Butyl rubber breaking down? Light niche leak help

[Jerryrigged]

Hey TFP Crew,
Last summer I had to replace the light fixture as the wiring had worn through and started tripping the GFCI. So I pulled through a new fixture & wire, which was super fun (\s) I'd rather not repeat that if I don't have to, but it's done. The previous fixture was sealed in the conduit with epoxy which also was a pain to chip away enough for the new wiring but I got it.

I read a few places that butyl rubber was good for sealing the conduit instead of epoxy for easier future removal if needed, which makes complete sense, so I tried as best as I could as the pool was still full. It worked for a little while then started leaking. I tried a 2nd time to add more (more is better right ) and it didn't work either.

Got the water down below the light, and today I pulled the light and found large chunks of the rubber just sitting on the bottom of the niche. I assume these were the 2nd attempt and it didn't stick. The rubber has gotten softer and has turned somewhat gooey and sticks to everything except the old epoxy apparently. Way more sticky/stringy than it is when it's new. It's like it's breaking down in the water. It's gone kind of grey and the texture just isn't close to when it's new.

This is what I've pulled out so far. I also put some 'new' stuff on the right side so you can see the difference in color. You'll just have to trust me that it's gooey and took a lot of scrubbing to get off my hands. New stuff sticks to itself, not me.

Here's what I'm looking at right now. Wires are still coated in gooey butyl rubber and there's still epoxy from the last guy cursed with this task as well.


Any ideas what's going on? Is this normal or did I do something wrong? Should I just try again now that it's dry and use more butyl or do I try to clean it off and go with epoxy and hope it's good?

Thanks for your help,

 

[Bperry]

Hey TFP Crew,
Last summer I had to replace the light fixture as the wiring had worn through and started tripping the GFCI. So I pulled through a new fixture & wire, which was super fun (\s) I'd rather not repeat that if I don't have to, but it's done. The previous fixture was sealed in the conduit with epoxy which also was a pain to chip away enough for the new wiring but I got it.

I read a few places that butyl rubber was good for sealing the conduit instead of epoxy for easier future removal if needed, which makes complete sense, so I tried as best as I could as the pool was still full. It worked for a little while then started leaking. I tried a 2nd time to add more (more is better right ) and it didn't work either.

Got the water down below the light, and today I pulled the light and found large chunks of the rubber just sitting on the bottom of the niche. I assume these were the 2nd attempt and it didn't stick. The rubber has gotten softer and has turned somewhat gooey and sticks to everything except the old epoxy apparently. Way more sticky/stringy than it is when it's new. It's like it's breaking down in the water. It's gone kind of grey and the texture just isn't close to when it's new.

This is what I've pulled out so far. I also put some 'new' stuff on the right side so you can see the difference in color. You'll just have to trust me that it's gooey and took a lot of scrubbing to get off my hands. New stuff sticks to itself, not me.
View attachment 628436
Here's what I'm looking at right now. Wires are still coated in gooey butyl rubber and there's still epoxy from the last guy cursed with this task as well.
View attachment 628437

Any ideas what's going on? Is this normal or did I do something wrong? Should I just try again now that it's dry and use more butyl or do I try to clean it off and go with epoxy and hope it's good?

Thanks for your help,

Any reason you’re not using a polyurethane caulk/sealant? I wouldn’t use the rubber stuff, it obviously failed.

 

[Jerryrigged]

Hmm, no reason other than I didn't see it recomended. I found people saying epoxy putty or butyl rubber, but had seen some people say don't go with caulking. Any recommendations on a specific product?
Thanks again,

 

[PoolStored]

If there isn't a leak in your conduit then why worry about doing anything to seal it. There really isn't any reason to do it.

You normally allow water to flow into the conduit. The conduit should be water tight up to a junction box well above the water line.

 

[Bperry]

If there isn't a leak in your conduit then why worry about doing anything to seal it. There really isn't any reason to do it.

You normally allow water to flow into the conduit. The conduit should be water tight up to a junction box well above the water line.

This is true.

 

[Jerryrigged]

The conduit does leak a significant amount if not sealed in my case. Leak only started when I replaced the fixture and I verified with dye.
It would be a huge project to fix the conduit due to the concrete deck.

 

[InyoRich]

There are rubber stoppers available to help you out (google "Pool light cord stopper"). I've never used them, but the stopper would occupy most of the space in the conduit and (theoretically) might only require a light coating/application of a good marine-style sealant to stop the leak in the light conduit.

 

[Bperry]

The conduit does leak a significant amount if not sealed in my case. Leak only started when I replaced the fixture and I verified with dye.
It would be a huge project to fix the conduit due to the concrete deck.

You’re kinda stuck needing some sealant in that case. Something 100% waterproof. I’ve not had great luck with the epoxy stuff staying together under water but other people have. I think I’d go for the 100% silicone sealant but it’s gotta be dry before applying.

 

[Bill1974]

The normal go to in this case is epoxy putty. Surface prep is also important to make sure good bonding/sealing being everything.

I had gone through this on my niche leaking a number of times. I replaced the niche which I had the conduit fitting cut off and replaced with a conduit coupling (threaded on sides). The conduit coupling is more substantial. Welding on the conduit coupling seems to have solved the issue of the brazed on nut from falling off and causing the leak. I was getting the liner replaced and the patio around the pool replaced so it was the time to fix it. Doesn't really help you but seems to be a more permanent fix.