Leaking housing

[BlueDevil]

I have had a Canon A640 camera for over a year and use the Canon WP DC8 housing for it. Recently while on a 3m dive I noticed water in the housing and surfaced straight away. By holding the camera out of the water on an angle so the water didn't touch the camera I was able to save the camera. Probably had about 2 teaspoons of water inside - definitely not condensation. I checked the housing O ring thoroughly and could find no fault. I took the housing without the camera on a couple of dives and it was okay.

So it performed okay for the next few dives and then a few days ago, again on a shallow 3m dive, I found water in the housing after the dive. This time it was only 2 large drops, but no fogging of any sort, so again not condensation.

Anyone else had any problems with Canon housings?
Any suggestions as to the cause?
I am considering my options - should I just take it to Canon and get it tested and serviced? Or, having lost faith in this particular housing should I go and buy a replacement housing?
I am going on a trip to Indonesia soon and don't want to take any chances on flooding the camera!

 

[wjsdive]

If it has been a year and you are sure you are very careful with O-ring maintenance it may be time to get new o-rings. If you have time I would suggest having it thoroughly serviced at Canon or a reputable sevice center. Every button and knob is a potential leak and unless you are very confident I would leave the replacement of those o-rings to qualified service folks. You don't want to miss those shots on your Indonesia trip. If the housing worked for a year it is probably not the fault of the housing itself.
Good luck on your trip and remember: Its all about the o-rings and maintenance.

 

[herman]

If you get it serviced, test dive it before trusting your camera to it. Service shops do make mistakes. I don't trust any gear recently serviced until it has been on at least one dive. It's much better to find out at home (and with no camera) than 1000 miles away at 100ft.

 

[RTRski]

You might be able to pinpoint the failure point a bit more. If you're sure as others have said the o-ring was clean (not even a hair or single grain of sand!), o-ring groove was clean (I've heard the little sponge-tipped 'makeup q-tips' women use works best for this as cotton q-tips can leave fibers behind), o-ring is lightly lubed (silicone is just for friction reduction so it doesn't twist or kink while closing the case, not part of the seal itself, you just want it to appear a little glossy, not have an obvious buildup), etc. then here's the drill.

Pack the housing (carefully- wouldn't do to get any of it in the o-ring groove) with a towel or wad of paper towels, seal, and dip it into a deep sink with freshwater. Work each control a few times, noting if any feel harder to actuate than the others as they may have salt or sand in them, and lift the housing out of the sink after each control to look for water spots on the packing inside beneath that control. If none of them show any real spotting, then just let the housing soak for a while (you may have to weight it down) and try again, and look for any particular leak points around the o-ring seal as well.

Shallow dives are the most likely leak point for almost any housing, since you don't have external water pressure 'pushing' the shell together and increasing the pressure on the o-ring seal. That said, the Canon one-sided clip design is pretty good and tight on the main o-ring. I'd almost suspect (and this is only from having an A520 housing myself) one of the button shafts is a bit unlubricated, so on shallow dives, if the air inside the housing warms up, it can 'push' against the inner surface of the o-ring around the button and let a leak out that way. Or you push the button to use it and when it springs back out, the o-ring is sticking against the shaft and coming out with it a bit, so water gets behind it. Another maintenance tip I've seen others suggest (but not used myself, although it's filed in my good ideas category, not out of lack of belief in it) is to get some of the food-grade liquid silicone (or McNett makes one) and put just a tiny drop of it beneath each button as best you can and work it in by actuating the button. This helps keep the o-rings lubricated on the button shafts so this sort of thing can't happen.

If none of the diagnosis gives you any faith, though, get it serviced as others have advised! No sense adding task loading of 'camera worry' on top of any dive.

 

[BlueDevil]

Thanks for the great advice guys! I guess it should have been obvious to me that this leak must be associated with one of the many O-rings in the housing. I also hadn't considered the issue of shallow water being more likely to cause problems because of the lack of pressure holding the housing together. Interstingly on the first dive where it leaked it was some 25 min into the dive when it leaked. I would have thought it would happen pretty much straight away, but I guess it is possible that I pushed a button that I previously hadn't used on that dive.

I think I will ring my nearest Canon service centre today and ask what it will cost for a full service with inspection and lubrication (or even replacement) of all O-rings. I am a bit reluctant to attempt lubricating them myself and hoping for the best (I'm not too good as a handyman!) I will compare the cost of servicing against the cost of a new housing (approx $220 bought locally). It would not so much be the loss of money for the ruined camera that would bother me, but rather the loss of ability to take any underwater photos on a trip like this.

I guess it is not just these two incidents that has lost my faith in the housing. On my second ever dive with it, it completely flooded and destroyed the camera. The cause of the problem was a metal circlip which fell off one of the buttons as I was closing the housing (unkown to me at the time) and landed on the O-ring. With a metal clip sitting on the O-ring failure was inevitable - since then I have been very careful to inspect the O-ring through the perspex after I have closed it up. Fortunately Canon accepted that it occurred as the result of a fault with the housing and replaced the camera with a brand new one. This is one reason why I am now meticulous in my housing preparation.