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View Full Version : what potting compound to use for electrical junction box??



wozzzzza
15th January 2024, 10:34 PM
i have a junction box that some one put into concrete when it was laid that is level with the ground and now it is starting to get full of water and tripping breakers all day long. measures around 150mm x 100mm x 80mm, want to pot it with so it can get as wet as it wants without tripping breakers??

droog
16th January 2024, 04:12 PM
For potting compounds I would probably look at one of the flexible ones like polyurethane
RS PRO Grey PUR Potting Compound 500 g | RS (https://au.rs-online.com/web/p/potting-compounds/1991395?)

Past experience with epoxy is that over time cable entry can be a source of moisture ingress
RS PRO Black Epoxy Potting Compound 50 ml | RS (https://au.rs-online.com/web/p/potting-compounds/0851044?)


Of course an electrician would probably use a waterproof junction box and cable glands with some silicone for added protection. Also alows future access to the junction if required.

mic-d
16th January 2024, 06:10 PM
I wouldn't be putting pot plants in a J box.

wozzzzza
17th January 2024, 02:06 PM
For potting compounds I would probably look at one of the flexible ones like polyurethane
RS PRO Grey PUR Potting Compound 500 g | RS (https://au.rs-online.com/web/p/potting-compounds/1991395?)

Past experience with epoxy is that over time cable entry can be a source of moisture ingress
RS PRO Black Epoxy Potting Compound 50 ml | RS (https://au.rs-online.com/web/p/potting-compounds/0851044?)


Of course an electrician would probably use a waterproof junction box and cable glands with some silicone for added protection. Also alows future access to the junction if required.

ok cool, can give a try, the box is that old its lid is fuked and looks like they just drilled a few holes and stuck conduit and siliconed them 30years ago. cant just replace the box as it potted in concrete


I wouldn't be putting pot plants in a J box.
even if they were electric?

wozzzzza
16th February 2024, 10:12 AM
For potting compounds I would probably look at one of the flexible ones like polyurethane
RS PRO Grey PUR Potting Compound 500 g | RS (https://au.rs-online.com/web/p/potting-compounds/1991395?)



whats the texture of this stuff? how liquid is it like how well will it flow around all the connectors and wires?

i noticed yesterday that this circuit does not even have an RCD on it, someone has swapped it out for a normal breaker, now i know why it isnt tripping when it gets wet.

ErrolFlynn
16th February 2024, 10:32 AM
I knew someone who worked at one of those companies that did work related to the various Woomera rocket tests. That was a while ago. Anyway, with circuitry that needed to be reliable and not be shaken apart, they potted it in Araldite. No chance of subsequent repair. No chance of things falling apart on the inside. Expensive. No doubt water resistant.

droog
16th February 2024, 03:43 PM
whats the texture of this stuff? how liquid is it like how well will it flow around all the connectors and wires?

i noticed yesterday that this circuit does not even have an RCD on it, someone has swapped it out for a normal breaker, now i know why it isnt tripping when it gets wet.

Never personally used the product but the datasheet lists it as Low Viscosity and Viscous Liquid.

wozzzzza
16th February 2024, 04:03 PM
Never personally used the product but the datasheet lists it as Low Viscosity and Viscous Liquid.
ok cool, ordered some see how it all goes.

wozzzzza
5th March 2024, 09:48 PM
done it, had a rain free day today and epoxied it.
2 bags of the 500g stuff to fill the box up.

droog
5th March 2024, 10:00 PM
Probably would have been a good idea to replace the rusted bp connectors before potting it.

wozzzzza
6th March 2024, 04:25 PM
Probably would have been a good idea to replace the rusted bp connectors before potting it.
i did, the ones that matter any way, the others there are only to cap off an end of an old cable not used any more thats faulty.