Steel / aluminium for pony cylinders?

I've been doing a bit of reading about the relative advantages /
disadvantages of aluminium and steel for a pony, and most seem to suggest
aluminium is preferred because of better balance and bouyancy
characteristics. I was thinking about it, had a look around to find prices,
but for something so highly recommended there are very very few shops that
actually sell aluminium cylinders in the UK - in fact only GoDive seem to
sell them from the shops I know.
Is there some other factor i'm missing as to why shops don't stock them,
should I just stick with steel like most seem to (despite almost all advice
to the contrary)? Are there any disadvantages to aluminium for a pony?

By the way, I will be getting a pony, and it will be back mounted to the
main cylinder - that won't change now, i've already bought the regs and
clamp, just need a cylinder to go with it. And please only advice on how
the cylinder would be useful for a pony in the above situation, not "this
other type won't be good for a pony, but will be great when you go to
twinsets with stages" type answers. :o)

Ta!

David

Its spelled Buoyancy

"David Walker" <wbsdavenews@hotmail.com> wrote in message
news:boph9p$1fi$1@wisteria.csv.warwick.ac.uk...
> I've been doing a bit of reading about the relative advantages /
> disadvantages of aluminium and steel for a pony, and most seem to suggest
> aluminium is preferred because of better balance and bouyancy
> characteristics. I was thinking about it, had a look around to find
prices,
> but for something so highly recommended there are very very few shops that
> actually sell aluminium cylinders in the UK - in fact only GoDive seem to
> sell them from the shops I know.
> Is there some other factor i'm missing as to why shops don't stock them,
> should I just stick with steel like most seem to (despite almost all
advice
> to the contrary)? Are there any disadvantages to aluminium for a pony?
>
> By the way, I will be getting a pony, and it will be back mounted to the
> main cylinder - that won't change now, i've already bought the regs and
> clamp, just need a cylinder to go with it. And please only advice on how
> the cylinder would be useful for a pony in the above situation, not "this
> other type won't be good for a pony, but will be great when you go to
> twinsets with stages" type answers. :o)
>
> Ta!
>
> David
>
>

David Walker wrote:
> I've been doing a bit of reading about the relative advantages /
> disadvantages of aluminium and steel for a pony

If you're clamping it the metal makes no odds at all. If your
side hanging things everybody seems to say 'Go for Ali
as it has better buoyancy' but I hate the things bobbing up
under my arms and getting in my way. My steels stay
tucked in underneath and are predictable, not changing
where they want to sit dependent on contents.
When you're climbing the ladder they both sadly weigh
the same which is where it realy counts.

nigelH

> Its spelled Buoyancy

For 2.25am, you're lucky it even had the right letters in!

Although "its" should really be "it's".
And 'spelt' sounds much better than 'spelled', although both technically
correct...

Now we've had a little spelling test, any idea about the original question?

David

David Walker wrote:

> Is there some other factor i'm missing as to why shops don't stock them,
> should I just stick with steel like most seem to (despite almost all advice
> to the contrary)? Are there any disadvantages to aluminium for a pony?

A lot of shops discontinued selling ally cylinders after the Luxfer
problems. You might want to read:

http://www.divernet.com/news/items/luxfer140600.htm
http://www.wahoo2001.com/Diving%20in...explosions.htm

If you're not going to side-sling the tank, there's no reason not to
use steel.

- Keith

> I've been doing a bit of reading about the relative advantages /
> disadvantages of aluminium and steel for a pony, and most seem to suggest
> aluminium is preferred because of better balance and bouyancy
> characteristics.

Unless you are in the fortunate position of not needing a weightbelt already
then a steel cylinder will suit you best. A steel cylinder will add a small
amount of weight to your back. A 3L steel cylinder can be easily side slung
later - they really do not weight enough to worry about.

Cheers
Matt.

David Walker <wbsdavenews@hotmail.com> wrote:
> I've been doing a bit of reading about the relative advantages /
> disadvantages of aluminium and steel for a pony, and most seem to suggest
> aluminium is preferred because of better balance and bouyancy
> characteristics.

That may have been true in the past but I was recently looking at stages and
found that there was no buoyancy difference between the current EU Luxfer and
Faber 7l cylinders (visit the manufacturers web sites to get the cylinder
specs and then work out the buoyancy for yourself or visit
http://www.subaqua.co.uk/cgi-bin/cylinder-buoyancy.cgi if you are feeling
lazy and want to check for yourself). Ok, I know the calculations are
'perfect' calculations but they give a very good indication.

With that to one side, I would recommend a steel pony as they weigh less
out of the water (but are slightly more buoyant in the water), are more easy to
come by and, generally, cheaper

Nick

On Tue, 11 Nov 2003 07:55:04 +0000 (UTC), "Nigel Hewitt"
<nigelh@REMOVETHISnigelhewitt.net> wrote:

>David Walker wrote:
>> I've been doing a bit of reading about the relative advantages /
>> disadvantages of aluminium and steel for a pony
>
>If you're clamping it the metal makes no odds at all. If your
>side hanging things everybody seems to say 'Go for Ali
>as it has better buoyancy' but I hate the things bobbing up
>under my arms and getting in my way. My steels stay
>tucked in underneath and are predictable, not changing
>where they want to sit dependent on contents.
>When you're climbing the ladder they both sadly weigh
>the same which is where it realy counts.

I use the rule steel on back, ali at side but that's just me.

Laz

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A foolproof method for sculpting an Elephant:
First, get a huge block of marble. Then, chip away
everything that doesn't look like an Elephant.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Change "nospam" to "ntlworld" to reply.

On Tue, 11 Nov 2003 09:42:50 +0000, Keith S. wrote:

> If you're not going to side-sling the tank, there's no reason not to
> use steel.

And it doesn't really make a lot of difference with a 3l anyway.

Jason