Connect PVC to Cast Iron

[happygene]

(edit - Pardon me, but the head topic page said LazyPup replied a few hours after I posted, but I cannot find it[?] - If this is answered somewhere else, I would gladly look there)

Hi LazyPup,
I'd like to know a little more about this epoxy/oakum approach as I think it addresses my need.

Currently I have a 3" copper pipe coming down (inside the wall to the lower floor from the first floor toilet) into the bell flange of a 3" (I think...maybe 4?) cast iron pipe that's nearly flush with the floor. The copper is leaded into the bell flange.

Most of the copper has rotted away and just to get things flowing again, I only replaced the rotted section with PVC and compression sleeves. But before I button the wall back up, I really want to get rid of the remaining copper pieces as I fear that they will rot away eventually as well.

[u]Question/clarification 1</u>: What is the smartest way to remove the copper and lead from the bell flange without damaging myself or the bell flange in the process? Left to my own devices, I'd probably try to crush the copper, then try to twist it out. If the lead remained, I'd use a cold chissel...

[u]Question/clarification 2</u>: How clean do I need to get the inside of the bell? Are there any steps required to remove rust/oxidation beyond wire brushing? Should I perhaps treat the lip of the bell with a "rust conversion" type coating?

Thanks in Advance,
happygene

quote:Originally posted by LazyPup

Fernco makes a rubber gasket for that purpose but i dont really care for them. I prefer to clean out the hub thoroughly, insert the PVC into the hub, then pack the hub 1/2 full with oakum and fill the remainder of the hub with plumbers expoxy in the same manner as lead was originally used.

The plumbers epoxy is a two part putty type epoxy, one part white and the other part black that you must knead together until is is an even grey color to activate the catalyst and resin.

You can buy the plumbers epoxy at Lowes, Home Depot and most hardware stores.

You can buy oakum in nearly all hardware stores. The make two types, plain oakum and oil impregnated. I prefer the oil impregnated type when i can get it.

Oakum will look like a piece of frayed hemp rope about 1" in diameter and usually comes in lengths of 2 to 3ft. You wrap it around the pipe and pack it into the hub.

[LazyPup]

I appologize for the delay in my answer, We have been having a lot of problems with our cable internet connection, hopefully it is finally straightened out.

Now to answer you question, how to get the copper pipe and lead joint out of the cast irom pipe hub.

I would first cut the copper off close to the hub (leave about 1/4 to 1/2" sticking up.) You may then be able to use a punch to collapse the copper inward until you can pull it out, but in all likelyhood the lead is sticking to the copper in the same manner as solder would so you may not be able to pull the copper out.

You may try to use a minihacksaw to make a vertical cut in the copper.

Then use an electric drill with a 3/8 bit drill two or three holes vertically down into the lead close together to make a starting point. The idea is to try to cut a vertical slit in the lead. Once the lead is cut you should be able to use a large flat screwdriver or a prytool to pry the lead out of the hub. (I often use an old automobile tire tool that has a pointed end to fit into the holes in the lead)

With a bit of effort the lead should pry right out of the hub.

Once you have the lead out, use your screwdriver or pry tool to remove the oakum that is below the lead (It will look like a wad of frayed hemp rope, probably black with age.)

Once you have the lead and oakum removed clean the inside of the hub with a wire brush. Cast Iron is naturally rough so you will not get it clean and shiny, just be sure to get as much of the loose scale and rust as you can. Wipe the inside of the hub with a rag, and you will be ready to begin making your new joint.

When the PVC is fit into the hub you should have about 3/8" clearance between the outside of the PVC pipe wall and the Cast Iron Hub inner wall. (You may find that a PVC coupling will fit in and leave the correct clearance, if so, insert the coupling and set it in place, then you can glue your new PVC into the coupling.)

With the PVC in the hub all the way to the bottom of the hub, Pack Oakum between the PVC pipe outer wall and the cast iron hub inner wall in the same manner as it was done for the original lead joint. Use a narrow punch of some sort to pack it tightly into the hub until the hub is half full from the bottom.

You can then fill the remaining portion of the hub with plumbers epoxy or there is another product that is difficult to find but works excellant. It is called "Black Swan Iron Paste" Made by Black Swan Mfg.Co, Chicago, Ill. 60651

Black swan iron paste is a type of plastic liquid lead that is made for making joints in cast iron pipes. I found it at my local hardware store. About $6.98 for a quart. The quart is the smallest container I have seen it in and a quart will be plenty to make a half dozen such joints in 3" cast iron pipe.

In the attached illustration you will see how to use a drill to cut the lead out.

[happygene]

Hey LazyPup,

No appologies necessary! To know as much as you do, I'd
speculate you have a day job!

I am delighted with this removal advice as it will most certainly
save me pain and swearing!!! I usually zen my way through jobs like
this and get there eventually, but it's great to have this kind
of trick of the trade insight.

Thank you so much for sharing your knowledge!

--happygene

quote:Originally posted by LazyPup

I appologize for the delay in my answer, We have been having a lot of problems with our cable internet connection, hopefully it is finally straightened out.

Now to answer you question, how to get the copper pipe and lead joint out of the cast irom pipe hub.
{snip}
With a bit of effort the lead should pry right out of the hub.

[LazyPup]

I just realized that the illustration might be a bit confusing..Drill the holes straight down in the lead from the top of the hub,,do not drill through the hub.

[happygene]

No Worries LazyPup! (at least not for me)
I understood exactly what you meant. Besides, I imagine drilling through the iron might be a bit difficult!

quote:Originally posted by LazyPup

I just realized that the illustration might be a bit confusing..Drill the holes straight down in the lead from the top of the hub,,do not drill through the hub.

Well, it's February (2006) and I finally got around to tackling this job! The removal part was a bit tough. The copper was joined to the iron with a bronze adapter. It was well stuck to the lead! It took about 20 minutes of beatin-bangin-and-swearin to get it out, it would have taken me hours without LazyPup's tips!

To seal the joint I used a product called Plastic Seal by Hercules (PN 25-215) which I got at my local contractor supply house for about $10 for a caulking tube container. It was the consistency of very thick toothpaste, dried to good tack in about 5 hours. Also used the union to make the 3" plastic fit the bell better. I actually sealed that joint last after I had everything else (2 T's and 2 fernco-like flex unions) assembled - I needed the slop. I was more than willing to pay extra to have the goop in a tube, it stuck like mad to anything! After it dried it was really stiff, but rubber like too.