underwater challenge

[mr.dani]

Hi all ;
This is me again, but this time with a new challenge of a friend of mine , this time I had to send a camera down to a depth of 100 meter under water and send the video signal through a wire  up to a small screen on my boat ,
At first I thought this is an easy one ,but when I tried it on real , I had the same problem every time.
   The water entered the upper cover of the glass container at the point where the signal wire is coming out from the glass container . I tried many types of glue to seal that  point with no success at all and wasted a cheap camera each time .
So ; would you please help me with this challenge . I would like to know if there is any kind of ready made camera case that will solve this problem . a small case will do the job because there is no servo motor to guide the camera or any other kind of rc .
I just want to guarantee that no water will reach the camera through the point of signal wire     

[xxpitt]

Flite Test | Waterproofing Electronics: http://youtu.be/s4z8QMgTEA4 might be worth giving this a watch as a fail safe when your case leaks. Also they use an epoxy to plug holes maybe you should try that around wire that comes out of case to plug the hole

[Tecnic]

Try using a diving bell method
i.e. a container with no bottom, the camera up inside the trapped air, using weights to keep the container up the right way and to counter boyancy

[xxpitt]

Like water world like it

[bigMouse]

I like the idea of a metal or acrylic cylinder with an O ring seal typ lid.

epoxy and O rings around the cable. Epoxy needs to penetrate the wire insulation otherwise water will creep through! Your talking about appx 50 psi pushing water up the insulation!

[xxpitt]

Yep think the slower setting epoxy the better

[mr.dani]

thanks all I'll try epoxy

[Tecnic]

I like the idea of a metal or acrylic cylinder with an O ring seal typ lid.

epoxy and O rings around the cable. Epoxy needs to penetrate the wire insulation otherwise water will creep through! Your talking about appx 50 psi pushing water up the insulation!

Dive bell is best
At those pressures the soft cable will compress and become smaller in diameter no matter what type of seal is used

[xxpitt]

http://www.securitycamera2000.com/products/Underwater-Waterproof-Camera-for-Fishing-with-IP68-AV-Cable.html

[Cobs]

Or look at the Neptune SB1

[bigMouse]

Wow hang on! I misread the question as 100ft but it's 100m so pressure would be appx 150 psi, also 300 ft is a long way to transmit a video signal through a wire. Not exactly simple!

[xxpitt]

How about this http://www.securitycamera2000.com/products/540TVL-SONY-CCD-Submarine-Underwater-50m-Color-Mini-Fishing-Camera.html

[BIRDS-EYE-VIEW.NL]

ok in the past I build underwater camera's and video lights and this was always an issue. But there are a few solutions to solve the problem.

first one is simple. buy underwater connectors in your local dive store. Keep in mind that these things can be very expensive.

second one is also simple. Make a valve in your housing and pre pressurize the enclosure with gas/ compressed air. They do the same with the better underwater watches for professional divers.

on ROV's we filled the whole enclosure with an special non conductive oil. This way your housings can't be crushed by the pressure eighter.

Last recommendation from my side is use the right cable! lots of cable shields are foamed with micro pockets of air. so they aren't tight under pressure. We had some explosions in the past because gas from the batterypack goes though the cable to the hot lamp and it ignited there.

Nothing to do with making things waterproof but long cables wont work well with unbalanced video signals. try to balance your cable and use a driver a a signal transformer. This way you can run the signal through longer cables.

good luck