Carbon Fiber Bottles

[jlillest]

Ok, next fun discussion. I'm interested in purchasing some carbon fiber cylinders for diving and am looking for suggestions on the best way to find and purchase them. I'm well aware of a small number of online vendors that sell certain types of CF bottles and they're on my list.


I'm looking specifically for bottles in the 2L to 9L range. On the small end, I'm happy with 200bar/3000psi to use with Oxygen, but towards the larger end I'm looking for at least a 300bar rating.


Which unit I dive, how I set up my gear or how bad I'll look in photos diving CF are not things I'm worried about discussing here, I'm mainly just trying to find good bottles to dive that I can afford without taking out a second mortgage.

[tbone1004]

why are you wanting to use them? Please remember that these are not considered durable bottles. You will want to check for cracks after every dive on the epoxy which won't cause a catastrophic failure, but water ingress will eventually destroy the inner portion of the composite. Best bet if you are hell bent on using them is finding SCBA bottles and getting a couple valves machined to their threads since you will be replacing these fairly frequently

[michael-fisch]

New CF tanks can only be hydro'ed once. Skipping Hydro for a few years in order the lengthen the tank life won't work either since CF tanks have an exp date..
There are legitimate reasons to use CF tanks, but
The first scratch going all the way through the paint is grounds to fail the tank. If your current stage tanks still look pristine after years of use cavediving, then buy CF tanks.
If they look as bad as everybody else's stage tanks, then CF tanks are not for you.

Michael

[Brad_Horn]

There are two types of CF cylinders available on the market: those rated for underwater use and those not. By far the greater majority sold to divers are not designed or rated for use in water...... If they are being sold cheaply and originate from China they probably have the safety rating of a live hand grenade. AFAIK none of the Chinese made CF cylinders on the market meet any actual certification standards but they are 'cheap' and therein popular within certain SCUBA circles. https://www.scubaboard.com/community...chased.538001/

To put that pricing in perspective, OSEL offer a CE Certified light weight carbon wound cylinder. 2 litre water capacity, 300 bar working pressure. M18 thread. In Oxygen Service. Manufactured by SCI in the US. For basically cost purchase price at US$570 a cylinder and you'll need an oxygen clean M18 valve on top of that and shipping from Scotland. Ten year cylinder life. And only reason they are that cheap is they are extras from a large cylinder order; which was the MoQ from the manufacturer. And as above you want to keep them in a neoprene sleeve to protect the wrap still when diving and transporting.

If you want 9L CF 300bar cylinders certified for underwater and oxygen service, send OSEL an email on sales@opensafety.eu as the military use them but expect pricing well in order of $1k plus per cylinder.....

Or else contact the limited number of US cylinder manufacturers such as SCI who make dive rated CF cylinders and buy direct or through their local distribution chain.

[OFG-1]

Just go ahead and bite the bullet, buy yourself some inconel spheres.

[jlillest]

New CF tanks can only be hydro'ed once. Skipping Hydro for a few years in order the lengthen the tank life won't work either since CF tanks have an exp date..
There are legitimate reasons to use CF tanks, but
The first scratch going all the way through the paint is grounds to fail the tank.

Not entirely true any more. Most CF tanks I've seen are DOT-legit for either 10 or 15 years, with 5 year hydros. I've also seen DOT tanks with other hydro schedules, and some CF tanks with lifetimes up to 30 years.


Certainly they're more fragile than full metal tanks, but given their use and abuse in the fire service, I'm inclined to push back on your fragility argument. I've personally used and abused them (SCI & Luxfer brand tanks) and only seen minor scrapes. The one failure I've seen was totally attributable to negligence.


Regardless, I'm aware of the pitfalls of CF tanks and I'm just hoping the forum might be able to provide information on procuring good tanks at a reasonable price, not discussing all the potential problems of using CF for scuba.

[jlillest]

Just go ahead and bite the bullet, buy yourself some inconel spheres.

If only I had the money...

[gschaut]

Fire Service has been using carbon fiber tanks for a couple decades. We beat the @#$ out of the tanks on the job. We only rarely have to scrap a tank due to physical damage. The exterior epoxy layer is very durable. We use the tanks because they are extremely light weight, a bonus for firefighting on land. But not so much in the water. The tanks will be positively buoyant, and you will have to compensate with extra lead. The only possible use I can think of for CF tanks is for a cave exploration where you have to carry the tanks thru miles of dry cave to reach the dive site. The tanks are lighter, and you would only have to carry ONE set of lead weights. So that scenario could save a lot of weight schlepped thru the cave.

Of course, with rebreathers, we no longer have to carry tons to tanks into a cave to make multiple dives at a distant dive site.

[rddvet]

Call Hydro Dave. Everytime I?m at his place he?s got multiple cf tanks sitting around for service. I?m sure he?ll have more info than any of us and can probably tell you where to get them


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[NOLAcaver84]

Call Hydro Dave. Everytime I?m at his place he?s got multiple cf tanks sitting around for service. I?m sure he?ll have more info than any of us and can probably tell you where to get them


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Who is Hydro Dave?


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