"neutral" AL80s

[spectrum]

The concept of the Aluminum Neutral 80 is like polishing a turd.

The AL80 is already a heavy cylinder for what it holds. That's weight, not buoyancy and I'm comparing it to an E7-80, high pressure steel cylinder.

So what did they accomplish with the neutral 80?

*They added enough metal to the cylinder to integrate enough weight to make it neutral.
*In order to not further increase displacement and add buoyancy the the extra metal was added to the inside of the cylinder. This also kept the external size from getting any bigger.
*Now the cylinder has less space inside however the heavier walls afford the oportunity to increase the working pressure to 3300.
*The 3300 PSI rating lets you pack the same 77.4 Cf (not 80) of air into the cylinder.

So now you have a very heavy cylinder in terms of topside activity as well as swimming mass and you need what is effectively a high pressure fill.

You are better off taking a camband and strapping 4-5 pounds of weight to a common Al80. You get easier fills and it's your choice where along the cylinder the 4-5 pounds go, you can use it as a trim setting feature.

http://www.huronscuba.com/equipment/scubaCylinderSpecification.html

Pete

 

[Hoosier]

Here is "H" NEUTRAL TANK.

 

[Codyjp]

i think i will buy a steel tank. when AL80's are so easy to find to rent it is hard to even justify owning one. now a neg. boyant tank (cold water diver here) is really a better option. it weights more but with the neg. bouyancy you don't need to carry extra weight so in the long run you are better off.

 

[USCG flyer]

I'm with the folks that strap a weight on. Take an old weight belt and slide a 3-4 pounder on it. I tried a trim weight pouch, but it's a pain to get the bag into. Now I use a rubber coated hard lead. It stays put and it only takes a second to put on.

 

[dwaters]

I own a "sherwood" Catalina AL-N80 and as stated before with the heavier wall = less
cu. inches inside so you have to get the 3300 psi cool fill to get your 77.4 cu. in. of air.... so on most boat dives I'm lucky to get a hot fill of 3000 psi so I get shorted 5 - 10 cu. in. of air. P.S. After only 30 dives I went ahead a bought steel. My pretty blue "neutral" 80 will only be my back up. IMHO don't buy it...if it's a cost thing then buy standard AL80 and add 2-4 lbs on the tank.

 

[Dive1Dennis]

Buy a steel tank. Better buoyancy characteristics than any aluminum tank. My AL80s have been turned into backups......

 

[tracker]

The concept of the Aluminum Neutral 80 is like polishing a turd.

The AL80 is already a heavy cylinder for what it holds. That's weight, not buoyancy and I'm comparing it to an E7-80, high pressure steel cylinder.

So what did they accomplish with the neutral 80?

*They added enough metal to the cylinder to integrate enough weight to make it neutral.
*In order to not further increase displacement and add buoyancy the the extra metal was added to the inside of the cylinder. This also kept the external size from getting any bigger.
*Now the cylinder has less space inside however the heavier walls afford the oportunity to increase the working pressure to 3300.
*The 3300 PSI rating lets you pack the same 77.4 Cf (not 80) of air into the cylinder.

So now you have a very heavy cylinder in terms of topside activity as well as swimming mass and you need what is effectively a high pressure fill.

You are better off taking a camband and strapping 4-5 pounds of weight to a common Al80. You get easier fills and it's your choice where along the cylinder the 4-5 pounds go, you can use it as a trim setting feature.

http://www.huronscuba.com/equipment/scubaCylinderSpecification.html

Pete

Very useful info. Thank you very much.

 

[cerich]

My bad, misread. Either way, the bottom-weighted design doesn't seem optimal, and I'm not sure a top-weighted design would be much better, particularly since I would be using these to put together a set of doubles. Guess I'd have to try them first.

A

for doubles I would use standard alm 80's the neutrals will make you pretty butt heavy and trim more difficult.