water filter housing as a dive light canister?

BlueD

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Mar 28, 2012
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Hi everyone! Avid diver here experimenting with backup canister lights for fun. Thanks for an informative and thought provoking forum!

Tried to search the forum but found no posts, perhaps someone could direct me if this has been discussed in the past.

Has anyone thought about using standard water filter housings as canisters for dive lights?
They are rated 10 bar, the ones with clear plastic seem to be rated 1-50 celcius and it says "protect from frost", so probably the plastic becomes brittle with cold, but maybe the ones that are not clear? Seal the holes with jbweld or other plastic or marine epoxy, and put a glands on it? what do you think?

The white one, fourth from left on the top with the screw down nuts looks interesting.... and they are under $60, with most under $30.


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Codiak

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I'd not read too much into the 10bar rating as I'd assume that's internal pressure vs external.

Even so, it's not a bad idea. I'd machine or mold a whole new cap but otherwise I'd expect the canister to hold up fairly well.
Easy enough to take one down on a dive to test it out.
 

BlueD

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I'd not read too much into the 10bar rating as I'd assume that's internal pressure vs external.

Even so, it's not a bad idea. I'd machine or mold a whole new cap but otherwise I'd expect the canister to hold up fairly well.
Easy enough to take one down on a dive to test it out.
Thanks for your reply Codiak. If I had access to a machine shop or molding device, I would not be thinking about those housings.
It looks like another forum member is using a water filter housing as an improvised pressure pot, so it seems they are at least somewhat pressure-rated to above five bar. Would you mind explanining the difference between internal and external pressure? is it that that the seal locks are locked by pressure from inside and might not work when pressure is applied from the outside?
 

DIWdiver

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Three things:
1. The seal is designed to hold pressure in. It may or may not hold pressure out, because the seal could get pushed out of position if it's not contained against outside pressure.

2. External pressure reverses the direction of stress in the material. It's mostly or possibly all in tension when the pressure is inside. It's mostly or all in compression when the pressure is outside. Most materials are as strong or stronger in compression than in tension, so you should be good to at least 10 bar.

3. External pressure will press the lid tightly onto the housing, so the latches are unnecessary past 10 or 20 feet, and are under less stress during a dive than at the surface.

uh... four things...
4. If you are going anywhere near that deep, you should be using proven gear, not experimenting.

uh... five things...
5. I know you're not planning on taking this thing that deep. It won't implode on you unless you compromise it somehow. But depending on how the seal is designed, it may or may not hold.
 

SmokedCPU

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Jan 9, 2010
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just give it a try
It may be less tought than delrin canister but may be an alternative.

for depth rating, send it to sombody who have a pressure pot to test it, or dive it with a weight in, to desired depth, and then let it go in the abyss with a reel to 50-100ft more. There it may implode or flood.

Remember to have fun while experementing.
 
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