greasing your O rings!!

[divergal]

Sorry for the title!! I havent yet got my housing but am asking a question in advance! Now I realise that I have to be very careful to make sure the O ring seal is clean and free from hairs, grit etc but do I have to grease it every time (my book hasnt come yet and it may tell me in here!)

and another related question- what type of silicon grease do I use? I have a tube of general purpose silicon grease could I use this or does it have to be camera brand specific?? thanks

[Cussy]

As the late and great Jim Church once said "Love thy o-ring"!!

O-rings cost a few pounds, silicon grease costs even less, a flooded camera costs hundreds!! Through bitter and painful experience I grease mine every time, but there are others I know who hardly grease them at all. BUT, you can over grease them. The grease doesn't create the seal the rubber o-ring does, so if you have too much it allows water to by-pass the ring. So if I have to open my housing for something stupid, like I did last week as I hadn't attached the flash connector to the top of my camera properly, I just pass the o-ring through my fingers again to make sure the grease is evenly spread. If it needs a little more then apply a little more. It should just look shiny, not caked in grease.

The compatibility of grease and o-rings is manufacturer specific. I used to have Olympus and these had bright red o-rings that meant normal silicone grease wasn't compatible. I've now gone over to Ikelite and these are black rubber o-rings and I can use almost any grease. So before using general grease I would check out if it is compatible.

HTH
Rob

[Mark]

Greasing your ring, You can't beat the classic double entendres

I agree with what Rob says.

The grease will also dry out and will need to be removed before putting new grease on. Mine seems to be drying out quicker now, although the grease seems fine. The grease on my video housing stills seems as wet as when I applied it!

[TimIngmire]

On the other hand - I rarely grease mine and have yet to have a problem as a result. Also, I never remove the O-rings unless I have to but others remove them regularly eg during general storage, flights etc.

[Cerianthus]

I use Ikelite´s grease for my Ikelite housing. They mention that the wrong kind of grease may induce the orings to swell, leading to havoc. Not worth the risk for me. The grease costs very lttle..

Gerard

[Jules]

Originally Posted by TimIngmire

On the other hand - I rarely grease mine and have yet to have a problem as a result. Also, I never remove the O-rings unless I have to but others remove them regularly eg during general storage, flights etc.

Definitely dont leave your o rings compressed in storage. So wither remove them or leave the housing open.

I wipe mine often and regrease about once a month

[TimIngmire]

Originally Posted by Jules

Definitely dont leave your o rings compressed in storage. So wither remove them or leave the housing open.

I wipe mine often and regrease about once a month

You know, I've used the same orings for the last 2.5 years and have yet to have a problem - I've always kept them inplace and compressed.

The only leakages I've had are due to the port unscrewing.

Of course, I've tempted fate by saying all that!

Tim

[Cussy]

Tim
Is this a thing about polycarbonate vs. aluminium housings? I know of three people who don't grease, you included, and the common factor is Al housings.

Or is it you shiny Al housing users are just so darn rich it doesn't matter if they leak

Rob

[Cerianthus]

Cussy,

Ikelite always warnes very strictly that the grease is a lubricant, not a sealant. This counts for all housings, both the gems (the shiney metal bricks) and the diamonts (the see through housings)

on my old Ikelite housing (Minolta 7xi), Ikelte even reccommended not greasing the main O ring, but I see no reference to it anymore in my 20D housing.

With the ikelite ports, a bit of grease will help the port slide in. I had one port fail because I hurried it (but I saw it in time), gotta love that gradual shore entry...


Gerard

[Cussy]

Gerard,
But Ally housings are a lot more rigid than polycarbonate, so placing a flat back onto another flat surface with an o-ring indentation there is nothing to lubricate. My Ike housing is a lot more rigid than my old Olympus one, but it still flexes and the design means there is movement of the o-ring during closing.

I used to work in a lab where we used o-rings under high pressure, the equivilent of 4-5km depth of water. Never had an o-ring fail as all the metalwork was precision made.

Ikelite o-rings are standard rubber (butyl nitrile if memory is up to it). Most silcone grease should be fine. Sea and Sea and Olympus needlessly put in colours and this is why they claim you need special grease. You can buy an exact match of the large o-ring in an Ike housing for less than €1. A large tube of Dow Corning grease is similarly a lot cheaper than underwater branded grease.

Rob