DIR or not

[Andy Phillips]

Ahhhh Bob,

I have now had the joy of diving both steel and ali stages and, well, to be honest, I can't really see the difference in normal use. The only thing I'll say is the ali 10L is huge, the steel is much more comfy, but then bear in mind I wear the stages on both sides. This neutral / positive argument about steel and ali is a bit odd. The fabre light weight steel stages are neutral with about 50 bar in them, this works for both the 7's and the 10's. Full, I agree in water the steels are slightly more negative due to there smaller surface area, but, there really is not much difference, anyway, in the UK this is no bad thing as it gets you down the shot nice and quick.  

I guess my point is, you pays your money, you makes your choice, I can find little difference between the two under use.

Just an opinion,

Andrew

[Mark Chase]

Originally Posted by [b

Quote[/b] (Bob Cooper @ Mar. 01 2004,20:09)]If you have theoretically perfect weighting, you will be neutral at 3m with no gas in the wing, add a stage with about 50 bar in it and you would gain something like 700g(?) of positive buoyancy, I doublt if anybody could detect 700g of positive buoyancy!  

Luxfor cylinder 7ltr full -1.1kg
Faber light weight steel full -1.8Kg

Diferance 700grams

Do you think we would notice 700g negitave ??


Luxfor 7ltr cylinder empty + 0.6Kg
Faber 7 ltr Empty + 0.00

so 600g diferance empty but positive this time ??

Figures from Kevin Gurr Technical Diving from the Bottom Up page 31.

I watched my 7ltr tanks float neutrol with 100bar in in Stony Cove (much to my surprise. I also have taken my stages off on deco when getting back on a rib and watched them floating infront of me with 100bar in so I think the Faber light weights are on a par with the Luxfor 7's. but I dont know about the US tanks.

I think the GUE preferane on tanks comes from the Heiser steel tanks often used in the USA they are seriously heavy I used two 10ltr Heiser tanks in Gozo and was shocked at the weight of them I thaught they were 300 bar.

Andyp is bringing a 100m rated camera housing to our next big deco dive on the 14th March so I will try to get some pics showing floating tanks and a presure gauge.


ATB

Mark Chase

[dlegros]

Originally Posted by [b

Quote[/b] (wetlettuce @ Nov. 07 2003,15:51)]

Hi

Isn't yellow the new black?

So that's why I have one black fin and one yellow!

Dom

[Dominic]

Just to add - when I've cross-checked the numbers on Faber's website with my bouyancy calculator, most Faber cylinders appear to be +ve when empty, so presumably a lightweight Faber would be just as acceptable as an Alu?

[Fathoms Down]

Originally Posted by [b

Quote[/b] (Dominic @ Mar. 02 2004,11:37)]Just to add - when I've cross-checked the numbers on Faber's website with my bouyancy calculator, most Faber cylinders appear to be +ve when empty, so presumably a lightweight Faber would be just as acceptable as an Alu?

If you work out the bouyancy characteristics of the Luxfer and Faber 7ltr cylinders using the manufacturers weights and working pressures then the Faber swings from 0 full to +1.8 empty while the Faber swings from -1.1 full to 0.7 empty.

I must admit I've never dived with alu stages and haven't noticed much of a problem when diving with steel 7ltrs but I was interested if there was any other thinking behind the DIR guidelines.

Anyway, thanks to Bob for highlighting some things I hadn't thought about before.

[Bob Cooper]

Originally Posted by [b

Quote[/b] (Mark Chase @ Mar. 01 2004,22:20)]

Originally Posted by [b

Quote[/b] ]Andyp is bringing a 100m rated camera housing to our next big deco dive on the 14th March so I will try to get some pics showing floating tanks and a presure gauge.

I think I'm on the same dive (Defiant?), so perhaps we can do some kind of comparison?

Originally Posted by [b

Quote[/b] ]I think the GUE preferane on tanks comes from the Heiser steel tanks often used in the USA they are seriously heavy I used two 10ltr Heiser tanks in Gozo and was shocked at the weight of them I thaught they were 300 bar.

You're probably correct there Mark.

[Paul Beal]

Am I right in thinking though that, at the moment and with knowledge of the above, if someone was to book onto a GUE DIR fundamentals course and had Faber lightweight 7s with the intention of using them as stages they would not be allowed to?

Paul

[adam]

Hi,

On the Fundamentals course, stage bottles are not used-so it would not apply.

At Tech 1, there is no standard on which type of cylinder to use. I have no experience of diving Faber 7's as stages-nor will most DIR divers, but if they behave as you suggest, I can't see a problem. If however they preclude you from doing any of the required skills (which they shouldn't given the above), then obviously you would not be able to use them.

Personally, I switched from steel to Alu some time ago, and wouldn't go back!

Adam

PS. I can't find any link to buoyancy characteristics on the Faber site-can you give me the link?

[Fraser]

Hi Adam,

I think Dom was referring to using his own cylinder buoyancy calculator with the weights from the Faber site. Dunno if it's the same calculator, but you could try here:
Buoyancy calc

HTH,

Fraser.

[Lawrence Debono]

I agree with you there Pierre. Too many muscular males - not my cup of tea. I rather see some nice ladies with thongs even though that would get me in 5hit with the missus. I mean normal built ladies, not the muscular once either. Sorry I felt that women should be before diving. George seems to drum up some regimental rules and have every thing 100% perfect including the body of a diver. I'm afraid it isn't like that. Some are fat, some are thin, some smoke, some drink, some are stupid, some are crazy, some are paranoid.... and the list goes on.  

DIR or not - hmmmmmmm I vote for DMW.

 

Lawrence D