Flexible WC connector into cast iron, best practice?

[tonton]

I have a McAlpine flexible connector going from the toilet into the cast iron stack. The cast iron is approx 3.5” internal diameter and has a short 200mm horizontal sloping run before joining the building's main vertical pipe.

The flexi connector is like the one pictured, except mine does not have the fins on the outlet side - it's smooth. It doesn't insert very far into the cast iron collar (if that's the right term. Bell?), no wet sealant has been used and it looks like water is tracking back up the plastic and rusting the collar. What is the best way to fix this?

1. Extend the plastic connector's outlet side so it inserts into the cast iron a bit further, and use a wet sealant (what type?).

Or

2. Replace the flexible connector with a finned one.

3. Something else?

 

[tonton]

 

[johnny2007]

Looks like it's all the way into the cast iron collar.
If it leaks, replace with same one.
Usually they leak when disturbed and you can never stop the leak permanently.
A lot of silicone or lsx will temporarily work, but still needs a replacement new connector.

 

[tonton]

Looks like it's all the way into the cast iron collar.
If it leaks, replace with same one.
Usually they leak when disturbed and you can never stop the leak permanently.
A lot of silicone or lsx will temporarily work, but still needs a replacement new connector.

It definitely can't be pushed in any further. This red section is wide which prevents it going further.

I'll look up LSX, thanks.

PS I looked at the McAlpine flexi connectors that Sfix stock, and they all have fins on the outlets. Perhaps they don't make the smooth ones any more.

 

[Deleted member 267285]

Use an extension B multikwik or McAlpine equivalent and use another connector into it? Maybe the fins are stuck inside the cast iron? They’re usually sold with them

 

[tonton]

Use an extension B multikwik or McAlpine equivalent and use another connector into it? Maybe the fins are stuck inside the cast iron? They’re usually sold with them

I'll check out those extensions, thanks. I've had the whole thing out of the cast iron, definitely no fins on this one.

 

[Deleted member 267285]

I've had the whole thing out of the cast iron, definitely no fins on this one.

Ok, no worries. As they’re movable fins, thought it may have been a tight fit and left behind.

 

[johnny2007]

I'll check out those extensions, thanks. I've had the whole thing out of the cast iron, definitely no fins on this one.

They've fallen into the sewage.
New one needed, with fins!
Check size of cast iron pipe, some of them are 3.5"

 

[Madrab]

I'd take that out - see what the diameter of the cast is and then seal in a piece of plastic pipe into it - be it a 4" piece of plastic or a 31/2" piece of extension. Clean out the cast collar and get the inner surface as clean as possible. Get some silicone adhesive (not sealant) and smooth coat the inner surface to provide a key and let that set for a hour - then coat the outer surface of the pipe that will be inserted and push it home - smoothing out the excess. Let that set. You then have a log term, clean, sized and re-usable insert for any standard connector.

If that flexi has been used just to get past the awkward angle to join the soil pip/pan connector to the right, to the cast then be careful it doesn't become a collecting point for solids if the fall isn't adequate, can't quite see from the pic's angle.

 

[tonton]

I'd take that out - see what the diameter of the cast is and then seal in a piece of plastic pipe into it - be it a 4" piece of plastic or a 31/2" piece of extension. Clean out the cast collar and get the inner surface as clean as possible. Get some silicone adhesive (not sealant) and smooth coat the inner surface to provide a key and let that set for a hour - then coat the outer surface of the pipe that will be inserted and push it home - smoothing out the excess. Let that set. You then have a log term, clean, sized and re-usable insert for any standard connector.

If that flexi has been used just to get past the awkward angle to join the soil pip/pan connector to the right, to the cast then be careful it doesn't become a collecting point for solids if the fall isn't adequate, can't quite see from the pic's angle.

Thanks, that sounds good. The cast iron is 3.5” internal. I hope I can buy just a short length of 90mm plastic pipe. I assume I should use plain pipe, rather than something with a flared end.

The fall of the flexi is borderline, I'll need to check. I'd have to raise the toilet to fix that?

 

[Madrab]

The cast iron is 3.5” internal. I hope I can buy just a short length of 90mm plastic pipe

(edit) As suggested -

McAlpine 4 inch to 3½ Pan Connector Reducing Extension

McAlpine 4 inch to 3½ Pan Connector Reducing Extension. This reducing extension piece will fit on to standard 4 inch toilet pan connectors and fit 3.1/2 inch soil pipe.

www.plumbers-mate-sales.co.uk

 

[denso13]

The cast iron is 3.5” internal. I hope I can buy just a short length of 90mm plastic pipe

Use an extension B multikwik or McAlpine equivalent

 

[tonton]

(edit) As suggested -

McAlpine 4 inch to 3½ Pan Connector Reducing Extension

McAlpine 4 inch to 3½ Pan Connector Reducing Extension. This reducing extension piece will fit on to standard 4 inch toilet pan connectors and fit 3.1/2 inch soil pipe.

www.plumbers-mate-sales.co.uk

Do you recommend putting the silicone adhesive on the finned section of the extension, or just the smooth parts and leave the fins alone?

 

[Madrab]

Clean out the section of cast and see how tight the finned extension is to fit - if it's tight enough you won't actually need any silicone. If it's too loose then I'd use a 4" first and only if all else failed then then adhesive.

The reason for use a piece of 31/2" into the cast would be to give a nice smooth pipe wall for that extension to fit into nicely. That would require a piece of 3.5" inch first tho.

 

[denso13]

Do you recommend putting the silicone adhesive on the finned section of the extension, or just the smooth parts and leave the fins alone?

No, maybe some lubrication, but not silicone.