I think what you mean is the toilet flange is connected to a lead bend. The factory lead bend is then factory soldered onto a brass ferrule or nipple that is then set in the field into the hub of a cast iron fitting . By set in I mean it predates no hub and was set using yokum and lead. Depending on how involved you want to get and how much room you have , and most importantly you Level of soldering skill this is what i would recommend. Try one of the other suggestions with epoxy type fixes . leave the ceiling open to dry and observe leaks for a two weeks. Be 100% sure it is not leaking from the toilet flange that the toilet is connected to .
you can remove the toilet and flange. cut the lead bend leaving the brass ferrule. then Very Very Very Very carefully , after you have removed any insulation around the area for 18 " removed any flammable debris and then throughly soaked with a spray bottle all joists and plywood do the following . be sure you have a fire extinguisher ready and a helper to be fire watch.
Get a torch and begin heating the lead around the ferrule . the lead is itself looks like a brass ferrule you use for a compression fitting
in shape . begin heating and it will start to flow off the brass then you can heat and scrape off - then after all off one final cleaning and some emery paper. Next go to the plumbing supply house and get a fernco 4x4 or 4x3 depending on lead bend size .
also get a long sweep bend and a new toilet flange .
Depending on where you live and local codes you may be able to use schedule 40 PVC. the coupling goes onto the brass ferrule, the pvc goes into the long sweep that is now you replacement lead bend the lead bend and an extension if needed goes up through the floor to connect to the new toilet flange . flang get screwed to subfloor , place waxring and bolts in place and reset toilet .

That is an overview- You must read and understand what you are doing - do not proceed with cook book type approach
Hope this helps

(post #108527, reply #11 of 17)

I understand the procedure.  Thanks for a clear description.  I will not undertake that level of repair, but it's good to know how it would be done.

I'm actually surprised by how many people have had good luck with epoxy and repair tape.  I will probably take that route.  If it doesn't work, then it's time to call a plumber.

Thanks to all for the suggestions.

(post #108527, reply #12 of 17)

3m marine adhesive and sealant.



"When the spirits are low, when the day appears dark, when work becomes monotonous, when hope hardly seems worth having, just mount a bicycle and go out for a spin down the road, without thought on anything but the ride you are taking." — Sherlock Holmes, 1896



"When the spirits are low, when the day appears dark, when work becomes monotonous, when hope hardly seems worth having, just mount a bicycle and go out for a spin down the road, without thought on anything but the ride you are taking." — Sherlock Holmes, 1896

(post #108527, reply #15 of 17)

Best of luck with it - I would do the same with the simplest of solutions first. with todays adhesives and repairs compounds It is the best first choice of repair .


(post #108527, reply #16 of 17)

And an update...

I was hoping to report on the success/failure of the pipe tape repair kit, but as soon as I started cleaning the pipe in preparation for the repair, it began falling apart.  There were several large holes so on to plan B.

I duct-taped it to slow the flow of water and the homeowner arranged for a plumber to come next week.  He'll be replacing everything from the brass nipple to the toilet flange.  It's the right thing to do.

(post #108527, reply #17 of 17)

This isn't hard. But it maybe a bit messy.

You can buy, "no-hub" rubber couplings. These things are great and legal.

They come in all kinds of sizes, and adaptations. Probably found at Lowes, at least their at our Lowes.

Most cases a plumber will remove the bad section of cast. Replace it with an equal 'inside' diameter plastic pipe. Use a no-hub on each end.

The clamps are supposed to be torqued to 65 inch lbs.

No torque wrench? Just snug it up and tighten more if needed.

If it's by a toilet flange,.... well let me know and I'll tell you about that one too.

Good luck.





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I believe George Burns said something to that effect.