Manifolds for twinning [Archive] - BSAC Scuba Diving Forums

Adrian Kelland

01-05-2006, 23:02

You will probably need new vales, so really a complete new set.

The diameter of the cylinders matters. The pitch between the two once you have the twin bands on is what you need to measure.

Some bands have a poor reputation, some good. Likewise with the manifolds. MDE seem to be popular for ease of turning during shutdowns.

Let's put the horse back in front of the cart. Why do you want twin 10s Luke?

Adrian

Matt-75

01-05-2006, 23:52

This is probably not the answer you're looking for.

Because if i go indy twins i need to fork out more cash for another set of regs (which i currently can't really afford). The pony uses DIN, which i suppose i could use, but it has an inferior 1st stage compared to the DS1 i have on my atx40's. So ideally a manifold set with an A-clamp fitting would be good.

Why do i want twin 10's, actually its not a question of why i want them. I already have two 10L cylinders with A-Clamp valves. I got them so when im down in Wales i can get a couple of dives in without having to find somewhere with a compressor. Also my sister uses 10L tanks, so she can use them for dive with me.

Also im playing with idea of using them inverted, but i really need a DIN 1st stage to be doing stuff like that.

So i guess the main answer is to stay at 20m for longer. With the completion of a basic nitrox course inside a month, i have extended no stop limits after that for any dives i do (as long as i can find a buddy who dives twins). But yes, i have two 10's, it was the original reason i bought my wing with twinning bands, because i knew i'd move that way eventually, and i managed to pick the 10's up for cheap.

David Walker

02-05-2006, 00:13

I don't understand what regs you've got... usually the only difference between the regs for indy twins vs manifolded is the addition of an extra gauge... possibly an octo on one side too, but if you've got a pony you must have enough second stages for that anyway?

As for making them manifolded, if you really want to then you'll need a new valve/manifold set, and almost certainly a set of steel bands - you *can* get away with a double boot, but its really not recommended. MDE valves are good, i've got Agir ones and they're fine too. I'd go with Agir or similar bands too - the wide ones rather than the piddly little thin ones you often see - the Agir ones at least are no more expensive than any of the narrow bands, but there'll be others too.

If the tanks are old though, you'll need to check the threads etc, and probably need someone to put it together for you - might as well get them O2 cleaned at the same time if you're doing nitrox. If the tanks aren't a perfect match or are particularly old, you'd be better just buying a new full twinset.

That said, if I were you I wouldn't bother yet. You shouldn't be finding you are running out of air particularly quickly at 20m on a single cylinder, and if you haven't done many dives you'd be better just getting some more experience and getting your breathing rate down before switching. And if you progress onto the things you say you want to do, then you'll probably find you rather quickly want 12's rather than 10's and so need to double the expenditure.

David

Matt-75

02-05-2006, 00:25

AndyDavis

11-05-2006, 10:42

I considered getting a 12L instead to add to the one i have, but its a bit to soon for that much gas. Next year when ive made it to extended range level (or whenever i do the course, when im happy with diving to a point where twin 12's are going to be useful). For the minute 10's should be sufficient to take me through all nitrox and deco courses, and i suppose eventually i could relegate them to stage bottles.
Matt

Don't forget, having twin 12s will allow you the option of eeking out 2 'normal' dives from one full twinset (as well as the option of 1 'extended' dive).

IMHO, they offer more flexibility to your diving and cover a convenient gap between twin10s and twin15s. This is particularly useful when you dive from a day boat and don't have the option of refilling or changing cylinders (like you would do on a single setup).

One alternative for you would be to use the twin10s and maintain your 12litre tank for decanting across gas for a second dive. This is more effective if your 12l was a 300bar tank though.

Changing from a-clamp to DIN should be relatively easy. It would also allow you to fit an isolator between the valves (having the option never hurts!). If this didn't match your reg configuration, then you can normally have an a-clamp 1st stage converted to DIN relatively easily (just a case of your LDS replacing the connector).

Chris Cherrington

11-05-2006, 11:30

Let's put the horse back in front of the cart. Why do you want twin 10s Luke?

I have to ask the same question Adrian. Why on earth would this be appropriate equipment for an OD??

I took my SD exam last wednesday. Totally failed it ....

Extended range next year????

Mmmm....

Chris

Woz

11-05-2006, 13:21

Good valves:
MDE
Scubatec/Dirzone/Agir

Crap valves:
SanOSub

Good bands:
SDS
Agir
V4Tec

Crap bands:
Beaver
Hydrotech
Custom Divers

You can't twin up properly on the cheap. Better off twinning up indies at the moment. And possibly doing alot more diving before even starting to consider lugging around 2 cyls on your back. You can do anything up to 35m no stop on a single quite happily. Twinsets are not something to be taken lightly (hahahahaha).

Karim

11-05-2006, 13:47

As an Ocean diver which i assume you are? Dont you think this is all overkill? How about first getting Sportsdiver under your belt and actually achieving depths below 20m? This way you will be able to see the advantages of using twin 12s and you will better understand your air considerations? I personally find that a single 12 is plenty for Ocean diver depths.

I just get the impression that you may be wasting your cash getting twin 10s only to upgrade later to 12s which offer better flexibility? However thats my opinion, nothing can replace experience even if you do achieve extended range by next year.

good luck though

Steve Walsh

11-05-2006, 16:02

I got twin 12s before completing SD, mainly because at that time I had the available funds but mainly because I knew where I wanted to be with my diving in the future.one other big thing is the redundancy that they can give you if used correctly.

I bought them from the DO and he interviewed me for them, and only sold them to me when he was satisfied it wasn't just deeper diving I wanted to do but increasev the safety factor in a dive.

Chris Cherrington

11-05-2006, 16:19

... increasev the safety factor in a dive.

There are many (I am one) that would query the increased safety factor of using such inappropriate equipement.

Chris

Steve Walsh

11-05-2006, 20:31

There are many (I am one) that would query the increased safety factor of using such inappropriate equipement.

Chris

read ST5,

Dangerous Dan

14-05-2006, 13:53

From the feeling I get from your previous threads I would not advise you to go twins yet, I mean you mention it yourself that if your buddy is not diving twins then obviously your bottom time is limited to the same as theirs anyway, you say your strapped for cash so why not spend the money on getting experience and bringing your SAC down that way, instead of just covering up the problem with more gas.

Theres still a lot of time to be spent and stuff to see at 20 metres on a single cylinder.

Not having a go, just dont want to see another statistic because someone rushed to a twinset.

Paul Watts

14-05-2006, 16:00

Adrian Kelland

14-05-2006, 16:29

Don't fall a vistim to fashion...

Most of the techie stuff is just that, fashion.

My advice, go dive, enjoy your diving, keep it simple enjoy your diving, oh did I mention, go divr, enjoy your diving.
I don't think it is fashion Paul, but it is certainly not the majority of diving.

Adrian

Paul Watts

14-05-2006, 17:03

:cool: I don't think it is fashion Paul, but it is certainly not the majority of diving.

Adrian

Adrian,

For many NEW divers they (as I was) are sucked into wanting all sorts of kit. A lot of the time it's a need to look the part, fit in, be the same as others... I was no different.

On the whole the the only problem is that it's a cash drain. However, if newer divers concentrate on diving basic scuba, feel comfortable with the ket they have and then move on, they're more likely to purchase kit they need for the job and probably get more diving done in the process.

There is no doubt that a big part of selling/buying dive kit is fashion. Marketeers love it. All in black, whats that all about? fashion!

There's nothing wrong with buying the best kit for the job or the best kit money can buy if you can afford it. Quite often tho it's purchased because their mates or group have got similar or to make a statement, that's 'fashion'

Adrian Kelland

14-05-2006, 17:30

There's nothing wrong with buying the best kit for the job or the best kit money can buy if you can afford it. Quite often tho it's purchased because their mates or group have got similar or to make a statement, that's 'fashion'
That I agree with Paul. I wonder how many can explain a particular choice apart from 'It's what the instructor uses, so it must be good."

As for black, well what is the point of colour in most UK water? Every one seems to be a shaddowy grey :D

Adrian

Janos

14-05-2006, 17:53

For many NEW divers they (as I was) are sucked into wanting all sorts of kit. A lot of the time it's a need to look the part, fit in, be the same as others... I was no different.

Definitely. Especially so when reading t'interweb and it seems that most divers dive twinsets or rebreathers. When actually 90% of divers are on a single or a pony.

Hold on. I feel a poll coming on.

Janos

Paul Watts

14-05-2006, 19:16

ofcourse I'm only trying to defend the flouro pink flashes on my bcd and matching suit.!!! :rolleyes:

I guess if someone gets pleasure following others, belonging to a specific group or wants to be seen as a <type of> diver there's no problem, their choice.

I do think tho for some people it takes over their diving. We all read the threads of some participant on some fora having an almost obsessive need to acquire certain style of kit. Again their choice, if it's that that gives the pleasure.

However, I see it every year with new diver intakes, there's always one that will have to have a certain style kit spending '000's only to give up and sell it the following season...

I don't wish to give the impression that new divers shouldn't buy the best kit thats available or should follow a style of diving until they have dived for ever. Moreover decide what you want, to dive or to spend...

For me, I've dived pretty much the same config for 12 years or more, a little adjustment here and there... why, I'm comfortable with it and it works, I should also say that my diving hasn't changed too much in that time either. By the way, it started blcak and has gone a teabag brown colour!

The young man who's looking to twin up. If you really think you need the comfort or quantity of additional air, if you have access to someone who will assist/train you, then why not put them together and use them.

On the other hand, stick to a config you know, stay within the limits that your skills and kit permit and keep diving until it becomes second nature; as your diving demands, persue the training and kit you need. That way, you'll enjoy your diving more, won't waste your dosh and will stay safe.

Best wishes whatever you choose....

Chris Cherrington

14-05-2006, 19:44

...When actually 90% of divers are on a single or a pony.

I dived for a long time on a single but I doubt you would get a lot of BT from just a pony...

Chris

Matt-75

15-05-2006, 02:42

Sorry, havent actually followed this thread since i started it.

For clarification, i now have an individual twin 10L setup.

For when i dont want to stay down for long amounts of time i have a 12L and 3L pony.

With that many cylinders it also means i can do 2 or 3 dives in a day without to much of a problem.

I actually dont need anymore kit at this point. I have sufficient kit for everything i may want to do now, and in the future, although the whole manifold thing has gone out of the window. Its better i pick it up now, so if i need it next year its their ready for me. I needed the second reg set for the pony anyway, so having two 10L's is just a bonus. As for getting 12's for when i go that way, well i only need one more, and you can pick them up on ebay in test for not much nowadays, so i'll leave that for another day.

The whole redundancy issue is actually a big part of it, its not just about me going to 35m every week after i get SD signed off, i'd actually like to have a bigger safety margin for in case i ever need it, and frankly another air cylinder of the same size provides that without to much of a problem.

For the information of those who think i have high SAC, its currently 13, i can maybe get it to 10 with more practice, but i usually use 15 or 20 for calculations.

Anyways i could say a lot more, but i wont, because im slightly drunk and would just end up running my mouth, which benefits no one.

JimW

15-05-2006, 10:03

As for black, well what is the point of colour in most UK water? Every one seems to be a shaddowy grey :D

Adrian

Ever wondered why the Inspiration is a bright flourescent yellow and definitely NOT "techie black"? :rolleyes:

Me too, until I asked Martin Parker himself.
He sees the yellow as a safety factor, for descent in particular. If your buddy drops down below you during descent (for whatever reason) you don't have bubbles you can follow and so a black casing would be well nigh invisible (several million years of shark evolution make use of this phenomenon) whereas a bright yellow casing gives you more of a chance to see them.

Jim:cool:

Adrian Kelland

15-05-2006, 12:19

Ever wondered why the Inspiration is a bright flourescent yellow and definitely NOT "techie black"? :rolleyes:

Me too, until I asked Martin Parker himself.
He sees the yellow as a safety factor, for descent in particular. If your buddy drops down below you during descent (for whatever reason) you don't have bubbles you can follow and so a black casing would be well nigh invisible (several million years of shark evolution make use of this phenomenon) whereas a bright yellow casing gives you more of a chance to see them.

Jim:cool:
Gives good contrast for the free shovel too :D

Nick Kay

15-05-2006, 13:40

Two different parts to thia:
1. SDS bands and quick release system. Also get their single cylinder adaptor

2. Don't see the problem with "going twins" early, except for:
2a. You'll more than likely need to upgrade from std BCD to a wing (lift)
2b. Plus you'll need to buy an additional 1st & 2nd stage
2c. You'll need to sort out weighting & trim

My son was SD when he moved on to twins. However, we went out about it in a structured way:
1. Moved from BCD & 15L to Wing & 15L (single 1st stage, two 2nd stages)
2. Moved from Wing & 15L to Wing & Twins 10s (single 1st stage, two 2nd stages)
2= Nitrox course
3. Added a 5L stage cylinder
4. His next step will be to move to twin 1st stages each with one 2nd stage

He also had the advantage (many would query this) of diving with a buddy (i.e. me) who dives on twins and could help him at each step

Do we "dive deep"?
Depends on how you define "deep"
Most of our dives are off the East Coast in the 30-35m range (on Nitrox), so we get optimal use of twins

Matt-75

15-05-2006, 14:40

As it goes so far, i have a Tekwing, with twinning bands (currently configured for single cylinder). Its what i use for pool training and general diving (and for use abroad). I got it so that this upgrade option was available should i decide to go for it. Likewise with the reg set. The second set can be altered to support either my pony or the second 10L for my twins (although it would be better eventually to just get something dedicated for the pony, but i dont see much need for that at present until advanced nitrox when i might use the pony with a rich mix for my safety stop).

The nitrox course will be booked soon (within 3 weeks).

Do i want it to dive deep, well deep for me would be 30m (i would probably be diving more around the 20-25m level for the most part), and with a twin i could stay down for a little longer. If it was a club dive i would probably still use the single 12 with pony, because no one dives twins in my club. So i guess the twins arent for club dives, but for other times when i dive with others (like my PADI friends in south wales, some who dive twins).

Would love advice on trim and weighting with regards twins, but i think its something i'll have to play with in the pool. I would think i could carry a little less lead since i have an extra 10kg of weight on my back.

Finding buddies, up here who dive twins, well i guess YD would be a good place to start posting, or one of the dive site websites. Most of the people in the club dont even have ponys, and dive on single 12s, relying on the fact that their buddy will have adequate air to bail them both out of whatever situation they put themselves in. Not an ideal way to approach it, but i guess it works most of the time.

Adrian Kelland

15-05-2006, 14:55

Finding buddies, up here who dive twins, well i guess YD would be a good place to start posting, or one of the dive site websites. Most of the people in the club dont even have ponys, and dive on single 12s, relying on the fact that their buddy will have adequate air to bail them both out of whatever situation they put themselves in. Not an ideal way to approach it, but i guess it works most of the time.
There is nothing particulary right or wrong in that. One training organisation teaches it. However it is calculated and part of the plan. Just because you have a pony or even twins it does not means you have enough gas when it most matters.

Matt-75

15-05-2006, 15:07

There is nothing particulary right or wrong in that. One training organisation teaches it. However it is calculated and part of the plan. Just because you have a pony or even twins it does not means you have enough gas when it most matters.

I agree.

But their may be times when you cant just bailout 2 people on a 12L. Having an extra 3L for one person improves the odds that you get out of the situation without a pot visit or soiled underwear.

I also view it on the grounds that if i run low on air, or something catastrophic happens like a 1st stage failure i can just switch onto my backup for bailout, without using my buddies air.

I guess as you say their is no 100% yes or no answer to the question. Views differ.