aluminium dual system

[KP3S]

This might have been ask before but I did a search and it came back with lots of pages but I could not find what I was looking for.

Any one knows where if there is one, to get a kit to make 2 aluminum 80cf into a dual system? I know I need a manifold, and the band kit but so far I have found kits for steel tanks. I am a disable diver and I do not think I can carry 2 100cf steel on my back.

On top of that I already have 2 Luxfer 80cf and living on SSI makes it tough to have to buy 2 steel tanks, I want to dive a bit longer that 1 hours with 1 80cf, a friend told me to get a bigger aluminum tank but the price of shipping for these big boys and the cost is out of my budget, I live in Puerto Rico and shipping is a killer here. Maybe if I look around I could find them used but I do not trust used equipment with my life and my wifes agrees with me. Any help would be appreciated, thanks for ready this post.

 

[ding dang]

yes - there are several choices. remember that double AL80's will be very buoyant, so it's fortunate that you live in PR!

in order to run the usual setup of double tanks on your back, you'll need a generic backplate/wings setup with a harness. unless you can think of some way to mount doubles on a regular jacket-style BC, you'll be out of luck. it probably wouldn't be very safe, anyhow.

so, the BC can be purchased online for cheap from divegearexpress.com, or scubatoys.com - a basic harness is $26, a stainless steel plate is $75 (so you won't have to wear as much lead), and you can find a nice 30-40lb wing used on ebay for much cheaper than if you were to buy it new. the wings can get quite expensive; fortunately, you're not using steel, aluminum is buoyant, and your rig will be relatively easy to float, so you won't need a massive wing. check me on that though, best to buy wings only after calculating your rig. you can find that on here easily by searching.

once you have your BC all set, you can begin your search for doubles. scubatoys has a great package deal with tanks, bands, and valve for $550. if you already have the matching tanks you want to use, all you need is a valve (200 or 300 bar, depending on if you'll be using primarily DIN or yolk regulators), and the bands. AL80's are usually 7.3-7.5 in diameter, but check with your manufacturer. it doesn't matter if it says they're for steel tanks - all that matters is that the circumference of the bands match those of your tanks you want to double up.

after that's all said and done, make sure you take it to be built at your LDS, as new tanks will require a VIS, and your old tanks will require a VIS after removing the valve to put on the double manifold.

also, you'll need another primary regulator. you'll mount one primary on one manifold post with your regular secondary stage, and then another primary on the opposing post, with your octo second stage on that, and your SPG and BC hoses on opposing posts as well.

it's expensive, but bottom time is nice. if you don't want to go through all that, you could just sling another 80 off to your side and switch when you get low. money saver, but not as safe.

good luck!

 

[KP3S]

Thanks for the advice, I will study all my options and then I will make a plan to buy all the required equipment. Who knows maybe I will go for a rebreather and I think it will be lighter on my back and on my pocket on the long run, Thanks again.

 

[parzdiver]

Check out Welcome to PRTDC. They should have the equipment and be able to provide the instruction necessary for doubles. While I don't have personal experience with them, they are affiliated with my LDS in Pennsylvania and come highly recommended to me.

 

[knowone]

What sort of diving will you be doing. Will your wife agree to using a hookah.

 

[KP3S]

I do not like the Hookah, I tried but is not for me. I usually dive the same reef since is only 10 miles from home but I would like to dive longer @ 50-100 feet tops. I enjoy scuba but I am not into deep diving. I already have a complete set of scuba gear with 2 Luxfer 80Al, 19cf pony bottle (I dive Solo, most of the time), BCD, dive computer, lights/torches, 2 dive buoy's, sea scooter plus some other gear, like spare fins, mask, snorkel, octo + reg. that I carry on my back up dive box in my 1992 Pathfinder and my regular diving gear, tools, spare o-rings, hoses. The only thing I would like to have a small personal compressor for when I decide to go to a remote beach and camp out all week end and do not want to go every time I use my 2 tanks to a dive shop to get them fill and a back up BCD.

I live on the west side of the island and I am planning next month a dive trip to the East side ( 100 mile trip )from Friday to Monday to do nothing but diving day/night, BBQ'ing and relax with my wife and out 5 female Chihuahuas. I have heard that is a beautiful area for diving.

 

[gearhound]

HP steel 100s are not that much heavier than aluminum 80s, but they are more negative in the water (meaning less weight on a weight belt). Have you considered sidemount? You can use your existing tanks and still have them available for when you want to dive singles. No bands or manifold to buy. It's easier to carry singles to the water also. Have a look at www.gosidemount.com. Most of his dives and videos are in caves, but he does have one video where he is diving an ocean wreck. There are commercially available sidemount harnesses from Dive Rite, Hollis and Golem Gear. Or you can buy the Razor from Steve.

 

[DaleC]

I agree with gearhound about the weight factor. I dive double Al 80's and double St 72's and I have to add 10lb's of lead to dive the 80's.
Among other options look into St 72's. They are small, light and only hold 5cuft less gas than an Al 80. A little looking around will usually come up with used tanks and bands for cheap.
Another option for you may be independant doubles. a search on the board for independant doubles will bring up lots of info. Here's a link to a thread that shows what's involved in my set up: http://www.scubaboard.com/forums/technical-diving-specialties/334251-independent-doubles-hose-routing-secondary-position.html