Attaching PVC to Cast Iron Clean Out

Jerry1

Jerry1

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I’m trying to figure out how to attach a PVC pipe to my existing sewer clean out.

The treads are rotted out at this point so I cannot just buy/use a typical screw in clean out plug. I did but something that works to seal it which works fine. This isn’t the exact model, but it’s similar:

https://www.homedepot.com/p/JONES-S...r-Cast-Iron-and-Plastic-Pipe-T31004/100141500

The reason I want to attach some PCV is because I want to raise the opening up a couple feet to make it easier to use. I drain the excess water from my pool into the sewer. If I can raise it up a bit and put a better (easier to put on and take off) cap/plug . . . on it, it would work better for my needs.

Problem is that the opening is 3-3/4 inches. And, while there’s a lip on the top outside of the opening, it’s not enough to put a outside diameter rubber reducer coupling on it. So I need something that will go inside the opening and create a reasonably good seal. The clean out is right next to my house, under an eve so exterior water is not really a problem.

Here’s a picture of the clean out. It looks like the cast iron is in worse shape in the picture than it actually is. It does have some rust but the picture makes it look like the rust is about ready to scale off inside the pipe. Actually, it’s pretty solid for 65 years old.

33319-albums249-picture2680.jpeg


Any ideas how to make this connection? I’d be happy with either 4 inch or 3 inch PVC.
 
The OD of 3" PVC should be a pretty close fit. Maybe wrap a little electrical tape. I'd put a 3 inch coupler on and then as much extension you want in the pipe and as much rise as you want on the other side of the coupler.
 
calmloki said:
Fernco fitting. Have had some exposed to the sun and weather for over ten years w/o issue. Does that white collar come off, leaving you just a cast straight pipe?
Click to expand...

I'm not sure. I'll tap on it a little and see if it moves. Obviously, I don't want to break anything and turn this into a project I'm not ready/able to handle. A straight pipe would be a lot easier to deal with.
 
OD of 3" PVC is 3.5" (I think). So that would leave an 1/8" gap. I'd attach some 1/8" thick weatherstripping to the outside of a piece of 3"pvc. Push it down into the clean out and fill the 1/8" gap from the weatherstripping on up with hydraulic cement. The weatherstripping will prevent the hydraulic cement from falling into the cleanout. And it should be fairly solid and waterproof when the hydraulic cement dries.

The Fernco fitting would work if the sizes work, but I don't think that the size will work out.
 
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there are ferncos and mission band type fittings that can manage those sizes.
 
Somehow I just lost everything I was going to post :mad:
Too late to re-do.

In your pic I think I'm seeing a cleanout adapter that was Oakum and leaded into a hub end. To verify its a hub end, dig down in the soil just to one side of it. If it is a hub, it should go straight down a couple inches, and then with a smooth curve, it will turn inwards to the body.
Years ago, I had to handle this situation under a house in a crawlspace with only room to squat, with temps in the 30s.
 
Ronstar said:
OD of 3" PVC is 3.5" (I think). So that would leave an 1/8" gap. I'd attach some 1/8" thick weatherstripping to the outside of a piece of 3"pvc. Push it down into the clean out and fill the 1/8" gap from the weatherstripping on up with hydraulic cement. The weatherstripping will prevent the hydraulic cement from falling into the cleanout. And it should be fairly solid and waterproof when the hydraulic cement dries.

The Fernco fitting would work if the sizes work, but I don't think that the size will work out.
Click to expand...

The old way to "weld" iron pipe was to fill the gap with iron filings and pour in sulfuric acid. I have never done this but I have seen a procedure in a very old "Handbook for Mechanical Engineers." You may be able to weld in a modern fitting this way.
 
You may need to cut off the top connector so that you have straight Cast Iron pipe and then use a rubber connector (Fernco etc.) to mate with the PVC.

I would probably start digging down to see what you have. It may simplify the issue. In my case I found the CI pipe loosely fit into Orangeburgh "pipe" (ie the paper/tar material that was popular mid century before the age of Plastics).


-gauss
 
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gauss said:
You may need to cut off the top connector so that you have straight Cast Iron pipe and then use a rubber connector (Fernco etc.) to mate with the PVC.

I would probably start digging down to see what you have. It may simplify the issue. In my case I found the CI pipe loosely fit into Orangeburgh "pipe" (ie the paper/tar material that was popular mid century before the age of Plastics).


-gauss
Click to expand...

That makes sense but the current plug I have is working fine. This is just for convenience. Therefore, I’m not going to do anything that would cause this to grow into a bigger job. There’s bushes near this and it’s pretty old. Not something I’m willing to get into right now. I’ll just keep using the plug I have rather than make a mess.

The gas company was out last year and before they horizontally drilled, they mapped out all utilities. In that process, they scoped out my drain. They said it looked good (no cracks and no roots). So, a light touch is in order here given that the pipe is over 65 years old. Learned a long time ago to leave well enough alone.
 
How about this?

https://www.homedepot.com/p/3-in-x-...ser-Reducer-Coupling-PVC001021400HD/203391397

Stick the 3 inch side in your current pipe, use 4 inch PVC above. Put some calk/sealer/cement around the lip overhanging the metal to keep it in place.

Then this:
https://www.homedepot.com/p/NDS-PVC-S-D-Female-Cleanout-Adapter-4-in-Hub-X-FPT-4P11/100203709

and this:
https://www.homedepot.com/p/NDS-PVC-S-D-Cleanout-Plug-4-in-MPT-41P8/100164594

then use a couple feet of 4 inch PVC to connect the first two - raising it how you want.
 
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That may work. I didn’t think about the 3” pipe having on outside diameter of about 3-1/2 inches. I’ll measure that this weekend when I go to HD. Probably could get some rubber gasket material to fill I the gap so that I really don’t have to do anything permanent with the original pipe.
 
Well thanks for all the advice but the answer ended up being right under my nose. After njhowie posted, I looked at my current plug. I was going to take the rubber gasket off my existing plug to see if it would make up the gap to put in a 3” adapter. I do think that would have worked. Here’s a picture of my current plug. They call them test plugs because their typical use is to plug a pipe and do a pressure test.

33319-albums249-picture2681.jpeg


Well, before I ruined my current plug, I went online to buy another one (backup) and in reading the specifications it said that the top of the plug can be cut off in order to fill the pipe you’re testing (the stem is hollow). So I just went out and checked and sure enough, the threads on the stem are garden hose threads. All I need to do is cut off the top of the stem and hook a couple feet of garden hose to it in order to make it easy to make the connection to drain my pool.

It took a different path than expected, but thanks for leading me to a great answer to my problem. Not only a better solution, but easier and cheaper. :dance:
 
Jerry1 said:
...

It took a different path than expected, but thanks for leading me to a great answer to my problem. Not only a better solution, but easier and cheaper. :dance:
Click to expand...

Sounds good! After you explained you didn't want to mess with the existing pipe, for fear of creating another problem (smart), I was thinking about that plug, and if you could somehow drill it out to provide the drainage you need.

Looks like it was designed in - and if garden hose size is all you need, looks like an almost perfect solution for you.

I rarely win against the plumbing gods, but it does happen occasionally. Congrats!

-ERD50
 
Jerry1 said:
Well thanks for all the advice but the answer ended up being right under my nose. After njhowie posted, I looked at my current plug. I was going to take the rubber gasket off my existing plug to see if it would make up the gap to put in a 3” adapter. I do think that would have worked. Here’s a picture of my current plug. They call them test plugs because their typical use is to plug a pipe and do a pressure test.

33319-albums249-picture2681.jpeg


Well, before I ruined my current plug, I went online to buy another one (backup) and in reading the specifications it said that the top of the plug can be cut off in order to fill the pipe you’re testing (the stem is hollow). So I just went out and checked and sure enough, the threads on the stem are garden hose threads. All I need to do is cut off the top of the stem and hook a couple feet of garden hose to it in order to make it easy to make the connection to drain my pool.

It took a different path than expected, but thanks for leading me to a great answer to my problem. Not only a better solution, but easier and cheaper. :dance:
Click to expand...

Do you drain your pool with a sump pump? (I do) My sump pump has male threads I screw the female fitting of a garden hose to - which means I have male threads on the hose at the output side. Do you have a double female connector hose? If you don't want to elevate your existing 4" pipe why not just use the plug you bought and remove it to stuff a foot or so of the drain hose down the pipe on the rare times you drain the pool. It won't leap back out and I've noticed no odor doing that.
 
calmloki said:
why not just use the plug you bought and remove it to stuff a foot or so of the drain hose down the pipe on the rare times you drain the pool. It won't leap back out and I've noticed no odor doing that.
Click to expand...

That’s what I’ve been doing, but it’s behind so bushes, so not easy to get to, it’s on the ground, so I have to get dirty kneeling to get the plug out, and, with the pipe being rusty, the plug is getting scratched an will deteriorate over time.

I can easily fabricate a hose (double female connector) that I can have easy access to and just connect it now that I have this option. Bonus is that the plug stays put and I can connect quickly.
 
Jerry1 said:
I’m trying to figure out how to attach a PVC pipe to my existing sewer clean out.
Click to expand...

I couldn't see your photo for some reason, but when I replumbed my inlaws house, I used a grinder with a cutoff wheel to cut their 4" cast iron pipe (behind any fitting hubs). Then I slid a full 10 foot length of 3" PVC inside the cast iron (it was old and rusty and ran under the carport slab), and used a reducing rubber coupling like this:

https://www.homedepot.com/p/Fernco-...chanical-Flexible-Coupling-P1056-43/100372297

It's been working fine for 15-20 years now with no issues.
 
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