Reef Safe Waterproofing of Electrical Connections?

[NeveSSL]

Hi everyone,

Been thinking about this and thought I'd ask. I am going to be putting a float switch at the bottom of a 50g vertical tank. The leads of the float switch will almost certainly not be long enough to reach the bottom of the tank, so I'm planning on extending them and waterproofing them. My first thought is to solder them, heat shrink them, place a 2" drinking straw around the joint, and fill it with reef safe silicone. Let it cure for a week or so and then use it. I think that should work and should be fairly simple, but have any of you done something different that may work better?

Brandon

 

[Brad Miller]

There are float switches made so you may not have to do that, like these...
https://www.amazon.com/Magnetic-Float-Switch-Bracket-Only/dp/B01HE4K5SQ

 

[NeveSSL]

I'm not sure what you mean. I am already using a magnetic mount and a float switch just like that one. The problem is having the wire come back up through a tall tank through the water.

Brandon

 

[Brad Miller]

Got it now...
Your idea is prob what I would do too.
Just using the heat shrink with epoxy already in it would be fine though.

 

[NeveSSL]

I had thought about that, but was concerned whatever is used inside of them would not be reef safe.

Brandon

 

[Brad Miller]

I believe most all epoxy is considered reef safe

 

[NeveSSL]

Right, but I'm not 100% sure they have epoxy in them. In fact, I wouldn't think they do because epoxy is two parts.

Brandon

 

[BigHildy53]

Use a through the wall float switch: https://www.mcmaster.com/49175k38

Another option is a vertical float switch with an electrical cord and piggy back: https://www.mcmaster.com/liquid-level-pump-float-switches. I use one to turn off the RO/DI unit when my storage tank is full.

 

[Brad Miller]

The heat shrink with epoxy already in it can be found for underwater applications...I've used them hundreds of time over the years for all kinds of things.
When you heat them slowly, the epoxy will push out the ends and be very clearly visible, in a small blob around the wire.
Years ago (when my beard was black) I used these on the splices to 400' deep submersible well pumps.

The other suggestion on a plastic vertical float is a good idea also, depending on the water flow and placement, it will need to have a firm vertical rod to keep the float vertically steady.

 

[Awesome Dennis]

The rubber heat shrink tube and the "goo" inside that oozes when you heat it are not reef safe and I wouldn't let them touch any water after filtration.

 

[NeveSSL]

Thanks, guys!

There will be a fair amount of pressure at the bottom of this tank, so anything through the wall doesn't make me comfortable.

Thanks, Brad. I full believe them to be water proof, but my concern is the reef safe aspect of it, as Dennis mentioned. I've recently read that liquid electrical tape should work well and also be reef safe after curing as it is basically just vinyl and fully inert in the water. May do that route.

Brandon

 

[Brew12]

This is my "go to" when it comes to waterproof electrical connections.
https://www.amazon.com/Dow-Corning-Vacuum-Lubricant-5-3oz/dp/B001UHMNW0

I would solder the connection, apply a thin layer of this over the wire, and do a short and then a longer section of heat shrink.

 

[NeveSSL]

Interesting. Have you used it in your tank before?

Brandon

 

[Brew12]

Interesting. Have you used it in your tank before?

Brandon

I have, and it is reef safe. I like it because it doesn't "cure" which improves its ability to keep water out. I use it on pin connectors to keep any corrosion out (it is non-conductive) and since it doesn't cure it acts like a lubricant allowing me to disconnect and reconnect it at any time.

 

[Brad Miller]

Brew,
I've used that many times on electric lugs and electronic pins, that's just to keep moisture off the terminal, pin or lugs so corrosion doesn't happen, not to put around a wired connection under water with regular heat shrink, without the epoxy watertight seal.
You would have to still use an epoxy heat shrink not just a regular heat shrink, wouldn't you ?

 

[Brew12]

Brew,
I've used that many times on electric lugs and electronic pins, that's just to keep moisture off the terminal, pin or lugs, not to put around a wired connection under water.
You would have to still use an epoxy heat shrink not just a regular heat shrink, wouldn't you ?

That was why I started using it. After having a few butt splices fail in trenches that fill with water I started having my electricians apply this around every splice connection prior to sealing it. Haven't had a failure since.

 

[Larry L]

There will be a fair amount of pressure at the bottom of this tank, so anything through the wall doesn't make me comfortable.

FWIW, people use through-the-wall fittings all the time on tanks much larger and deeper than 50 gallons, look around at any of many pictures of water mixing stations.

 

[n2585722]

I used 1/4" schedule 80 PVC and threaded the end with the float switch. Then screwed in the float switch with a o-ring to seal it. Below is a photo of the full float switch. My longest one is about 4 feet. This was made for some amout of adjustment with a 1/2" probe holder I got from Avast Marine.

 

[Brad Miller]

Very Cool Danny, that looks like ive bought before

 

[foxt]

I used the same approach that n2585722 used - house the switch and the wire using pvc, and seal that to keep water out. It has the extra benefit of giving you a way to suspend the switch in the tank from the top, mounting the switch at the end of the pvc, and using a bulkhead fitting on the other end to then hang the pvc from the top surface of the tank. Been set up that way for two years in my RO tank, no issues so far ...