What depth to test a new housing?

[peterbkk]

Yesterday I received my new Light & Motion Mako housing for my Sony PC330. From my online research, I already knew that I was buying a nice piece of equipment but I was suitably impressed when I opened the package and laid hands on the housing for the first time. This thing gives you a lot of confidence - very well engineered. The design is logical and the button placement good. I look forward to getting it underwater on a wreck dive next weekend.

In the manual, L&M recommend that, before taking the video camera underwater, I should do an underwater test without the camera inside, just to make sure none of the seals were damaged during shipping. This seems to me to be overly cautious but I'll follow the advice.

Here is my question: how deep do you need to take it to be sure that the seals are working?

Here is what I am thinking. In the first couple of meters, there is some differential pressure on the o'rings - enough to force water past any flaws in the seal. After 2 or 3 meters, the differential pressure builds up to the point where the o'rings are forced tightly against the surfaces, flattening into a "D" shape. So, if it is going to leak, it is most likely going to leak in the first 2 meters.

If the above is true, then I have two choices:

1. On the weekend, take down the empty housing on my first dive, check it out for leaks between dives and, if all OK, put the camera into the housing for the second dive.

2. Take the empty housing down to the bottom of a local swimming pool (about 2 meters deep). If no leaks, take the camera underwater on all the weekend dives.

The downside of option 1 is that I have to open the housing and play with the camera on a wet dive boat in the middle of a potentially choppy sea. Also, I worry about Murphy's law. If Murphy sees me diving with an empty housing, he is almost certain to send over a pod of playful dolphins to anguish me.

The upside of option 2 is that I get to do all the weekend's dives with a working camera. Also, I can load the camera into the housing in the comfort (and dry air) of my house and leave it in the housing all day long, reducing the risks associated with an open housing and exposed camera on a dive boat.

Of course, option 2 is only valid if it is a reasonable test of the housing's leakproofness. A marginal or inadequate test is also going to tempt Murphy.

What do you all think? Is a 2-meter-deep swimming pool test adequate?

Regards
Peter

 

[diversteve]

FWIW, this is what I do. I check my housing prior to the start of each trip in a pool. Preferably on location, although last summer it was in my parents pool here. The only time I detected a leak, it was at 9', I tied it off to the skimmer pole and left it there for about 15 mins.

My manual also recommends taking the housing to depth the first dive and then installing the camera. However, I've done first boat dives several times with the camera in the housing with no problem, having set it up in our clean/dry condo prior to diving. It's a lot easier to ensure there's no sand/hair etc. on the seals that way also.

Course there's always that Murphy fellow, what's more important, missing a few dolphins or ruining your PC330?

YMMV

 

[MonkSeal]

This seems to me to be overly cautious but I'll follow the advice.

It's not overly cautious. It's the proper way. New housing has to be tested after shipment as well as after any service.

Here is my question: how deep do you need to take it to be sure that the seals are working?

Go for option 1. Better safe then sorry. Put silca gel pack in empty housing to check if any moisture is present during dive and go for a first dive without camera. After dive rinse it with fresh water, dry, open, put camera and go for a second dive.

Checking housing before every trip is little bit overly cautious if housing is used regularly. If you make long breaks (two-three months) then you should perform a test before putting camera inside.

Regarding Murphy, he'll catch you if you go for option 2 and flood your camera.

 

[peterbkk]

Go for option 1. Better safe then sorry. Put silca gel pack in empty housing to check if any moisture is present during dive and go for a first dive without camera. After dive rinse it with fresh water, dry, open, put camera and go for a second dive.

MonkSeal,

But how deep do you need to take the housing before you can be sure the seals are good. 3 meters? 10 meters? 40 meters?.

Regards
Peter

 

[MonkSeal]

MonkSeal,

But how deep do you need to take the housing before you can be sure the seals are good. 3 meters? 10 meters? 40 meters?.

Regards
Peter

I would go for max depth declared for the housing +5 meters. If it's deeper than you plan to go then go for max planned depth. I took my housing (Oly PT-015, rated 40m) to 45 meters at first dive.

Carefully look for any bubbles comming from the housing and try to estimate if any of them is caused by housing leaking. Shake the housing to release any air stucked on hosing surface, buttons, etc. Listen to any cracking sounds and try to remember it for the future reference as normal behaviour.

 

[Kim]

Actually your logic is correct. A camera housing is MUCH more likely to flood in just a couple of meters where the pressure differential is less and the O rings are therefore under less pressure.
That said - if you take a case to depth then you cover both - shallow, and deep - so I suppose if you want to be really sure you are better off doing that, although as you pointed out you need to be VERY careful opening and closing housings on a boat. (something I really try to minimize as much as possible). It's hard to keep ambient moisture out when you are opening it on the boat and you need a lot of silica to take up the condensation - something which I have occasionally had problems with no matter what.

Personally, when I got my PT-015 I just stuck it in the bath and left it submerged for a couple of hours!! :11: (if you do that though I take no responsibility! ) If I was you I'd probably be happy enough with the pool test - but I'm not, so it's up to you!

 

[miketsp]

I'm a pessimist and so I'd go for option 1, but I must admit that with everybody I know that has had water ingress problems, they have been obvious by the time they reached 2m.
As you say, beyond this the main surfaces are squeezing the main o-rings tighter.
Once you get really deep then the weak point becomes the control-button o-rings.

 

[Kim]

I would go for max depth declared for the housing +5 meters. If it's deeper than you plan to go then go for max planned depth. I took my housing (Oly PT-015, rated 40m) to 45 meters at first dive.

Of course anyone doing this would need to be comfortable going to that depth (and trained!)

 

[Kim]

Once you get really deep then the weak point becomes the control-button o-rings.

That is also my understanding - especially on the PT-015. That's not your housing though so it wouldn't apply.
For weak link controls like the PT-015 it's the ones that are designed to move a little so you can get the camera in. The one on the PT is the jog dial which is set with a spring and has to be raised a little to put the camera in, and then dropped back onto the top of the dial. With those type of controls correct alignment is everything!

 

[Rick Murchison]

As a practical matter, with a new housing I put enough weight inside to sink it, throw it in the pool (10'/3m) and leave it overnight. If it doesn't leak, I use it.
So far that's always worked...
Rick