Vintage Tank Bands

[KY_BOB]

You should see the shop, old gear everywhere. You going back to Bonaire next year Bob?

I would like to but I also like seeing new places. I have a trip planned to Cozumel in January but a late summer trip might be possible.

As you know, I'm a fairly new diver. To me, one of the more interesting possible dive locations that I would like to see is in your back yard. As sweet as the wildlife and coral was in Bonaire, I would like to get a little tech training and gear and check out some of the Atlantic wrecks.

I will go back to Bonaire but it, most likely, be after another location or two. I would love to dive with you sometime. Anyone that wants to do something a little different, be it dive vintage gear or something a little on the tech side, is my kind of buddy.

 

[duckbill]

Paladin,

The way to know if the spacing it dead on is to attach the bar to your tanks. With the tanks as parallel as possible, measure the center-to-center spacing of the cylinders at the necks. If the center-to-center spacing of the bands is the same, or very close, then they are good.

If the spacing is perfect or slightly tight, I promise you will need to leave your bands a little loose to get the bar on the valves. It would be physically impossible to get the convex rings at the ends of the bar into the recesses of both cylinder valves if the tanks cannot move apart.

If the bands set the tanks slightly apart, you will need to tighten the yokes on the bar before tightening the bands, as it is not likely that the yokes on the bar will be able to pull the valves together if the bands are tight.

Tighten the bar on the valves, then tighten the lower band, and make the upper band snug, but not too tight. That way, you will get the best seals. Just be sure not to use bands that are too wide or too narrow, as that will put unwanted stress on the system.

For the first time you get them together, you would be advised to put a regulator on the yoke, pressurize the system, and immerse the bar and valves while trying to twist and turn the cylinders to see if any leaks develop.

Then, go have fun.

 

[Gilldiver]

Thanks again. The bands are covered with vinyl but the coating is damaged in a few places. The steel underneath is slightly rusted at the points where the vinyl is torn. Now that I know that they are usable, I intend to strip the vinyl off, use a good rust remover/inhibitor, then coat the bands with epoxy and paint them.

Divers Supply sells a plastic backpack that has attach points that look as if they are meant for just the type of bands I have. I'll get one of those when the bands are ready to use. The backpack on my 72 also has them, but I like to have a separate backpack for each of my tanks. I have one on my 72 and one on my AL80. Both are vintage backpacks with rubber insulated metal cam bands.

I used a DiveRite classic wing (it wasn't a "classic" back then) with those bands and a plastic back pack between about 1989 and 1996 or so. I put a bolt hole in the wing to match the spacing of the back pack with a gromet kit from Home Depot. The back pack was bolted on with a short bolt and wing nut. I still have a bunch of those bolts and nuts as I always had an extra set or 2 for when switching tanks on small rocking boats off of the Northeast. You end up droping a bolt every now and then over the side or into the bilge.

Here is a back pack on the Bay. Just get rid of the tank strap, put in a lower bolt hole in just about any horse shoe style wing and you are good to go.
Scuba Diving Dive Tank Adjustable Back Pack with Strap - eBay (item 220471437209 end time Sep-24-09 14:47:58 PDT)

 

[Paladin]

I finally got my twin set put together. I used two steel 72s: One is my old 1976 Healthways and the other is a 1968 Walter Kidde. The WK is about 1/4" shorter than the Healthways, so I compensated by using a longer valve on it. With the short Sherwood valve on the Healthways and the longer USD valve on the WK it works out perfectly. I picked up another set of bowed bands off Ebay that are made of wide stainless steel with rubber sheaths around the bands to protect the tanks from scratches. The Dacor adapter is just the right length to use with them, too.

I stripped that old, ugly burnt orange-yellow paint off the WK and painted it light yellow to match the Healthways. After mounting the bands on a plastic backpack (it already had hardpoints molded into the plastic) with stainless steel bolts and wide washers, I slipped the assembly over the tanks. Even with the bands loose, the spacing was perfect for the cheater bar and the tanks had to be pulled apart slightly to fit it on. I tightened the cheater bar to the valves then tightened down the bands, tightening the bottom bands first. Next came the upper bands. Once everything was tight, I popped a regulator onto the center tap and turned on the gas from both tanks. No leaks. I put it in a tub full of water and tried working the whole thing around to test for play or leaks. The whole unit is completely immovable. No matter what I did, everything held tight without so much as a burp.

Now only if summer would hurry up and get here!

PS to Duckbill:
I followed your valuable advice and it all went together without a hitch. Thanks!

 

[John C. Ratliff]

I've used the manifold connector ("suicide bar") for years with good success. I had a set of twin 40s set up that way until I had to have them drilled. Thy were converted life raft bottles, and when the USAF began condeming their jump tanks (the same type of tank) I got rid of mine. The 1/2 inch pipe threads had to be cut into the neck of the life raft bottles (20 man life raft, CO2 bottles). I had them connected with this "twin tank bar yolk," as USD used to call it, for years. Here is what they looked like.

I like the way Duckbill described the method of converting the single 72s to twins using this setup. It is what I used too. One other way of making the two tanks with slightly different lengths correct is to used different tank boots to equalize the two lengths. But I like the valve method Paladin954 used too. One method I have used is to connect the tanks with the tanks laying on their sides. I then put the bands on loose, connect the valves with the bar yolk, and screw it down fairly tight. That puts the tank's valve openings at the 90 degree angle ideal for making a good seal. I then put the bands on, tightening the lower one like Nemrod stated, then the upper one. However, I don't like a backpack, and so have bands that accept the military-style harness without the backpack. The upper band I place as high on the cylinders as I can get it and keep hold, and the lower one about 12 or so inches below.

SeaRat

PS--I still miss those small doubles.

 

[duckbill]

I'm glad you got her set up. Now the fun starts when you go to get fills! Keep us posted on all the comments you get

BTW, it's O.K. if the tanks are different lengths, as long as you get the tanks and bar tightened up all nice and square first. The set will just sit cockeyed when leaned up against the wall, but it won't hurt anything. It would be really fun to hear fill jockeys' remarks if you paired a 72 with a 38. Tell them you want oxygen in one and nitrogen in the other:laughing:

 

[WD8CDH]

I used to dive a USD aluminum 72 paired with a USD aluminum 50 with a battery canister light below the 50. Sometimes the tank monkey wouldn't fill it because they thought half of the air would go in the smaller tank and it would blow up.

 

[duckbill]

...they thought half of the air would go in the smaller tank and it would blow up.

That's too funny!:lol:
Summer help can really tick us off sometimes, but is often worth a lot of good laughs in retrospect

 

[Paladin]

The owner of the dive shop I go to loves to give me a hard time over my gear preferences, but it is all just good natured ribbing. He is older than I am and used to use the same stuff years ago. In rare moments of candor, he agrees with my choices for the same reason I have for choosing them. But I am sure he is gonna have a field day teasing me about my twin setup!

Recently, he asked me to bring my stuff down to his shop and get into the pool with one of his classes. I used a single 72 with J valve, my DA Aqua-Master, one five pound weight, a watch and a capillary depth gauge. No BC and no SPG. After a short talk on the beginnings of SCUBA and how a diver can safely dive with minimum gear, I was given strict instructions to not resurface for any reason until, by calculating my air consumption by watch alone (but before my J valve started honking), I figured myself to be at about 500 PSI.

We all got into the water and I knelt in the deep end (12') of the pool and watched the class up in the shallow end until they all came down to join me. The class went through air sharing drills using their octopuses. When they were done, my friend came over to me and gave me the out of air signal. We then buddy breathed for five minutes using my Aqua-Master. Then he returned to his class and began buddy breathing with them until they all could do it flawlessly.

Near the end of the pool time, he signaled for me to take my tank off. I pulled it over my head and placed it on the bottom. Doing the old "blow and go," I went to the surface, grabbed a lungful of air and shot back down to put my tank back on.

When I figured I had about 500 PSI left in the tank, I headed for the shallow end. My J valved hadn't started honking yet (which it does at 500 PSI) but I knew it wouldn't be long. I climbed out of the water and set my rig aside to wait for the rest to get finished with the class.

When they were done and everyone was out of the pool, my friend put his Titan on my tank and opened the valve. The gauge read about 550 PSI. He held it out for his students to see. He then gave a little talk about how all the new technologies make it easier to learn to dive but that the new devices should be viewed as conveniences and not used as crutches in place of skill. He then offered to teach the old skills, free of charge, to anyone interested in learning them. Five of the six students expressed an interest in the extra training. The lone holdout was a kid of 18 or 19 who was an obvious tech junkie. When the class was over, the tech junkie grabbed his stuff and left. The other five attacked me with a barrage of questions about my gear and how I use it. One even asked me where she (yes, she) could get a DH reg. She liked the idea of having the exhaust bubbles behind her instead of roaring passed her face.

I got a free fill out of the deal and had a good time to boot.

 

[Slonda828]

The owner of the dive shop I go to loves to give me a hard time over my gear preferences, but it is all just good natured ribbing. He is older than I am and used to use the same stuff years ago. In rare moments of candor, he agrees with my choices for the same reason I have for choosing them. But I am sure he is gonna have a field day teasing me about my twin setup!

Recently, he asked me to bring my stuff down to his shop and get into the pool with one of his classes. I used a single 72 with J valve, my DA Aqua-Master, one five pound weight, a watch and a capillary depth gauge. No BC and no SPG. After a short talk on the beginnings of SCUBA and how a diver can safely dive with minimum gear, I was given strict instructions to not resurface for any reason until, by calculating my air consumption by watch alone (but before my J valve started honking), I figured myself to be at about 500 PSI.

We all got into the water and I knelt in the deep end (12') of the pool and watched the class up in the shallow end until they all came down to join me. The class went through air sharing drills using their octopuses. When they were done, my friend came over to me and gave me the out of air signal. We then buddy breathed for five minutes using my Aqua-Master. Then he returned to his class and began buddy breathing with them until they all could do it flawlessly.

Near the end of the pool time, he signaled for me to take my tank off. I pulled it over my head and placed it on the bottom. Doing the old "blow and go," I went to the surface, grabbed a lungful of air and shot back down to put my tank back on.

When I figured I had about 500 PSI left in the tank, I headed for the shallow end. My J valved hadn't started honking yet (which it does at 500 PSI) but I knew it wouldn't be long. I climbed out of the water and set my rig aside to wait for the rest to get finished with the class.

When they were done and everyone was out of the pool, my friend put his Titan on my tank and opened the valve. The gauge read about 550 PSI. He held it out for his students to see. He then gave a little talk about how all the new technologies make it easier to learn to dive but that the new devices should be viewed as conveniences and not used as crutches in place of skill. He then offered to teach the old skills, free of charge, to anyone interested in learning them. Five of the six students expressed an interest in the extra training. The lone holdout was a kid of 18 or 19 who was an obvious tech junkie. When the class was over, the tech junkie grabbed his stuff and left. The other five attacked me with a barrage of questions about my gear and how I use it. One even asked me where she (yes, she) could get a DH reg. She liked the idea of having the exhaust bubbles behind her instead of roaring passed her face.

I got a free fill out of the deal and had a good time to boot.

You, in my humble opinion, just summarized why vintage diving is a critical part of the sport of diving. The fact that skills can replace gear (and NOT the other way around), and that you can still dive safely within the limits of your training and experience are why I love diving old gear. You also took the time to show new divers where the sport came from, and that is an important part of our history that we cannot afford to lose when the older divers retire. Thanks man.