Twin Set Choices

Right, I had a look through the archives, read various links so I know
what I really want is a O2 clean 12L steel manifolded twins. This of
course means buying the complete twin set and probably 2 new regs[1]
which is the most expensive option. However, this has got to compete
with the motorcycle due a major service + shims + chain + all fluids
and maybe tyres <ouch>

I quite like my current Aqualung Cousteau, never really had any
problems with it in the diving that I've done, so would be happy to
buy another set(s). Then again my daughters have got Scubapro Mk25 +
R380 and they seem happy with those regs. Everything else I ve used
has been school stuff abroad and TBH I suspect any balanced reg will
seem good compared to that.

I do have 2 10L cylinders which I'd bought originally for the girls
but they're not really big enough for the UK so I could twin those
either manifolded with the option to use the same manifold later with
a pair of 12L or use them as independents[3] but would they really
have enough capacity. My gas consumption has got better but although
I've managed a SAC of ~15 litres res in warm water it's closer to 20
in the UK with drysuit. The other potential problem with them is
they're marked for air, although I believe this can be over stamped by
a test house. I do really want to be able to use Nitrox in whatever
set I end up with.

My current Poseidon wing has a lift of ~25KG so that shouldn't be a
problem. The mounting of the twins means removing the current cam
bands and replacing with two longer ones. Then using a twin boot to
hold the cylinders together at the bottom[4] and or conventional bands
and a special adaptor. At the moment I heading towards the longer cam
bands, is that a good idea or not?

Enough rambling I guess, thoughts options welcome before I spend any
real money. This isn't an urgent project[5]. I was intending to be
sorted by Easter as I doubt I'll be doing much that could need the
extra capacity of a twinset before then.

[1] Assuming that I'll keep my existing AquaLung + Glacia for single
tank diving[2].
[2] Otherwise it's a lot of faffing about switching hoses.
[3] The cheapest option
[4] As always a good idea to remove the boots occasionally to check
fro corrosion.
[5] Except I have an opportunity to enrol on some twinset training and
having a twinset would be useful.

--
"reorganising, a wonderful method for creating an illusion of progress"
znvygb:Ian_Blakeley@ubgznvy.pbz (ROT13 all of it to mail me)

"Ian Blakeley" <boots@despammed.com> wrote in message
news:adlsqvs5c6lrdhg3cmc1afu3ol8l7u518o@4ax.com...
> Right, I had a look through the archives, read various links so I know
> what I really want is a O2 clean 12L steel manifolded twins. This of
> course means buying the complete twin set and probably 2 new regs[1]
> which is the most expensive option. However, this has got to compete
> with the motorcycle due a major service + shims + chain + all fluids
> and maybe tyres <ouch>

Ian,

Come and see me at the Dive show - I'll be on the Wittering Divers stand,
underneath the Inspiration and Kiss rebreathers - next to the twin sets &
weezles - leave your credit cards at home

/FAB

"Ian Blakeley" <boots@despammed.com> wrote in message
news:adlsqvs5c6lrdhg3cmc1afu3ol8l7u518o@4ax.com...
> Right, I had a look through the archives, read various links so I know
> what I really want is a O2 clean 12L steel manifolded twins. This of
> course means buying the complete twin set and probably 2 new regs[1]
> which is the most expensive option. However, this has got to compete
> with the motorcycle due a major service + shims + chain + all fluids
> and maybe tyres <ouch>
>
> I quite like my current Aqualung Cousteau, never really had any
> problems with it in the diving that I've done, so would be happy to
> buy another set(s). Then again my daughters have got Scubapro Mk25 +
> R380 and they seem happy with those regs. Everything else I ve used
> has been school stuff abroad and TBH I suspect any balanced reg will
> seem good compared to that.

I use the MK20 with a G250 primary and an R380 alternate. The MK25/R380 is
quite similar. It's an excellent combination for those that don't require
as many external adjustments. The R380 has one less than the G250. I think
it's cracking pressure that's missing. I've not noticed a problem.

I'm a long time USD user. I still have several of them and all have
performed flawlessly. They are not, however, as good as my Scuba Pro. They
just don't breathe as easily. Since you're used to one, it's probably not
an issue for you and there's nothing to day that your regulators have to be
the same.

> I do have 2 10L cylinders which I'd bought originally for the girls
> but they're not really big enough for the UK so I could twin those
> either manifolded with the option to use the same manifold later with
> a pair of 12L or use them as independents[3] but would they really
> have enough capacity. My gas consumption has got better but although
> I've managed a SAC of ~15 litres res in warm water it's closer to 20
> in the UK with drysuit. The other potential problem with them is
> they're marked for air, although I believe this can be over stamped by
> a test house. I do really want to be able to use Nitrox in whatever
> set I end up with.

The problem with using tanks you already have for mainifold twins is
normally the valves. All the manifolded twin sets I've seen have a reverse
side valve for the left side and both the right and left regulators have an
outleg opposite the valve handle specifically for the manifold. My normal
valves have neither. You may find that the valves cost almost as much as a
tank and valve together. You might consider selling your existing tanks and
using the proceeds to reduce the cost of ones specifically designed for
manifolded twins. Then again, UK valves may be different from what I"m used
to.

> My current Poseidon wing has a lift of ~25KG so that shouldn't be a
> problem. The mounting of the twins means removing the current cam
> bands and replacing with two longer ones. Then using a twin boot to
> hold the cylinders together at the bottom[4] and or conventional bands
> and a special adaptor. At the moment I heading towards the longer cam
> bands, is that a good idea or not?

I'm not fond of it. I suggest stainless bands and a plate/wing setup. If
it's time to twin, it's probably time to move up to a plate and wing as
well. Very few people ever regret making the change. You're going to need
the bands in order to protect the manifold. The tanks have to be held
firmly in place. I like the security of bolts over bands any day.

Lee

"Frank Bruce" <fbruce@cruelmail.com> wrote
> "Ian Blakeley" <boots@despammed.com> wrote in message
>>what I really want is a O2 clean 12L steel manifolded twins. This of
>>course means buying the complete twin set and probably 2 new regs[1]
>
>Come and see me at the Dive show - I'll be on the Wittering Divers stand,
>underneath the Inspiration and Kiss rebreathers - next to the twin sets &
>weezles - leave your credit cards at home

OK will do, I've ordered my tickets today and will probably be there on
Saturday. I'll get my daughter to hang onto my CC to save me from penury

--
Ian

"Lee Bell" <leebell@ix.remove.netcom.com> wrote
> "Ian Blakeley" <boots@despammed.com> wrote in message
>>Right, I had a look through the archives, read various links so I know
>>what I really want is a O2 clean 12L steel manifolded twins. This of
>>course means buying the complete twin set and probably 2 new regs[1]
>>
>>I quite like my current Aqualung Cousteau, never really had any
>>problems with it in the diving that I've done
>>Then again my daughters have got Scubapro Mk25 + R380
>
>I'm a long time USD user. I still have several of them and all have
>performed flawlessly. They are not, however, as good as my Scuba Pro.
They
>just don't breathe as easily. Since you're used to one, it's probably not
>an issue for you and there's nothing to day that your regulators have to be
>the same.

It was more a case of thinking of keeping my exisitng single tank regs as
they were that prompted me to consider 2 new regs. Although switching hoses
and regs on and off the 1st stage wouldn't be a huge problem it just struck
me that it's perhaps not a good idea to keep on doing this. I guess I am
assuming that I'll still dive the singles and that swapping the bits is
inherently a bad idea.

>>I do have 2 10L cylinders which I'd bought originally for the girls
>>but they're not really big enough for the UK so I could twin those
>>either manifolded
>
>The problem with using tanks you already have for mainifold twins is
>normally the valves.

You're right, new valves will be ~35% of the cost of new cylinders. A early
idea was to move the DIN valves from the 10L to my 15L cylinders which are A
clamp only. However, having checked the A clamp are 3/4" thread whilst the
DIN are 25mm. So I will most liley do as you suggest and sell the 10L and
buy dedicated twin 12L.

>>The mounting of the twins means removing the current cam bands
>>and replacing with two longer ones. Then using a twin boot to
>>hold the cylinders together at the bottom[

>I suggest stainless bands and a plate/wing setup. If it's time
>to twin, it's probably time to move up to a plate and wing

Having checked Poseidon's site it looks as if they recommend stainless bands
as well so either new wing and backplate or existing wing with the bands and
the same twins. I'll rethink this over the next few days , I quite like the
comfort of this wing but I guess the cost to switch isn't really that great.

--
Ian
PS hope this doesn't appear twice the PC crashed 1/2 way through 1st time