question about o-ring

[donnad]

hi, i got a bonica sea explorer camera and have a question. the manual says that the o-ring must be kept clean, because the slightest piece of debris or hair or anything can cause a problem with the seal and then you may flood. but it doesn't say how to do that. when you need to reload film, after you've let the camera dry of course, then would you gently wipe the o-ring with lint-free microfiber cloth like they sell in the auto dept. or what are you supposed to do after each time you need to open the camera? thanks for your help. another question. in between dives should i rinse the camera for a few seconds in the camera rinse bucket on board (going on a two day liveaboard to flower gardens soon), or do you let it stay in the rinse tank the whole time of the surface interval?? thanks,donna

 

[gert7to3]

Leaving your camera in the rinse tub for 10-15 minutes is not a bad idea. This way you can truly soak out any salts which may have gotten into the seals or mechanisms. Keeping it in the rinse tub between dives, assuming you don't need to attend to the camera, is usually a good idea too. The camera stays cool and protected. For instance, no one will set a tank on it. However if the dive boat is in rough water and there are some big metal video housings in there, removing it after a short soak would be wise. I alsways rinse the camera with bottled water after soaking, I carry a foam lunch bag to protect my camera and strobe.

For cleaning "O" rings I use lens wipes from an opticial shop (LensCrafters) or Permatex 4" x 4" lens cleaning wipes (P/N U53-984 from www.edmundsoptics.com). Best routine maintenance practice is to gently remove the "O" ring (don't stretch it). Wipe it down and clean the groove where it sits in the camera housing. Then gently apply a very even, light coating of the silicone grease recommended by your camera manufacturer. Reseat the "O" ring; make sure there are no fibers or particles on the "O" ring or in the groove. After closing the housing, you should see a continuous contact band of the "O"ring against the camera housing seal.

Dive interval service (reloading film, batteries, etc.) does not require fully removing the "O" ring. Rinse then dry the camera housing off. Perform your service, then close the housing. Wipe the suface your "O" ring seals against, close, then check the seal for fibers or particles.

Do not store your housing latched shut, as this may fatigue your "O" ring. Protect your camera housing from dust. Spare "O" rings are cheap insurance.

 

[discrepancy]

hi, i got a bonica sea explorer camera and have a question. the manual says that the o-ring must be kept clean, because the slightest piece of debris or hair or anything can cause a problem with the seal and then you may flood. but it doesn't say how to do that.

Before your dive, I would dig deep into the o-ring groove with a cloth to clean out any lint, sand or other rubbish. Then put a speck of lubricant onto your forefinger and rub it into your thumb and 2nd finger. Finally, pull the whole o-ring gently through all three fingertips. The nerves on your fingertips are very sensitive. A stretched o-ring will feel like a strangled chicken's neck, and a speck of sand will feel like a boulder.

When you're happy that the groove is clean and the o-ring is smooth, then close your housing and go diving. Remember to relax and smile - you can grin like an idiot for pure joy underwater, and noone sees it.

 

[Thalassamania]

O-rings work because pressure makes the seal increasingly stronger. I've always worried about leaving things in "low pressure" environments like wash buckets. I rinse my Nikonos or housing, gently blown it dry, and put it out of the sun. Any thoughts?

 

[fdog]

O-rings work because pressure makes the seal increasingly stronger. I've always worried about leaving things in "low pressure" environments like wash buckets. I rinse my Nikonos or housing, gently blown it dry, and put it out of the sun. Any thoughts?

I've seen more floods in the rinse bucket than anyplace else. My housings are only in the rinse bucket if my hand is attached.

All the best, James

 

[discrepancy]

I always imagined that flooding was mainly a danger of the deep, but Thalassamania and fdog (pigs can fly - spectacularly fast ) are telling us that the rinse bucket afterwards is maybe a bigger problem. Is that from gear getting knocked around badly in the bucket, our just being there?

 

[Thalassamania]

My feelings also, and there's physics to back it up!

 

[Thalassamania]

No, O-rings are not "sealed" by cranking down the lid. Presure deforms them and "stuffs" them in th crack. If there's no pressure gradiant, the seal is very weak, if there's a high pressure gradient and the o-ring is behaving properly the seal is very strong.

In the wash bucket the gadient is very weak, and if the wash bucket is warm to hot, as the air in the housing heats up, it may in fact pass through a phase where there is no gradient at all.

 

[fdog]

<snip> Is that from gear getting knocked around badly in the bucket, our just being there?

Yes to both! I look at the rinse bucket as a neccessary evil.

All the best, James

 

[Tortuga Roja]

I've seen more floods in the rinse bucket than anyplace else. My housings are only in the rinse bucket if my hand is attached.

Good policy!