Which O-ring for which application ?

[trappist]

End of the season... time to change my O-rings... Well actually I never changed them so I figured I'd better do it before I loose my items ;o) And of course, I need help to get the right ones !

I have a few different applications...

1. Dive lamp - green Force Arrow 12
I kind of figured using Nitrile ones is way more than sufficient (I need metric sizes...)

2. Camera housing (Ikelite) - ooops never changed them in 7 years and still working like new... but should I try to beat the odds ? maybe not... I guess a nitrile should be good enough as well

3. spare save-a-dive... probably will go with Viton, so that I have not to worry, but what would be your advice on alternative ? I heard Nitrile is good too, what about EPRs ?

Any suggestions on which sizes I should go for ? This is really tough to determine as the old ones might have changed versus their original sizes...

 

[HenrikBP]

This might help you:

http://www.scubaboard.com/forums/repairing-your-own-gear/310236-diy-save-dive-o-ring-kit.html

Henrik

 

[trappist]

Thanks, that helps It looks like a pretty easy save-a-dive kit to make for only a few bucks !

The most difficult part for me is actually to determine the right o-Rings to use on my (very) old Ikelite housing... this was for a Canon G1 digital camera. I'm still happy with the pictures it takes, so I won't get rid of it - yet I tried the G11 (my bro just bought it with the canon housing) but I have to admit I do like my old G1 that I know by heart almost !

 

[jraitchi]

The easiest two ways are to give the manufacturer a call/email (if they're still around), or simply just try and measure the diameter and thickness.

I've had a few things-not dive gear-that neither of those worked...if it's a critical ring then you might have to get technical. Parker is the industry leader in o-rings, and they have a lovely couple hundred page design manual

Literature Result - Parker

 

[gcbryan]

I've found in general that any of the materials work with salt water and Buna N (Nitrile) is usually the most common.

Most o-rings are ordered by ID (internal dimension) and cross section or sometimes OD (external dimension).

It seems that in the range that we need with dive lights it's usually ID and then a standard cross section of about 2mm.

It's hard to find places to order just a few o-rings of a certain size but I'm still trying to figure all this out as well.

 

[trappist]

Well... I placed an order on AOPTEC and follow a few old threads (including Henrik's) on what would be the typical Save-a-sive kit, threw in there what I needed for my dive lamp and future DIY stuff I'm planning... Strange, I know my order was accepted but there so far I did not receive anything I sent them an email to check on the status, we'll see... I think I will be set for years if they do not get old...
I did not order the one for my ikelite housing though as I did not know which specs these are