steel vs alum

[Bicster]

I want some E7-100's ... so far we've been diving with rented AL80's. The trouble is, I need to get cylinders for my buddy/wife too, so I can't see buying less than four. That's about $1400! :icon10:

Maybe next year. This is by far the most expensive hobby/sport/obsession I've had.

 

[spectrum]

Yea I know, that's why we got the E7-80s at $205 each. Almost all of our dive buddies are running 80CF or less so we really had no need to lug more gas for now anyway.

The good news is that with the entry of Worthington to this market with the SeaPearls/XS-Scuba offerings there is some downward price movement. Let's face it there is no way that it cost $144 to make that cylinder 4 inches longer!

Pete

 

[spectrum]

Here's a tank buoyancy calculator for those that need one.

http://www.subaqua.co.uk/cgi-bin/cylinder-buoyancy.cgi

Too many exceptions with such a limited data input. You're better off going directly to the data in a table such as: http://www.huronscuba.com/equipment/scubaCylinderSpecification.html

Pete

 

[Bicster]

Yea I know, that's why we got the E7-80s at $205 each. Almost all of our dive buddies are running 80CF or less so we really had no need to lug more gas for now anyway.

I don't feel like I need more than 80cf gas (except maybe with Nitrox) ... but I don't know if I can count on being able to get complete fills @ 3442 psi. An E7-100 @ 3000 psi is about 90cf, if my memory serves me correctly. That works ok for me. An underfilled E7-80 would be a problem.

The price discrepancy is ludicrous, but I suspect things may change for the better when PST gets their production ramped back up.

 

[Loneranger]

I got some LP Heiser steel 108's to get rid of my weight belt. I finally got one of them on a scale and they weighed 48lbs empty. Now I go straight to the bottom without a problem.

 

[Splitlip]

two things;

1. I dive in the northwest and I have heard from several people that steel tanks are better up here (I dive wetsuit). Why?

2. When I go to dive shops, I very rarely get a fill to 3000. Usually it is closer to 2800:wacko:. Is this enough of a difference to complain or am I just being picky? Is there any way to help, um, encourage a fill monkey to kick it up to 3000 without being rude?

Begin by refraining from terms such as "monkey" when referring to people. Some might consider that rude.

 

[spectrum]

I don't feel like I need more than 80cf gas (except maybe with Nitrox) ... but I don't know if I can count on being able to get complete fills @ 3442 psi. An E7-100 @ 3000 psi is about 90cf, if my memory serves me correctly. That works ok for me. An underfilled E7-80 would be a problem.

The price discrepancy is ludicrous, but I suspect things may change for the better when PST gets their production ramped back up.

I've been lucky on the air usage side. Also remember that the E-70 80 starts out as a full 80. The ubiquitous AL-80 is more like 77.4 CF and they are generally a few hundred PSI shy when cool. HP steel cylinder are a bit more prone to cooling losses but there is only 442 PS between them and the common aluminums. If you run into a shop that can't get past 3000 then you will come up shy. Meanwhile the 12 pounds of dead weigh you drop will give you an additional consumption edge.

I don't have anything against HP-100s. I just picked up a pair of the last generation 3500 PSI cylinders used.

Pete