Making a leak free pvc storage canister to attach to my back plate

[UnderSeaBumbleBee]

I want to make an inexpensive storage canister to attach the the butt of my backplate similar to the OMS canister.

My plan is to cut a length of 2 inch pvc pipe. Generously glue a cap on one end to seal it.

It is the other end that has me. I have thought of gluing a male threaded adapter on the other end and using a female cap. I would put an o ring around the male adapter and perhaps an o ring up inside of the female cap. I would cut down the male adapter so that it would screw into the female cap enough to put pressure on the o ring.

What has me concerned is that in the event I need to get into it will be too hard to unscrew. I have to use a strap wrench to unscrew my Nemo light. I am chick and my hands just aren't that strong.


I don't plan to get in and out of it that often as it will have a strobe, some chem sticks and few other things.

What do you guys suggest?

 

[350xfire]

I want to make an inexpensive storage canister to attach the the butt of my backplate similar to the OMS canister.

My plan is to cut a length of 2 inch pvc pipe. Generously glue a cap on one end to seal it.

It is the other end that has me. I have thought of gluing a male threaded adapter on the other end and using a female cap. I would put an o ring around the male adapter and perhaps an o ring up inside of the female cap. I would cut down the male adapter so that it would screw into the female cap enough to put pressure on the o ring.

What has me concerned is that in the event I need to get into it will be too hard to unscrew. I have to use a strap wrench to unscrew my Nemo light. I am chick and my hands just aren't that strong.


I don't plan to get in and out of it that often as it will have a strobe, some chem sticks and few other things.

What do you guys suggest?

PVC threads are really difficult to unscrew, even out of water. Consider using latches.. However that will add an expense and more difficulty to the build! I am not sure how the OMS canister would do under pressure either. Probably difficult to undo as well. Try posting a WTB ad on the lighting classifieds for a light canister with latches and just tell them you want CHEAP!!! Plug the holes with the appropriate fittings and done!

I don't know that you'll find a canister for less than $20-30 but you could always play the "poor weak chick" card and hope someone bites!! hahaha

 

[UnderSeaBumbleBee]

Yeah, the difficulty of getting it open was has me stumped. I want a bit more storage than the can light batter compartments that I have seen. I already have extra pipe left over from a house I have been remodeling so I just need the other end.

I have also thought about getting a reducer or coupling and cutting some pipe and putting the o ring round that, but not sure what type of latch to use to put enough pressure on the o ring.

 

[mike_s]

My plan is to cut a length of 2 inch pvc pipe. Generously glue a cap on one end to seal it.


[snip]

it will have a strobe, some chem sticks and few other things.

I look forward to following this to see what your overall solution is and how the outcome is on not leaking.



so if you get a 2" PVC pipe, and add a threaded adapter to the end, it might up having an opening slightly narrower than 2".

are there strobes that are less than 2"? I'm thinking maybe my Princetontec strobe might be. (from the one I've got).



Also, most strobes and chem sticks should be able to withstand getting wet under pressure. but not sure what your other items are.



as an alternate solution, I know you mentioned the OMS canister.

You can get it for $46 from Scubatoys and then get 10% discount. or $39 from Leisure Pro.


and you don't have to risk your other things (keys, etc) getting wet on a "trial basis".

 

[dumpsterDiver]

I have an old Underwater Kinetics light, that has a large screw on bezel. I will sell for pretty cheap. This will work, the pvc pipe may not.

 

[Cave Diver]

Yeah, the difficulty of getting it open was has me stumped. I want a bit more storage than the can light batter compartments that I have seen. I already have extra pipe left over from a house I have been remodeling so I just need the other end.

I have also thought about getting a reducer or coupling and cutting some pipe and putting the o ring round that, but not sure what type of latch to use to put enough pressure on the o ring.

You might try looking for a PVC union like this one:

It's 3 pieces. One end has a collar for the nut and a flat face, the other end has a grooved face with an o-ring and is threaded and the third piece is the nut itself. When you tighten the nut, the face of the collared piece seals against the o-ring on the threaded piece.

You'll have to cap one end and attach the other to your pipe. I know that sizes up to 2" is available at Lowes. Not sure if they keep anything larger in stock though.

I agree with the others that either using a latch, or getting a used light canister with a solid lid would be a better option.

 

[elmer fudd]

I'd be inclined not to make it waterproof, just glue one end and slip the other on using some silicone grease for lube. Then I'd drill a few holes in it for ventilation. If you seal it up, then you'll end up fighting the vacuum effect in the tube created by the outside water pressure when you try to open it. If things need to be kept dry, then consider putting them in ziplock bags, balloons or condoms before putting them in the canister.

 

[johnsub]

I don't have any experience in this but i recently read a post somewhere about pvc made underwater housings for camcorders.
They used threaded end caps at both sides, one side glued tight.
Maybe its possible to do the same with a smaller pvc tube?

Here are some video links:

YouTube - d.i.y underwater housing for video camera part1
Underwater Camera Housing - Video

Just thought it might help. Hope its not a stupid answer to your question.

 

[UnderSeaBumbleBee]

Thanks for the suggestions everyone.

I appreciate the offer of the UK light housing, but I have some specific stuff I want to take along and need bit more room. And I kind of want to see if I can make one. A girl has to have some fun ya know!

That fitting you posted Cave looks interesting. Going to check it out.

John the video clips above provided some useful thoughts. I appreciate you pointing me to them. His part two used a version of something I have been thinking about today.
YouTube - cyonics's Channel

I was thinking of machining two groves into the pipe itself like he did for the lid. And then putting o rings in those groves. I might have to machine out the cap slightly. I also might have to consider using pipe heavier than schedule 40. I am going to make the prototype out of 40 since I already have it on hand. I need to find a good O ring source.

Also to help overcome the vacuum pressure created, I am considering putting and eye bolt on the end to give myself a handle. I am thinking of putting an eye bolt at the other end and then running a bungee with hooks from one end to the other to create some pressure for a cheap latch.

Bungee works well in other scuba apps. I was going to buy another set of steel springs for my larger pair of jet fins, but I saw the post on using bungee to make straps instead and it works well. My nephew uses my fins once in a while and so when he needs them we just cut off my size bungee and tie on the size to fit him burn the ends and off he goes. I can fit my foot, with my shoe on inside of his shoe, so definitely need different size heal straps.

For testing, I am going to fill it with some small rocks and paper towels, then let it soak in the spare bathroom tub for a couple of days. If that works, then a friends pools for a few days in the deep end. Then take it on a dive with the paper towels and rocks a few times.

 

[spectrum]

Genova the big PVC supplier has a series of fittings that includes 2 lugs on the bell mouths. Plugs with rubber seals push in and are locked onto those lugs with a twist. This makes for the easy addition of clean outs and pressure testing. Find a Genova PVC dealer.

See here:
http://www.genovaproducts.com/docs/PlumbingCatalog_w_links.pdf#page= 11
See the twist lock plug on page 57 of the PDF.

Pete