Sea&Sea O-rings

Need some helps to get o-rings to service my MDX-D300. Is there any online store selling them? I don't mean the housing, port or strobe o-rings but the knobs and buttons. Thank you.

There are loads of online stores selling o-rings. But you may not find any stores selling 'kits' of them specific to your housing.

Your best way is to strip a couple of buttons out - identify the component o-rings and then buy them.

An example of another question on this subject was answered by me here.

The data that I most use to match and select o-rings is here though I tend not to purchase from these guys directly - there are likely to ask you how many million you want !

To be honest I prefer the printed copy of the above - but don't see it around much any more.

BTW the design guide section in here on machine dimensions for o rings is excellent data if you ever get into making your own stuff.

Paul C

Thank you Paul for the very informative reply.

Getting o-rings of similar sizes will not a problem but getting them with the correct hardness could be. It's unfortunate that Sea&Sea wouldn't sell o-ring kit in my country (Singapore).

O-rings that are not 'standard' are somewhat rare.

Standard hardness is 70 durometer.

The usual reason to go harder is for high pressure / dynamic applications where extrusion of the o ring may be an issue. In this context high pressure is probably > 200 Bar. Even scuba tanks and valves are 70 Dur and given the amount of abuse they get failure is rare.

Even in these high pressure designs back up PTFE rings are probably a better design bet than harder rings.

Your housing is only rated to a fraction of that so the rings are not likely to be harder than standard.

Softer than 70 Dur is possible - some back designs seem to use them - Subal for one - I must admit I am not quite sure why - but I would _guess_ that it could be that being softer they deform a little more and compensate better for the unequal sealing forces provided by only say two opposing latches.

Again for the knobs and buttons this should not be an issue - the buttons are precision made and dimensionally accurate (hopefully!) as are the shafts. If they are corroded or salt filled then that needs sorting or premature failure will be an issue.

So I would be surprised if Sea & Sea use any other than standard.

In case anyone else is going this way - Ikelite is a bit different - they seem to use Quad Ring rather than O-Rings in many places.

Paul C

Paul C