Advice on New vs Used Tanks

[Collin O'Brien]

Or, how pristine the tanks are. I have a few HP 80s (PST) and HP 100s (PST) that are showroom new looking, inside and out. Some need hydro and others have fresh hydros. I would ask stupid high prices for them. They are too good to give away.



Bob knows his stuff. He is also very common sense oriented. He has seen it all before. A new AL80 is hard to beat. A new AL100 is much more expensive and somewhat available. For your first tank, a new AL tank is probably the best choice.

cheers,
m

With a S100, SS BP and 7mm wetsuit in New England I am basically perfectly weighted (maybe add 2lbs max). I think I needed 10lbs with an AL in Florida if I remember correctly. I'm also 6'3 very athletic build so apparently I use air a little more air than other divers so any extra air I can get, I'll take (this is just how it was explained to me). This is why I have been looking for a S100, do you think AL is still a better option?

 

[Tracy]

With a S100, SS BP and 7mm wetsuit in New England I am basically perfectly weighted (maybe add 2lbs max). I think I needed 10lbs with an AL in Florida if I remember correctly. I'm also 6'3 very athletic build so apparently I use air a little more air than other divers so any extra air I can get, I'll take (this is just how it was explained to me). This is why I have been looking for a S100, do you think AL is still a better option?

For single tank diving, Aluminum is almost never a better option.

 

[Marie13]

Cold water diving with a thick wetsuit and an aluminum tank? Nope. Steel is the better choice.

 

[tbone1004]

With a S100, SS BP and 7mm wetsuit in New England I am basically perfectly weighted (maybe add 2lbs max). I think I needed 10lbs with an AL in Florida if I remember correctly. I'm also 6'3 very athletic build so apparently I use air a little more air than other divers so any extra air I can get, I'll take (this is just how it was explained to me). This is why I have been looking for a S100, do you think AL is still a better option?

aluminum is not the right answer for single tank diving, basically ever due to it being very inefficient in terms of cf/lb. High pressure steels are always the right answer. Aluminum is so prevalent in the caribbean because the bottles are cheap and you can abuse them a lot more than with steel.

Whomever explained your air consumption issues is not necessarily correct. I'm your size and when I'm doing calm reef dives my sac rate is about .45. It does jump to .65 when I'm working underwater, but even that is considered "normal" and I am almost never the one turning the dive. If you have a high SAC rate, it is likely due to excessive and inefficient motion and/or poor breathing techniques.
More important to this though is that if you were cave diving you would be given the smallest tanks because your reserve is being held in the other peoples tanks. If you run out of gas or have a failure of some sort, you need to make sure that your buddy is calculating rock bottom reserves with your SAC rate in mind or you both may not make it to the surface

 

[halocline]

aluminum is not the right answer for single tank diving, basically ever due to it being very inefficient in terms of cf/lb.

That depends. Cold water, yes. Warm water with a thin or no wetsuit? Not necessarily. Some divers, myself included, sink like a stone in steel tanks with a thin wetsuit. Al80 (or 63, even better) are fine for things like shallow reef dives in the tropics.

That said, the AL100 is a horrible tank for almost anyone due to it's size, weight, and buoyancy. So for big tanks, yes, steel is way better.

 

[tbone1004]

That depends. Cold water, yes. Warm water with a thin or no wetsuit? Not necessarily. Some divers, myself included, sink like a stone in steel tanks with a thin wetsuit. Al80 (or 63, even better) are fine for things like shallow reef dives in the tropics.

That said, the AL100 is a horrible tank for almost anyone due to it's size, weight, and buoyancy. So for big tanks, yes, steel is way better.

That's why I said basically ever
I'm the same, I can bare tank breathe on an empty al80 at the bottom of the pool in a bathing suit without issue, my brother is even worse. I was diving this past weekend with a 3mm full suit, my freedom plate, and a LP121. With 1500psi in the tank, my 30lb wing had the OPV going and I still had to skull a bit to stay at the surface. It's not a dangerous configuration though since I can still kick the whole rig to the surface if I had to, but most people don't sink like bricks.
AL100's are about the same buoyancy wise as the steel tanks but weigh like 10lbs more than a HP100 steel, and are about the same size/weight as a HP130, it's stupid.

 

[Collin O'Brien]

I don't believe there is any difference in that series, I think the hot dip galvanized is called F7 or F8 but am not 100% sure. If you have pictures of the tanks then I can tell you which series.

I just

That's why I said basically ever
I'm the same, I can bare tank breathe on an empty al80 at the bottom of the pool in a bathing suit without issue, my brother is even worse. I was diving this past weekend with a 3mm full suit, my freedom plate, and a LP121. With 1500psi in the tank, my 30lb wing had the OPV going and I still had to skull a bit to stay at the surface. It's not a dangerous configuration though since I can still kick the whole rig to the surface if I had to, but most people don't sink like bricks.
AL100's are about the same buoyancy wise as the steel tanks but weigh like 10lbs more than a HP100 steel, and are about the same size/weight as a HP130, it's stupid.

I'm for sure going with the Steel 100's. The finish on it is the last part to figure out. I was talking with DGX last night and they mentioned the hot dipped galvanized get mottled very quick and do not look great but is the best durability option...does anyone have a picture of what that looks like when mottled and worn? The other option was a painted finish over a hot spray galvanized which was stated as the best cosmetic option. I would guess most steel tanks Ive rented have had painted finish.

 

[Marie13]

Get the HDG. You do not want the painted over the HDG. They chipped easy just with being shoved in and out of my SUV.

 

[tursiops]

A new AL100 is much more expensive and somewhat available.

AL100s are really heavy, need 3300 for a full fill, and can't be overfilled. Steel 100s are a much nicer tank.

 

[undrwater]

The hot dipped galvanized become beautiful with age. Because you can keep diving them.

Honestly, I don't think they ever look ugly. But they just keep going.