Can I fill and underground rigid pipe with silicone?

[ritelec]

Hello.

There's and underground rigid conduit that comes into someones basement at the panel location (below grade).

Along the line, someone installed an FS box on the other end in the yard which has rotted (disintegrated) and there is water going into the conduit and into the basement.

I will continue the pipe run to where it needs to go with pvc, but sometimes those couplings leak, or it may also be possable that since this pipe is older, it may also have some rot and be leaking somewhere else along the pipe run.

I'm thinking about 90ing when it comes in the building with rigid to get it up above grade level, or dig outside and do the same thing to get it above grade level.
Or, Fill the heck out of the pipe where it comes into the building with silicone.

It may not be too smart.
But I know they want or suggest putting duct seal in conduit to prevent condensation, is there any article that mentions that I can't put a tube of silicone in it?

I may reevaluate the job and run a new piping system but, it won't be easy.

Just wondering about filling it (which I'd rather not, but).

Thank you

 

[petersonra]

I don't think it will hurt anything but whether it will work or not is something else.

Is there someplace you can drain the conduit before it enters the building? Maybe dig a hole around the entry point on the wall, install a drain, and some gravel to keep it open. a small dry well.

 

[GoldDigger]

Standard silicone gives off acetic acid (vinegar) when curing, so you would have to be comfortable that this would not harm the insulation or sheathing of what is in the raceway.
They do make acetone-curing silicone, but that has its drawbacks too.

 

[ptonsparky]

Getting it above grade outside before it eners the building would be the best.

You still have a hole to plug that comes thru the wall where the old came in. There should be something...

 

[Ponchik]

Will silicone dry all the way through when inside a conduit and especially when you have a large amount of it in a small area.

 

[GoldDigger]

Will silicone dry all the way through when inside a conduit and especially when you have a large amount of it in a small area.

It is not actually drying but is undergoing a chemical process catalyzed by the oxygen in the air.
It will eventually harden, but more than a few inches of conduit run may take awhile to cure in the center.
A tube of silicone left uncapped will eventually harden all the way through. (BTDT.)

 

[readydave8]

I have seen silicone solve leak problem but have also seen it work for a year or two and then leak.

As far as duct seal, it may block air and not water? So may prevent condensation but maybe not plug a pipe to prevent water?

 

[ritelec]

Getting it above grade outside before it eners the building would be the best.

totally agree

 

[ritelec]

I have seen silicone solve leak problem but have also seen it work for a year or two and then leak.

yes, that's what I am afraid of.

That and Americans

http://www.youtube.com/watch?v=gPVrFIP0CMs&feature=kp

 

[electrofelon]

Just took a continuing education class and the instructor brought this up. This is an area that could use much more attention by most electricians - including me and I will start being better about it now. Note that if you want to be thorough and comply with 225.27, 230.8, 300.5(G), and 110.3(B), you need to use something that is identified for conductor insulation, bare conductors and for the application. This means you really shouldnt use duct seal, spray foam, or regular caulk. Here is a proper product: http://www.polywater.com/ductseal.html

 

[Fulthrotl]

Hello.

There's and underground rigid conduit that comes into someones basement at the panel location (below grade).

Along the line, someone installed an FS box on the other end in the yard which has rotted (disintegrated) and there is water going into the conduit and into the basement.

I will continue the pipe run to where it needs to go with pvc, but sometimes those couplings leak, or it may also be possable that since this pipe is older, it may also have some rot and be leaking somewhere else along the pipe run.

I'm thinking about 90ing when it comes in the building with rigid to get it up above grade level, or dig outside and do the same thing to get it above grade level.
Or, Fill the heck out of the pipe where it comes into the building with silicone.

It may not be too smart.
But I know they want or suggest putting duct seal in conduit to prevent condensation, is there any article that mentions that I can't put a tube of silicone in it?

I may reevaluate the job and run a new piping system but, it won't be easy.

Just wondering about filling it (which I'd rather not, but).

Thank you

about 4 years ago, i had a similar problem.

iwire had a product he'd used that will seal the conduits with 15' of head pressure,
water standing in the pipe.
it worked wonderfully. it still works. and i can't remember the name of it.:dunce:

it's not cheap, it kicks ass. ask iwire if he remembers it.

if you have to seal a penetration and the leak is coming around the outside of the
pipe where it penetrates the wall, 3M 550. used for sealing boat hulls below the
waterline.

 

[Cow]

You were probably thinking of this, looks like it'll actually do 22 feet of head pressure:

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

 

[ritelec]

Nice. Thank you. I'm starting to feel better about this.


(And Americans)

 

[petersonra]

I don't know if run of the mill caulk or silicone sealant is "identified" for use on conductor insulation, but I get some silicone sealant made especially for the purpose of being on conductors (sometimes called potting material). I have also chatted with the tech support people at several of the manufacturers of the foam products and they have assured me it does no damage to conductor insulation.

As I understand it, the problem with normal silicone sealant is that it is cured with acetic acid (vinegar) and the acid can damage the conductors, not the insulation.

 

[kwired]

I don't know if run of the mill caulk or silicone sealant is "identified" for use on conductor insulation, but I get some silicone sealant made especially for the purpose of being on conductors (sometimes called potting material). I have also chatted with the tech support people at several of the manufacturers of the foam products and they have assured me it does no damage to conductor insulation.

As I understand it, the problem with normal silicone sealant is that it is cured with acetic acid (vinegar) and the acid can damage the conductors, not the insulation.

So what is the problem other then a bare EGC?

 

[petersonra]

So what is the problem other then a bare EGC?

I don't think there is a problem.

 

[Todd C]

PVC conduit dumps water in basement

PVC conduit dumps water in basement

I'm struggling with a similar issue. I understand a below grade 4 inch PVC run will drip a little condensation but this pours into the basement mech room every time it rains through a big gutter/J-box next to the main panel. Its a big service feeder from the Utility Companies transformer. I assume the PVC has been broken or crushed or come apart out there underground somewhere. Digging it up to the transformer pad and doing it over would cost a fortune, disrupt service, and involve the Utility Company. Someone filled it with spray foam and NP1 polyeurethane but it still leaks. Sorry I don't have a solution. A below grade drain just sounds like an other way to let water in at this location but maybe?

 

[Todd C]

NP1

NP1

Pulling out the old caulk and all the spray foam he could reach, getting a clean lip to bond to, and re-doing the seal with a thorough plug of NP1 (Sonoplast) seems to have done the trick. Time will tell.

 

[Jon456]

You were probably thinking of this, looks like it'll actually do 22 feet of head pressure:

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

I used this product to seal a 4" conduit containing three 500 MCM wires and an EGC, then filled the conduit with water to perform a wet megger test. The conduit had a vertical 10' rise, so the seal had to hold a 10' head of water pressure. I can attest to the the water damming performance of the Polywater FST. The key is in the preparation, particularly the proper placement of the foam strips used to separate the individual wires and create a chamber for the foam to expand and encapsulate the wires.

The other good thing about the Polywater FST is that it is removable. I completely removed the plug after the test without any damage to the wires or the conduit. I suspect that will be impossible to do with silicone.

Here's the thread discussing the wet megger test I performed:

http://forums.mikeholt.com/showthread.php?t=163942

 

[kwired]

I used this product to seal a 4" conduit containing three 500 MCM wires and an EGC, then filled the conduit with water to perform a wet megger test. The conduit had a vertical 10' rise, so the seal had to hold a 10' head of water pressure. I can attest to the the water damming performance of the Polywater FST. The key is in the preparation, particularly the proper placement of the foam strips used to separate the individual wires and create a chamber for the foam to expand and encapsulate the wires.

The other good thing about the Polywater FST is that it is removable. I completely removed the plug after the test without any damage to the wires or the conduit. I suspect that will be impossible to do with silicone.

Here's the thread discussing the wet megger test I performed:

http://forums.mikeholt.com/showthread.php?t=163942

I see you are in California, but if you leave that water in the pipe in cold climate areas it will freeze and burst the pipe open.