Waterproof housings & cable connections on the DIY by Mad-Monkey



Mad-Monkey
Afternoon all,

Does anyone have any experience of building waterproof housings for electronics? I am making a panel up to be situated outside, which will have a glass/lexan sheet window to show off the boards. There are approximately 2500 1mm cables entering this panel as well as 10 USB cables and 10 power cables. There are 10 PCBs housed in the panel, to be mounted on an aluminium frame which is backlit.

What is an extremely neat, but cheapish method to waterproof something?? If I built the entire box from acrylic and solvent welded the parts together, is this sufficient to weather proof? Any ideas how to make the back removeable but retain the weatherproofing?? With regards to the cables, the USB and Power I can use cable gromets, but the small matter of 2500 1mm cables is proving a nightmare. Would bundling these through 25mm conduit, bunging the end with a clay, and filling with epoxy resin be sufficient. I can make that look nice, but any other ideas?

Many Thanks :mrgreen:

Posted 12 Apr 2011, 15:03 #1 

User avatar
Bernard
Is it to be just weatherproof and not subject to total immersion?

I have prepared enclosures for occasional total immersion but nothing anywhere near to that scale.
I don't like signatures, they take up too much screen space.

Posted 12 Apr 2011, 15:20 #2 


Mad-Monkey
Just weatherproof Bernard. It's only 5v but there is 4amp to each board so didn't want to take any chances.

Posted 12 Apr 2011, 16:00 #3 

User avatar
kandyman
Have you looked through the maplins site ?

http://www.maplin.co.uk/components/encl ... enclosures
Image

Posted 12 Apr 2011, 16:37 #4 


Mad-Monkey
kandyman wrote:Have you looked through the maplins site ?

http://www.maplin.co.uk/components/encl ... enclosures


I had a gander, but I would like a vision panel in the front and they don't go big enough. Although I am now thinking of a series of smaller panels, perhaps 4 PCBs to a panel, but there is nothing pre-made I have seen suitable :(

Posted 13 Apr 2011, 07:00 #5 

User avatar
Bernard
Solvent welded acrylic is certainly weather proof but is easily cracked.
I've constructed fluid tanks in that manner.

If the cables are brought in through waterproof glands vertically through the bottom panel, I would have thought they will be OK. Better still they could be sealed with gutta-percha or similar.That would then stand occasional immersion.
I don't like signatures, they take up too much screen space.

Posted 13 Apr 2011, 09:28 #6 

User avatar
Xpart02
Monk wrote:Afternoon all,

Does anyone have any experience of building waterproof housings for electronics? I am making a panel up to be situated outside, which will have a glass/lexan sheet window to show off the boards. There are approximately 2500 1mm cables entering this panel as well as 10 USB cables and 10 power cables. There are 10 PCBs housed in the panel, to be mounted on an aluminium frame which is backlit.

What is an extremely neat, but cheapish method to waterproof something?? If I built the entire box from acrylic and solvent welded the parts together, is this sufficient to weather proof? Any ideas how to make the back removeable but retain the weatherproofing?? With regards to the cables, the USB and Power I can use cable gromets, but the small matter of 2500 1mm cables is proving a nightmare. Would bundling these through 25mm conduit, bunging the end with a clay, and filling with epoxy resin be sufficient. I can make that look nice, but any other ideas?

Many Thanks :mrgreen:


Hi,
I used to design industrial switchboards years ago,
Sounds like you need an IP55 or 65 rating DB. ( Distribution Board).
The door panel could be cut out to accept a clear panel. Some of ours used to be like that anyway.
Image

Can you find a disused DB and modify it?
something along these lines?
Image

They are all ones I have designed in the past.

Posted 13 Apr 2011, 10:43 #7 

User avatar
Duncan
Very tricky to make them 100% dry. Changes in temperature and air pressure can get stuff past seals.

To allow for breathing, you can get a gland with fabric in it, something like goretex which allows breathing. It means your seals have to work a lot less hard.

Oh, and make sure all the cables enter / exit at the bottom, then gravity is with you, not against you.
Image

Posted 13 Apr 2011, 12:43 #8 


Mad-Monkey
Sure I replied to these! I've got to start making sure I click submit instead of preview! :D

Bernard wrote:Solvent welded acrylic is certainly weather proof but is easily cracked.
I've constructed fluid tanks in that manner.

If the cables are brought in through waterproof glands vertically through the bottom panel, I would have thought they will be OK. Better still they could be sealed with gutta-percha or similar.That would then stand occasional immersion.


If solvent weld cracks easily then I think this would be a bad choice as the panel is going to be a sort of display piece, hence the vision panel and backlighting. I could incorporate a box within a box though that would prevent knocks and bumps, I think this may work out at the cheapest option so far. Cheers Bernard :thumbsup:

Xpart02 wrote:
Monk wrote:Afternoon all,

Does anyone have any experience of building waterproof housings for electronics? I am making a panel up to be situated outside, which will have a glass/lexan sheet window to show off the boards. There are approximately 2500 1mm cables entering this panel as well as 10 USB cables and 10 power cables. There are 10 PCBs housed in the panel, to be mounted on an aluminium frame which is backlit.

What is an extremely neat, but cheapish method to waterproof something?? If I built the entire box from acrylic and solvent welded the parts together, is this sufficient to weather proof? Any ideas how to make the back removeable but retain the weatherproofing?? With regards to the cables, the USB and Power I can use cable gromets, but the small matter of 2500 1mm cables is proving a nightmare. Would bundling these through 25mm conduit, bunging the end with a clay, and filling with epoxy resin be sufficient. I can make that look nice, but any other ideas?

Many Thanks :mrgreen:


Hi,
I used to design industrial switchboards years ago,
Sounds like you need an IP55 or 65 rating DB. ( Distribution Board).
The door panel could be cut out to accept a clear panel. Some of ours used to be like that anyway.
Image

Can you find a disused DB and modify it?
something along these lines?
Image

They are all ones I have designed in the past.


Feasible if I could find one I guess, are they easy to find 2nd hand? Will have to scour ebay later! Cheers! :)

Duncan wrote:Very tricky to make them 100% dry. Changes in temperature and air pressure can get stuff past seals.

To allow for breathing, you can get a gland with fabric in it, something like goretex which allows breathing. It means your seals have to work a lot less hard.

Oh, and make sure all the cables enter / exit at the bottom, then gravity is with you, not against you.


Cheers Duncan, are the glands called anything specific to search for, or just a case of doing a bit of simple mans explanation search!? :roll: :)

Posted 14 Apr 2011, 08:14 #9 


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