Turning singles to twin

[Cussy]

Enough of my flippancy (oh yes, did I mention I'm divorced, so it's wasn't great advice).

There is another option:

Why manifold? Why not have two independent cylinders, that way all you need is the bands or something like the buddy twin-cambands. I know a few divers that have said manifolding wasn't necessary (I know this is going to get a lot of comment!!!) - some have suggested two independent cylinders with different air mixes. You could save a lot this way. That would make upgrade from a single to a twin a lot easier and you can then also have a flexible system so that you don't look a prat doing a shallow bimble on twins - just use one of them.
Rob

[incapete]

That's the route I'm going down - much easier to get started and I like the flexibility of the setup.

P

Originally Posted by Cussy

Enough of my flippancy (oh yes, did I mention I'm divorced, so it's wasn't great advice).

There is another option:

Why manifold? Why not have two independent cylinders, that way all you need is the bands or something like the buddy twin-cambands. I know a few divers that have said manifolding wasn't necessary (I know this is going to get a lot of comment!!!) - some have suggested two independent cylinders with different air mixes. You could save a lot this way. That would make upgrade from a single to a twin a lot easier and you can then also have a flexible system so that you don't look a prat doing a shallow bimble on twins - just use one of them.
Rob

[AlanP]

Well if I buy 2 singles and they come with valves, how hard would it be to chop and change? Could I dissemble the twin to make up x2 singles and put the manifold and bands to twin up?

Does any one do this, or do they buy some singles then buy a twin as well?

[Hickdive]

Originally Posted by AlanP

Well if I buy 2 singles and they come with valves, how hard would it be to chop and change? Could I dissemble the twin to make up x2 singles and put the manifold and bands to twin up?

Does any one do this, or do they buy some singles then buy a twin as well?

If you buy a twinset from say Go-Dive, it will actually be delivered as two singles that just need to be filled to be used as singles. To convert to twins you need to remove the blanking plugs from the cylinder valves (having made sure the cylinders are empty first ) screw in the manifold and attach the bands, all of which will have been sent loose. It's only a few minutes work, especially as you get practiced. Woz did an excellent guide, try searching YD for "Assembling a twinset"

[scuba g]

Originally Posted by Scuttler

OK....people will tell you that you have to have the same size cylinders or they'll twist the manifold etc.

Lobbocks.

Your bands should be good quality and matched to the manifold (I use AGIR bands as they are the widest and as good as the Highland Mills which I believe are no longer made).

Once your bands are on these are what are holding your cylinders in place.

If your bands are cheap and cheerful then yes there is the possibility of movement but it's remote.

When you shift your cylinders around you'll never get both cylinders grounding at the same time so saying your stressing the manifold by having different height cylinders also applies to having cylinders that are the same height....unless you've calibrated arms so that they lower the cylinders perfectly every time.

Putting twins together, best to have them lying flat on a bench, attach the manifold and have the bands sitting losely around the cylinders, once you have torqued the valves, then start tightening the bands, this way you have light or no pressure on the manifold, plus, if the tanks are slightly off height wise, the tension isnt on the valves, the bands once tightened will take the majority of the strain. With 12's, you may find between Lux or Faber around 4/5mm off, with boots on, this is hard to notice.

[Scuttler]

Originally Posted by scuba g

Putting twins together, best to have them lying flat on a bench, attach the manifold and have the bands sitting losely around the cylinders, once you have torqued the valves, then start tightening the bands, this way you have light or no pressure on the manifold, plus, if the tanks are slightly off height wise, the tension isnt on the valves, the bands once tightened will take the majority of the strain. With 12's, you may find between Lux or Faber around 4/5mm off, with boots on, this is hard to notice.

Agreed.

I've two Heisers differ by about that much.

[RogerViking]

buy the cyls togeather at least that way there are compatable for testing purpose.. you dont want to have a fill refused cause one of your bottles is out of test or O2 unclean.

better to buy the manifold, valves, bands, and bottles togeather im my o/p.

roger

[Scuttler]

Originally Posted by RogerViking

buy the cyls togeather at least that way there are compatable for testing purpose.. you dont want to have a fill refused cause one of your bottles is out of test or O2 unclean.

Not totally in agreement with you here. Whilst what you're saying makes perfect financial sense. After the the first test both cylinders will be in synch.

[David G]

Originally Posted by Hickdive

If you buy a twinset from say Go-Dive, it will actually be delivered as two singles that just need to be filled to be used as singles. To convert to twins you need to remove the blanking plugs from the cylinder valves (having made sure the cylinders are empty first ) screw in the manifold and attach the bands, all of which will have been sent loose. It's only a few minutes work, especially as you get practiced. Woz did an excellent guide, try searching YD for "Assembling a twinset"

Ummm, well this is an admission that I just spent money at GD , but although the twinset came disassembled there were no blanking plugs so it would not have been possible to run them as singles.

Cheers,

David.

[G man]

Originally Posted by Scuttler

OK....people will tell you that you have to have the same size cylinders or they'll twist the manifold etc.

Lobbocks.
Your bands should be good quality and matched to the manifold (I use AGIR bands as they are the widest and as good as the Highland Mills which I believe are no longer made).

Once your bands are on these are what are holding your cylinders in place.

If your bands are cheap and cheerful then yes there is the possibility of movement but it's remote.

When you shift your cylinders around you'll never get both cylinders grounding at the same time so saying your stressing the manifold by having different height cylinders also applies to having cylinders that are the same height....unless you've calibrated arms so that they lower the cylinders perfectly every time.

Dont be a donut, what if Alan purchased a faber and then a heavy Euro cylinder in the future, that would make a great twinset wouldnt it.

get a matching pair of cylinders at the start.

G.