circuit board waterproofing

[dh465]

I feel like this belongs in the motherboard section, but if im wrong please move this to the appropriate place. 

I have a "water resistant" poe ethernet extender for a wifi access point in my yard. 

the electronics in it work great! 

the housing is the stupidest thing I ever seen. 

it has rubber rings that wrap around the ethernet cables and then it screws a female bushing into the case to create a "water tight" connection. the design does not allow for a standard ethernet cable to be plugged into it, i had to cut off the excess plastic sheathing near the end of the ethernet cable... the weird looking serrated part of the ethernet cable to make it fit in the rubber enough to screw down. the first time it rained, water penetranted into the housing and destroyed the board. I bought another, tightened it more, rained again, fried again....

I now have a 3rd! one on the way. I plan on filling the entire internal housing, circuit board and all with vasoline, "sealing" the unit, then essentially dipping the entire exterior in hot glue. 

im tired of digging this up. obviously this isnt an elegant solution but idc its underground. 

any reason that this wont work or shouldn't be done? 

[mariushm]

They make lots of waterproof ethernet connectors from cheap 3-5$ ones to super expensive ones : https://www.digikey.com/short/q5rdb5d7

 

Up to you  how much you want to go.

 

You can get waterproof /  watertight project boxes (look in datasheets for the difference) : https://www.digikey.com/short/dp0dbctb

 

Could get a steel / aluminum one, drill holes to install your waterproof connectors from link above, then use small patch cables to connect the connectors to the actual poe extender board/case)

 

Basically have sealed box sealed in a second box.

 

 

[jaslion]

2 minutes ago, mariushm said:

Basically have sealed box sealed in a second box.

And worst case fill it with silicone it's how a lot of electrical outdoor coupling basically operate. Perma seal stuff in epoxy and silicone.

[Godlygamer23]

Conformal coating could also be an option.

[Beerzerker]

Dielectric grease would be a better choice than vasoline since vaso can become "Goopy" when exposed to moisture/water.
Evidence of that is when guys use it for sub-zero XOC stuff and they use vaso - It gets goopy during this useage and that's just from a few hours of using it this way.

While it does repel water in general (Made from petrolium), the fact it can become goopy says it's not the best thing for this kind of use but dielectric grease IS formulated for damp/wet conditions because that's what it's used for concerning electronics.

You can coat/slather the entire thing with a thin coating of dielectric and that should do it as long as it's not directly exposed to moving water, meaning it should be in an encasement to help with that.
As long as you've gotten it completely coated that should do the trick.

Moving water will tend to rinse the coating off over time whether it's a coating of vaso or dielectric so you'd want to protect it from that effect.
You've already stated it will be inside of a box so it should be fine that way.

[Echothedolpin]

Water resistant isn’t the same as watertight or waterproof. Are you burying this?

 

Easiest solution is to sink a weatherproof utility hookup box in a location that doesn’t get submerged in water.

 

edit: just a note: filling a poe extender with an insulating material will likely severely reduce the service life of the electronics. I couldn’t guess by how much, but it would probably be significant.