Squidlips
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First Name: Ken
Location: Boston MA

Need advice: twin 1800's

Sun Feb 19, 2017 3:35 pm

Hello,

I have the opportunity to buy (or not to buy) a set of vintage 1800 psi twins but have zero experience with any twin set ups let alone vintage twins.
so I am looking for some advice/guidance if I should or should not go for it.

The tanks:
Steel US Navy 1800's from 1952, last hydro 1979, rusty exterior, stored with air. Complete with backpack and valve
also:
Steel Sportsways 1880's from 1964, last hydro '69, clean galvanized, stored with air. Complete with backpack and valve.

The prices are fair but I can only afford one.
Are either of these worth getting into?

Any advice will be greatly appreciated.

Squidlips

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Herman
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Location: Raleigh NC

Re: Need advice: twin 1800's

Sun Feb 19, 2017 4:34 pm

Either should be OK. I think if I were looking at them, I would likely go for the galvanized ones unless you intend to paint them some color then I could go with the best back pack and/or manifold. I would try to get the seller to agree to return them if they are not OK inside (excessive rust) or it they will not pass hydro unless they are real cheap....then I would get both sets.
Herman

Squidlips
Diver
Posts: 18
Joined: Fri Mar 01, 2013 9:26 pm
First Name: Ken
Location: Boston MA

Re: Need advice: twin 1800's

Sun Feb 19, 2017 7:08 pm

The galvanized tanks look unused and the manifold is in great shape. Judging by the hydro dates it almost seems like they were barely used.
The Navy tanks are beat and the manifold looks more than used. I like the 'beat up' look, so long as they function, and have no plans to ever paint
scuba tanks.

That being said, the seller won't take them back if they fail hydro but he did lower the price to the point where I could buy both.

At the end of the conversation he said: "by the way....I've got a set of twin 72's that I might be willing to part with."
I didn't see them but he said they too were from the 50's and last hydro tested in 79. The price was too high in my opinion, though I would
like to put together a set of 72 twins someday. I have been diving single 72's for 30 years and am finally considering it, but since I'm strictly a shore diver
I'm not sure I'm up for lugging twin 72's around. The weight in the water is no problem and in fact I welcome it. Anything that gets me to shed weight
off the belt is a good thing.

kworkman
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First Name: Keith
Location: Columbus, OH

Re: Need advice: twin 1800's

Mon Feb 20, 2017 12:32 am

Are the cylinders half inch valves, 3/4 or 1/2" with bushing?

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captain
Plank Owner
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Location: LaPlace, LA

Re: Need advice: twin 1800's

Mon Feb 20, 2017 11:19 am

The Navy cylinders are probably re-purposed CO2 raft inflation cylinders and use a reducing bushing. I would stay away from them as they present a additional problem when hydroing them and most if not all shops (wrongly) think the reducing bushing are illegal and will not fill them. If you have a compressor or willing to deal with the hassle of trans-filling them from other tanks then go for them.
Captain

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ScubaLawyer
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Re: Need advice: twin 1800's

Mon Feb 20, 2017 4:43 pm

Agree with Captain. While possessing a mighty cool-factor, the older Navy's might be more of a problem in the long run. I really like the Sportsways twin 38s and have a set i'm refurbishing. My 2psi.
"The diver who collects specimens of underwater life has fun and becomes a keen underwater observer. .. seek slow-moving or attached organisms such as corals, starfish, or shelled creatures." (Golden Guide to Scuba Diving, 1968) :D

Squidlips
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Joined: Fri Mar 01, 2013 9:26 pm
First Name: Ken
Location: Boston MA

Re: Need advice: twin 1800's

Mon Feb 20, 2017 6:36 pm

The Navy tanks have reducers, the Sportsways do not. Even though I could take both I'm not set up to do my own fills nor do I want to bounce from shop to shop looking for someone who will.

I'm going to take the Sportsways and see how it goes. I'm not expecting them to be dive-ready so this will be a new challenge for me.

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SurfLung
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Re: Need advice: twin 1800's

Mon Feb 27, 2017 2:51 pm

- I have both sets and can offer my opinion of each:

Sportsways Pros - The manifold system is superior to the USD system because of the fool proof O-ring seals between the center valve and the two tank valves. The twin tanks ride perfectly on my back and position my double hose regulator perfectly too.
Sportsways Cons - Because they are 1880 psi, they have more steel and are heavier. I wear 2-4 lbs of weight with these tanks and a 3 mm wetsuit for neutral buoyancy at 20 feet. At 50 ft I wear no weight belt with these tanks and 3mm wet suit.

USN 38s Pros - Being 1800 psi and therefore less steel, these are lighter than the Sportsways to carry and more buoyant underwater. I wear 10-12 lbs weight belt with a 3mm suit at depths to 20 feet. At 50 feet and deeper I wear 6 lbs weight belt with a 3mm suit. I can even dive these tanks with just a swimming suit and I don't sink due to excess tank weight.. The twin tanks ride perfectly on my back and position my double hose regulator perfectly too.
USN 38s Cons - None. For me anyway. I enjoyed restoring the tanks and they have become my favorite tanks to dive with. I refill them easily from other tanks. These and a set of yellow USD Twin 38s (also 1800 psi) have identical buoyancy characteristics and they are a close 2nd in my favorites column.
Image
Above left: USN 38s. Center: USD 38s. Right: Sportsways 42s

Interesting Side Note: The Sportways tanks are 38 cf at 1880 psi but they were advertised at the 10% overfill capacity and referred to as "42s". The USD tanks are 38cf at 1800 psi and were originally advertisaed as "38s". The USD ads were later changed to the 10% overfill capacity so they could call them "42s" ... to compete with Sportways I assume.
SurfLung
The Freedom and Simplicity of Vintage Equipment and
Vintage Diving Technique are Why I Got Back Into Diving.

Squidlips
Diver
Posts: 18
Joined: Fri Mar 01, 2013 9:26 pm
First Name: Ken
Location: Boston MA

Re: Need advice: twin 1800's

Mon Feb 27, 2017 10:01 pm

Cash in hand.....he backed out of the deal.
Not a man of his word. Glad I didn't give him my money.

That being said,I really appreciate all the input and I'm greatful that this community
exists.

SurfLung...I have followed your twin tank thread with interest and because of it I became interested in small twins. The information you posted here is helpful too. It's the little things that make a big difference. I feel a bit more educated and I thank you for taking the time to post a reply.

The search continues!

My best,
Squidlips

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