On 11/2/2021 at 7:16 AM, waterpixel said:
In about 200 dives with my housing, I probably have greased the o-rings 3 times. I always make sure nothing is in the way but if the o-ring safely sits in the housing, why take the risk of taking it out?
Different housings will have different requirements and the dive site makes a difference as well. I believe you have a Nauticam A7III rig, that housing uses a face seal, which is compressed by water pressure on the housing back. Technically I think this does not need lubrication - certainly for the similar ikelite o-ring they recommend no lubricant, though Nauticam state in the manual to lube the ring. The o-ring sealing face is well exposed and easy to inspect and wipe off if required.
I have the Nauticam EM-1 MkII housing which is a clam shell style with the o-ring in a groove on the back which needs to slide into the housing as you close the back. This o-ring needs to slide forward due too water pressure until it reaches the inside of the groove where the water pressure compresses it against the front half of the housing and the inside edge of the o-ring groove to form a seal. This o-ring absolutely needs to be lubed and be able to slide without hanging up. Because water needs to get in to seal it invariably brings in grit on silty shore dives I am often doing and it always has big water drops on it. So that o-ring gets cleaned each time I open the housing.
I have INON strobes and while the cap provides a tight fit, grit gets into the o-ring and if it doesn't salt water gets in. Even after a 2 hour soak the water trapped there is still salty and a day or two later salt crystals form which can damage the o-ring. So that gets a clean and grease every battery change.
I have an INON torch the cap for battery change has double o-rings and the lip comes up tight against an external rubber ring. I never find grit or water up against the o-rings on that system so the the o-rings get a quick inspection and are removed and greased/cleaned about once a year.
I don't believe there is a one side fits all for o-ring maintenance and people should be guided by their experience - start off cleaning regularly and scale back if you find that the o-rings are always clean. I think the risk of o-ring damage is possibly over stated, they are quite rugged if you don't over stretch them and remove them carefully with a proper o-ring pick.