O-ring - maintenance

by Mike Maloney

Reproduced from in focus 72 (October 2001)

There are no set rules when it comes to the maintenance of underwater equipment. Everyone does what they think is best and if their methods work all well and good. If they don't the outcome can be expensive so, over the years on many trips on liveaboards and at shore-based sites, I have carefully watched how other underwater photographers set up their camera equipment before diving and how they maintain it.

Approaches range from the really fastidious types who even take a magnifying glass to check there are not hairs or grains of sand on their O-rings to the really casual ones who just give a fleeting glance at their O-rings before they slap everything together. Surprisingly, both systems seem to work for them although I know which one I prefer!

Others grease their O-rings before a trip and that is that untiI they return. Not to be recommended in my view. Some take out the main 0-rings when they travel. This is all well and good but great caution is needed when you re-assemble your equipment after a flight of six or seven hours duration, or even longer. If you are jet-lagged and tired it is so easy to forget to refit the main O-ring before you enter the water, with disastrous results.

Though they might always be extremely fussy about their preparations, a disaster can be the outcome of tiredness and lack of concentration after a long flight. So my golden rule is always to be careful and avoid rushing your preparations for that first dive with a camera. Indeed, I always do my first dive without a camera so I can concentrate on checking that my weight and buoyancy are correct and that all my diving equipment is functioning correctly. Also, I have time to once again adapt to being in the sea. Remember, it might be your first dive for a long time.

As far as my Subal housing is concerned, I always remove the main 0-ring before a flight and also for storage at home. I keep it in a plastic bag inside the housing ready for assembly and also as a reminder to replace it before I dive. This way the O-ring does not take up a set shape and also is not squashed and deformed by any pressure.

I remove the back plate O-ring every time I open the housing. Then I thoroughly clean and lightly re-grease it. I always clean the O-ring groove, using toilet tissue. I only use the cheaper type because it does not leave any fibres, unlike the expensive, extra soft luxurious brands. My wife Jan always uses pure linen tea clothes to clean her equipment and that works for her. I never use cotton buds because I find they also leave fibres, which is not what you want. Other people run their 0-rings through their lips to clean off any hairs, etc before they regrease them.

Other accessible O-rings also require careful attention. Each time I change a port I clean both the O-ring and the seating. If you look at these rings carefully you will be surprised just how much in the way of fine sand particles can gather on them during just one dive, These fine grains are always present in suspension in the sea and seem to be attracted to O-rings.

On flights I do not remove the O-rings on the battery covers of strobes. However, I slightly open them and secure the covers in place with a strong elastic bond round the housing. Then there's no chance of forgetting to refit them.

At the start of a dive trip I always clean the seating and the O-ring of my Y5120 strobe, fit my eight lithium batteries and leave it in place until I need to change the batteries.

Blue O-rings are now fitted to all Sea and Sea units. They seem to become rather tight in the seating before removal. Indeed, they almost cling when you leave them in place for say a week's diving and photography. However, as the lith batteries have such a long life you may feel more comfortable if you remove the O-rings halfway through and clean and grease them before refitting the cover.

Careful attention needs to be given to the sync cord connections into the camera housing. I clean and grease them at the start of a trip then, if all works correctly, I leave them in place until it is time to strip everything down for the return home. Before assembly, I always make sure the sync plugs and their threads are clean and greased. Also, I lightly grease the shafts of the plugs into which the cables are inserted. If you do not do this they can seize, no matter how many times you rinse the unit in fresh water after each dive.

AI I my general observations refer to my method of caring for my Subal housing. Those relating to the strobes and sync cords apply to both Subal and Nikonos V connections as they are similar.
When I use my Nikonos, I clean and prepare the O-rings in the same way and use the same materials. However, when I fly I do not remove the main O-ring. Instead, I just release the back so the air pressures can equalise and hold it in place with a rubber band. Again, this is a way of ensuring I do not forget to replace the back.

A point which Peter Rowlands always stresses - he is an authorised Nikonos service agent - is that when changing fiIms you should always open the back with it facing downwards to stop any tiny droplets of water caught between the 0-ring and the back dropping into the main body or onto the delicate shutter blades, causing untold damage.

When I return home I reassemble all my equipment, clean all the 0-rings and seatings as I go along and then let them soak in fresh water for a couple of days. This includes the strobes as well as the housings and Nik V. While all the salt crystals are soaking off it is a good idea to work all the controls a few times while the equipment is in the water. This helps free the salt deposits which always build up even though some might be minute. They are the biggest enemy and must be washed off.