Is this a good deal/choice for a set of doubles?

[CuzzA]

I'm going to look at them today. I can't tell what they are rated for. Maybe someone can tell from a picture.

 

[Caveeagle]

You can't tell without looking closely at the stamps. It's worth noting that these are not a matched set. So you can see the difference in the neck transition. As long as they are the same spec/dimension, it is not really an issue, but you should be aware that you need to look closely at the markings on both tanks.

Since they are marked for Nitrox, I would hope the insides are clean and well maintained. (trust but verify).

a) You can't really go wrong at $150, so unless that's your last $150... its probably a good buy
b) Just make sure they are not the 1800psi rated versions and they don't have the vinyl inside coating. (not likely IMHO)
c) I would take a look under the boots, jus to make sure they are not rusty.

Nice set of inexpensive doubles for a ~100' nitrox dive and to get you used to diving BM/doubles. They would still not be my first choice for a Deep/Tri-mix dive.

 

[tbone1004]

ok, so they aren't a matched set. Kind of annoying, but for $150, the manifold and bands are worth it. LP72's make brilliant everything bottles and I love my set of double 72's. They're simply amazing.

At $150, the bands and manifold can be used on LP85's, AL80's, HP100's, anything like that, and the manifold can be used on your 112's if you need that much gas, so for $150, I'd grab them, especially if they are in hydro. I'd question where the bolts and hardware are for the bands though....

 

[rhwestfall]

I'd be cautious.... why are they sitting like that (Unbolted/partially assembled)? Moving them could have screwed up the manifold.

 

[CuzzA]

Thanks for replying guys. Good catch on the tanks not matching. I didn't notice in the pic.

Now I'm unsure what to do. Lol

So far I've been good about buying dive gear I actually use and not making the mistake of buying something only to have it sit.

These would be for the ART class which is what, 165' and then future dives in that range, but that leaves me short of 1 cu ft per foot at depth assuming these can't be jacked up a little bit.

Assuming something is wrong with the manifold (obviously I would check), Given a new hydro and VIP I think $75 per tank is still a good deal, but would I use them if they weren't doubled or is there simply better options? I read they make great O2 bottles due to the fill pressures.

 

[tbone1004]

they can be hiked up. If they still have their + rating which the hydro shops will test for if you ask, they are good to easily fill to 3000psi which gives them an 87cf capacity.

They make great O2 bottles, but they can be heavy in the water compared to an AL80 so it's not a bottle I like to carry with me on a dive. They only hold about 10% more than an AL80 at the same fill pressures, so it's not a huge benefit.

I personally will use double 72's before I ever dive big single tanks, especially when teaching. You get redundancy and better balance without sacrificing gas volume. Yes it is an extra tank to maintain, but for recreational diving I much prefer small doubles. This set will be about 30lbs lighter than a set of double 112's when empty, ~60lbs vs 90lbs, and close to 40lbs lighter when full *~75lbs vs ~115lbs*, and give you about half the gas. This is assuming the LP72's getting filled to ~2800psi vs the 112's filled to 3600psi which is the norm in cave country.

Like I said above, as long as the manifold is OK *cross bar turns freely*, then $150 is a good deal. You can always buy a set of bands from the guys breaking doubles down for sidemount and double up your 112's using that manifold and then sell the 72's with the 112 valves for $50-$100 each and at least get your money back if you decide you don't like them after class.

Other nice thing about these for your ART class is they are going to save you a bunch of money on helium since they're small tanks and you don't have to fill the big ones all the way up for class

 

[CuzzA]

cross bar turns freely

Can you elaborate more on this. Are you saying the crossbar should rotate freely.

 

[tbone1004]

if you loosen the two nuts that are on the end of the crossbar, it should rotate freely. If it doesn't, then it was damaged because the bands are left loose. Unlikely, but possible

 

[Stoo]

If they are galvaniized tanks, grab them. If not, satisfy yourself that they are free of rust. They aren't large tanks and depending on their ratings and age, you may not want to overfill them, so as long as you aren't a gas-hog, then they're likely great. Pay particular attention to the area under the boots if they have them (and then ditch the boot if you can).

I dive doubles exclusively at home. I have twin LP80s, LP95s and HP130s. I can tell you that I use the 80s 98% of the time, simply because they're lighter and entirely suitable for most of the diving I do.

 

[Stoo]

OK, just looked at the picture... is there an isolator in the middle of the manifold? It looks like there is, but it's turned to face backwards, which is odd, and suggests the manifold is lose...

If it's not an isolator, then their value is greatly diminished. In fact they likely won't make "spec" for your course. The main benefit of doubles is to be able to separate the two tanks.