Canister light warning

[airsix]

Like the Darwin Award, apparently we need a Boyle Award because I had the dumb.

This weekend I assembled my canister light the night before my dives. This was done indoors at an ambient temp of 73F. The canister light and other gear then spent several hours in the trunk of my car in blazing sun and 95F ambient outside air temp. The expansion of the air in the canister was enough to extrude the freshly lubricated o-ring which I unceremoniously dragged down to 80ft without inspecting because I hadn't disturbed it since loading the battery the day before. One switch and one brand new lithium battery pack down the toilet. In this hot weather don't make the same mistake I did.

Ben

[Nwbrewer]

Ouch! That sucks. :angry:

Though I hadn't really thought about it, I'm glad mine is sitting open in the car today.

On another note, I long ago stopped lubing my canister o-rings. It's in pure compression, so it really shouldn't need it. I found it just attracted dust, sand and cat hair. Over 100 dives with no lube on the o-ring and no (non user error) leaks so far.

[Jeremy]

I have about 150 dives on my Dusty Light and have never lubed either of the o-rings once.

[CaptnJack]

No lube

Hope the pack wasn't too expensive.

[fmerkel]

I have about 150 dives on my Dusty Light and have never lubed either of the o-rings once.

Those aren't pure compression O-rings. The ___slide___as you screw them in. Dusty will probably weigh in but I think some lube is a good idea.

How do you get the thing open without lube on them? I definitely NEED the screwdriver and sometimes need to get a strap wrench to hold the body if it's been sitting closed for a few days.

[Jeremy]

I used to use a screwdriver, but recently have just been tightening and untightening by hand.

[fmerkel]

I used to use a screwdriver, but recently have just been tightening and untightening by hand.

My! Strong hands. I have 3 of them and the screwdriver is always needed if they've been closed for > than about 24 hours.

[Jeremy]

Hulk Smash!

[airsix]

The first thing I thought of when I saw the extruded ring was that I wished I'd built it with double o-rings like Jake did.

[Dusty2]

Hey guys, keep in mind that PVC, the material that most people are using, is only rated for 150 to 160 degrees. The interior of you car or worse the trunk can get that hot or hotter in the blazing sun. Easily hot enough to soften the plastic enough to allow it to expand under the pressure it can build up as the air inside heats up. If this happens it an extrude o-rings that are not installed in a grove(captured). Most DIY'ers and allot of the comercial builders don't install o-rings as they are designed to work thus they can extrude under internal pressure.

Best practice is to keep your camera and your canister light in a water filled cooler so it doesn't have to go from a 100+ degrees to 50 in seconds. This will also prevent fogging on your camera.

[Desert Diver]

I used to use a screwdriver, but recently have just been tightening and untightening by hand.

My! Strong hands. I have 3 of them and the screwdriver is always needed if they've been closed for > than about 24 hours.

I've always said mechanics should have 3 hands.

[Joshua Smith]

I'm a little confused. I own 2 can lights- both are Salvo brand, from before they became light monkey. A 10w and a 21w. I love them both dearly, and in fact, I took both of them out this evening w my young cousin who was visiting and wanted to go for a dive.

They both still work great, and the last time I lubed the main O ring in either of them was never. I bought the 10w in 2007 and the 21w in 2008, I think. I'm with Jake, here- as long as they are clean, what benefit do you get from lubing them? Mine close under longitudinal pressure, with no axial torsion. Maybe it prolongs the life of the O ring? There is no friction involved w the closure. Maybe Dusty lights are different?

[fmerkel]

Dusty's light 'cap' has a double O-ring that screws in. Both of them are in a groove and trapped. There is twisting friction as they go into place. It is not a pressure only seal from some tension clips like a lot of light canisters.
http://underthesound.smugmug.com/Underw ... &k=dZSw3Z8

For the pressure only style there is probably no particular benefit from lube other than to attract and hold junk.

[Joshua Smith]

Dusty's light 'cap' has a double O-ring that screws in. Both of them are in a groove and trapped. There is twisting friction as they go into place. It is not a pressure only seal from some tension clips like a lot of light canisters.
http://underthesound.smugmug.com/Underw ... &k=dZSw3Z8

For the pressure only style there is probably no particular benefit from lube other than to attract and hold junk.

Ah. That makes sense. Thanks.