# Sealing a conduit



## Chris1971 (Dec 27, 2010)

We have an underground conduit that goes from a basement to the exterior of a building that we will abandon. We will remove the unused conductors. I'm looking for a sealant that would be good to seal the interior of the pipe to prevent water and moisture penetration. I think poly water makes something but, I can't remember exactly?


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## Elephante (Nov 16, 2011)

I usually spray foam it to death on both sides, but I think they sell special sleeves that compress to the conduit and concrete. I forgot who makes it.


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## Jlarson (Jun 28, 2009)

Put a PVC cap on each end.


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## erics37 (May 7, 2009)

Elephante said:


> I usually spray foam it to death on both sides, but I think they sell special sleeves that compress to the conduit and concrete. I forgot who makes it.


Link Seal?


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## Elephante (Nov 16, 2011)

http://www.polywater.com/FSTad.pdf


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## Elephante (Nov 16, 2011)

erics37 said:


> Link Seal?


Yea that's it never used it. I think the OP wants to seal inside the old conduits. Misunderstood him.


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## Chris1971 (Dec 27, 2010)

It's an old metal conduit we would like to seal the inside to prevent water from coming into the building. Conduit will be abandoned.


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## 360max (Jun 10, 2011)

http://www.bptfittings.com/catalog/CatalogFamily.aspx?CategoryId=10&FamilyId=266


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## erics37 (May 7, 2009)

Chris1971 said:


> It's an old metal conduit we would like to seal the inside to prevent water from coming into the building. Conduit will be abandoned.


Is it rigid with threads? You could get a threaded cap and spin it on there.


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## Chris1971 (Dec 27, 2010)

360max said:


> http://www.bptfittings.com/catalog/CatalogFamily.aspx?CategoryId=10&FamilyId=266



Great but, probably won't stop water from entering conduit.


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## Jlarson (Jun 28, 2009)

Oh, foam each end then cap it if it has threads, if not find a pvc cap that can be tapped on. If you ever need to reuse it clean the foam out with carb cleaner.

If its a big pipe stuff some news paper in before foaming.


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## Chris1971 (Dec 27, 2010)

erics37 said:


> Is it rigid with threads? You could get a threaded cap and spin it on there.



It's actually an old piece of EMT. Why they buried EMT is anyone's guess?


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## erics37 (May 7, 2009)

Chris1971 said:


> It's actually an old piece of EMT. Why they buried EMT is anyone's guess?


Yeah sooner or later it'll just rust out and get water in it anyway.

Hell just put a piece of plastic wrap over the end with a rubber band, like a ******* condom.


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## Chris1971 (Dec 27, 2010)

Found it.:thumbsup:

http://www.polywater.com/ductseal.html


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## Jlarson (Jun 28, 2009)

erics37 said:


> Yeah sooner or later it'll just rust out and get water in it anyway.


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## HARRY304E (Sep 15, 2010)

Chris1971 said:


> We have an underground conduit that goes from a basement to the exterior of a building that we will abandon. We will remove the unused conductors. I'm looking for a sealant that would be good to seal the interior of the pipe to prevent water and moisture penetration. I think poly water makes something but, I can't remember exactly?


 Spray foam:thumbsup:


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## frenchelectrican (Mar 15, 2007)

If ya going to abandon that conduit which it is no longer used at all and will never use again., 

This what I useally do is either use the expanding marine grade foam or use the hydrallic cement that stuff will plug up the conduit pretty nice.

Merci,
Marc


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## mikeh32 (Feb 16, 2009)

get AB foam.

just check what that poly **** is, same stuff


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## BBQ (Nov 16, 2010)

Screw the foam, as Marc mentioned just get some hydraulic cement. 


http://www.quikrete.com/productlines/HydraulicWaterStopCementPro.asp


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## chewy (May 9, 2010)

Id just caulk whatever kind of stuff was in my gun then hammer the conduit closed and over on itself.


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## Jlarson (Jun 28, 2009)

If it really is EMT I too would cut it off and fill it with hydraulic cement and forget I ever saw it.


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## BBQ (Nov 16, 2010)

Jlarson said:


> If it really is EMT I too would cut it off and fill it with hydraulic cement and forget I ever saw it.


It is also cheaper then foam.


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## chicken steve (Mar 22, 2011)

wouldn't 230.8 have it already sealed? ~CS~


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## BBQ (Nov 16, 2010)

chicken steve said:


> wouldn't 230.8 have it already sealed? ~CS~


Yeah, and those under 21 never drink alcohol. :laughing:


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## chicken steve (Mar 22, 2011)

heaven forefend BBQ! :jester:~CS~


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## Big John (May 23, 2010)

I also agree with hydraulic cement. 

Some jackass thought would be a good idea to put a conduit at the bottom of a cooling-water canal. Worked fine until it didn't and the conduit began to drain the canal into the electrical room. I used compressed air to force hydraulic cement into it, and it's still holding back 25' of head pressure as we speak.


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## LJSMITH1 (May 4, 2009)

BBQ said:


> Screw the foam, as Marc mentioned just get some hydraulic cement.
> 
> 
> http://www.quikrete.com/productlines/HydraulicWaterStopCementPro.asp


 
I am pretty sure that Hydraulic Cement will only reliably bond to other masonry material (i..e concrete, block, brick, etc.) and will not bond to the ID of a metal pipe.

On the other hand, Spray Foam, will bond to anything and will easily hold back water inside a pipe for a long time. Depending on the pipe size, you can get low expansion foam for smaller pipe, and high expansion foam for larger holes. Also make sure its closed cell type (most is).

Then, I would stuff a rag or newspaper in the conduit to a depth of 12" to keep all of the foam on the end of the conduit. Then I would wipe the inside of the conduit with a clean rag to remove any loose dirt ot dust. Be sure to have something to protect the floor from any over dripping of foam as it will likely stick to any fairly clean surface. Then spray away. Once its cured, you can use a knife or PVC saw to cut it flush with the end of the pipe.


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## mikeh32 (Feb 16, 2009)

one gallon of a, one gallon of b

put in pipe, walk away. 

it will seal it up good


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## BBQ (Nov 16, 2010)

LJSMITH1 said:


> I am pretty sure that Hydraulic Cement will only reliably bond to other masonry material (i..e concrete, block, brick, etc.) and will not bond to the ID of a metal pipe.




It is very effective, read Big Johns post right above yours.



> On the other hand, Spray Foam, will bond to anything and will easily hold back water inside a pipe for a long time.


Yeah it sticks to anything and it will hold back some water for a while and then it won't.

To each their own but if I am looking for a 'permanent' seal it will be concrete not foam.


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## LJSMITH1 (May 4, 2009)

BBQ said:


> It is very effective, read Big Johns post right above yours.
> 
> 
> 
> ...


Sure cement will work if you fill the entire length of conduit... 

If there is a large length and diameter of conduit, and the OP didn't feel like bringing his cement mixer in to work that day, a reliable seal can be accomplished with the spray foam with the methods stated.

Or...we can get really technical and just use one of these on both ends::jester:


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## Big John (May 23, 2010)

LJSMITH1 said:


> Sure cement will work if you fill the entire length of conduit...


 The application I used I figured about 4' of concrete on each end, which for a 2" pipe wasn't a whole lot, less than a 5 gallon bucket.

Granted there was also a 90 at each end so I had no concern about the concrete being pushed down the pipe once it hardened.


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## LJSMITH1 (May 4, 2009)

Big John said:


> The application I used I figured about 4' of concrete on each end, which for a 2" pipe wasn't a whole lot, less than a 5 gallon bucket.
> 
> Granted there was also a 90 at each end so I had no concern about the concrete being pushed down the pipe once it hardened.


 
I was also thinking if the ends were vertical at the surfaces, it would be easy to do this. However, if everything was horizontal, it would be much more difficult unless you rigged up some pouring forms or used some prefab elbows..


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## bmailman20 (Jan 4, 2013)

erics37 said:


> Link Seal?


We just started using these. They work great, but now I need to drill a 4" hole in the foundation for every 2" pipe.


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## Chris1971 (Dec 27, 2010)

I ended up filling the conduit with cement. Worked well.


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## LJSMITH1 (May 4, 2009)

bmailman20 said:


> We just started using these. They work great, but now I need to drill a 4" hole in the foundation for every 2" pipe.


Pretty much the standard in the industry for any type of sealing bushing.

Linkseals are nice, but labor intensive to configure and install.

You could also use something like these (or other brands ), which are much quicker to install on standard conduit sizes as they come ready to use right out of the box.

http://www.bptfittings.com/Catalog/CatalogFamily.aspx?CategoryId=10&FamilyId=744


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## BBQ (Nov 16, 2010)

LJSMITH1 said:


> Sure cement will work if you fill the entire length of conduit...


Say what?

This is not my first rodeo, I have had to go back to number of jobs where foam has failed.



But I guess you are much more experienced at this sitting at your desk.


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## LJSMITH1 (May 4, 2009)

BBQ said:


> Say what?
> 
> This is not my first rodeo, I have had to go back to number of jobs where foam has failed.
> 
> ...


 
Actually, I have done it exactly 3 times on 1.5" and 2" Rigid. Both were horizontal runs through a concerete foundations - one end only. No problems either. 

I am sure you are more experienced and you have done it dozens of times. Never questioned that. :thumbsup:

Oh...and for the record, I do get out to jobsites often.:thumbup:

At home, I also have an awesome set of tools...


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## drumnut08 (Sep 23, 2012)

Chris1971 said:


> We have an underground conduit that goes from a basement to the exterior of a building that we will abandon. We will remove the unused conductors. I'm looking for a sealant that would be good to seal the interior of the pipe to prevent water and moisture penetration. I think poly water makes something but, I can't remember exactly?


Raychem inflatable bladders work well . They work well in active conduits around conductors , so I can only assume they'd work better in an empty conduit . Plumbing expansion test plugs may work for you too in you can find one close to the conduit Inside diameter ?


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## erics37 (May 7, 2009)

BBQ said:


> Say what?
> 
> This is not my first rodeo, I have had to go back to number of jobs where foam has failed.
> 
> ...


STFU. You've never been in a rodeo.


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## BBQ (Nov 16, 2010)

erics37 said:


> STFU. You've never been in a rodeo.


Its an expression son, try to keep up with the grown ups.


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## Jlarson (Jun 28, 2009)

BBQ said:


> It is also cheaper then foam.


Only reason I'd use foam is if I was a raceway I was able to use it again later, couple shots of carb cleaner and you're ready to go. 

Since it's EMT, cement the whole damn thing up and bury it, there's a pretty good chance EMT is mostly gone already :laughing:


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## nolabama (Oct 3, 2007)

After the first of many rodeo clown accidents.


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## BBQ (Nov 16, 2010)

nolabama said:


> View attachment 23063
> 
> 
> After the first of many rodeo clown accidents.


:laughing:

Maybe so but _you_ live in New Orleans. :laughing:


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## nolabama (Oct 3, 2007)




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## BBQ (Nov 16, 2010)

Damn, glad I am not from Ohio. :laughing:


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## balakrishna (Mar 19, 2015)

https://www.youtube.com/watch?v=DPBR5UjFTMA

This is much more durable than Polywater because it has filler in it and sets very hard to block off water. Messy but works and blocks water well.


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## wendon (Sep 27, 2010)

balakrishna said:


> https://www.youtube.com/watch?v=DPBR5UjFTMA
> 
> This is much more durable than Polywater because it has filler in it and sets very hard to block off water. Messy but works and blocks water well.


Are you Rip Van Winkle?


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## Cow (Jan 16, 2008)

wendon said:


> Are you Rip Van Winkle?


I wish he was, that'd be easier to pronounce.:whistling2:


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## wendon (Sep 27, 2010)

Cow said:


> I wish he was, that'd be easier to pronounce.:whistling2:


Is he a brother to Hare? :laughing:


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## balakrishna (Mar 19, 2015)

Hari Bol! This is all I can


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## drsparky (Nov 13, 2008)

Zombie thread!!!!!


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## backstay (Feb 3, 2011)

Chris1971 said:


> We have an underground conduit that goes from a basement to the exterior of a building that we will abandon. We will remove the unused conductors. I'm looking for a sealant that would be good to seal the interior of the pipe to prevent water and moisture penetration. I think poly water makes something but, I can't remember exactly?


Poly water is my choice.

VikingElectric Online Part#: POW FST250KIT

OLD THREAD!! Just saw that!


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