Oceanic BUD/Atom/GEO O ring size

[mikeycanuk]

Tried going to the LDS to get some o rings for our Oceanic BUD's, no luck. I've searched here but not much luck. They are quite a thin o-ring. I'm also not paying $25+ for a kit either!!!!:shocked2:

 

[marcushall]

I have an ATOM 3.0 and although I haven't replaced it yet, I'm pretty sure that the o-ring size is -023. I did measure it at 1.185" OD, 1.064" ID, and .053" thickness, which seems consistent with a slightly stretched -023 o-ring (1.051" ID, .060" thickness). The next size of (-024 is 1.114" ID, which is already bigger than what I measured).

As I said, I haven't actually replaced this yet, but this is what I plan to use.

A table for reference can be found (among many places) at www.prepol.com/PPE-Uploads/Oring_sizes_AS568.pdf and one source for o-rings that looks reasonable (but I have not used yet) is at O-Rings - The O-Ring Store, We make getting O-Rings easy! .

 

[Pyro_]

I normally just order mine off of ebay. think it was 10$US for oring and battery kit plus 2 or 3$ shipping to toronto.

 

[mikeycanuk]

I might have to go that way too. What bothers me is someone has figured it out as that kit is simply a battery, grease and an o-ring that someone has put together. Still better than the Oceanic official one for $20+

---------- Post added April 1st, 2015 at 03:29 PM ----------

Hell if I didn't just waste 30 minutes at the the local o ring store only find they don't sell that size. Either to thin or too thick. Where are Oceanic sourcing these from?

 

[Arturo]

Marcushall: I don´t know about the BUD but I am very sure about the Geo and the Atom. Neither of these two use a AS 568A standard Oring. That rules out O23 and O24. The real size is ID: 27.5 mm; CS= 1.2 mm- An odd size, indeed, that you can get with the battery and some silicon grease on ebay from a person that sales "almost" any dive watch kit there is. About $ 10 as Pyro noted.

 

[marcushall]

I did pull the o-ring off of my Atom 3.0 computer and measured it as .053" (1.3mm) thickness and 1.064" (27mm) ID and 1.185 (30mm) OD. If this is stretched and still 1.3mm thickness, I don't see how it could have started as 1.2mm. The AS568A-023 size is 1.051" ID and .070" thickness, which conceivably could stretch to 1.064" x .053", although the thickness does seem a little too thick.

Now, I do see that my ID + 2*thickness != my OD, so there's certainly some inaccuracy here, but I have no idea how to reconcile my measurements with any O-ring size..

 

[Arturo]

Marushall: As I told you, it is not an American Standard Oring size. It´s metric (incidentally, is the same Oring used by other computers, such as the TUSA IQ900 Zen, Aeris Manta and Aeris F10). I´ve replaced the battery in quite a few TUSA Zen, Manta´s and, of course, Atom´s, always used the referred Oring, pressure test all of them to 160 ft and never had any leaking issue. You probably can not reconcile your measurements with the original dimensions of the Oring because both, ID and cross section have changed. The ID by stretching and the CS by flattening because is under pressure between the body and the rear hatch of the computer.

 

[mikeycanuk]

I went into this store http://ablesealanddesign.ca/category/O-Rings/2.html

They spent 10 minutes trying 4 different o rings, none of which fit. They carry domestic, European and Japanese sizes.

I bought the cheaper eBay kits. Bugs me that I'm overpaying just because someone figured out the size, but where from.?????


Sent from my iPad using Tapatalk HD

 

[Arturo]

Mikeycanuk: Breath deeply and relax. You did the right thing. After all, paying $ 10 for a battery (which itself probably cost you about $ 5 in Wallgreens) and the right Oring for your $ +200 computer, doesn´t seem that expensive to me. After all, you have to do that only every two years. Renting a tank for a single dive, at least in Florida, costs you $ 10.

 

[marcushall]

Marcushall: I don´t know about the BUD but I am very sure about the Geo and the Atom. Neither of these two use a AS 568A standard Oring. That rules out O23 and O24. The real size is ID: 27.5 mm; CS= 1.2 mm- An odd size, indeed, that you can get with the battery and some silicon grease on ebay from a person that sales "almost" any dive watch kit there is. About $ 10 as Pyro noted.

Yes, I have pulled out the o-rings from both computers I have (mine and my son's), and I do think that the o-ring is 1.2mm CS to the accuracy I can read it, and I read the inside edge of the hatch at 27.46mm, and the ID of the o-rings at 27.17mm for one and 27.53mm for the other, so this is all consistent with the size being 27.5mm ID.

Now, where to find such a size for sale! Is the $10 e-bay really the right size, or is it perhaps a 1.2mm x 26mm that I can readily find and would stretch over the hatch, or a 1.2mm x 28mm that I can also find that would fit loosely over the hatch and would probably compress just fine, or is it actually 1.2mm x 27.5mm? (I can also find 2mm x 27.5mm, so 27.5mm ID isn't totally off the wall). But, I can't find any o-ring supplier that makes 1.2mm x 27.5mm...

BTW, you mention pressure testing after installing the o-ring. I'm curious how this is done? I read that the o-ring may not seal against air, so I presume you submerge it in water, but if it fails, doesn't that flood the computer? Can the testing be done using some cleaver technique so that the computer won't be flooded if it fails? Thanks!