Hygiene - Steel vs. Aluminum

[belgianbrew]

After reading a allot about the buoyancy, and longevity characteristics of the two materials, I'm still puzzled as to which is better for one's health? Aluminum is a poisonous metal, but it's more corrosion resistant in sea water. However steel is inert, but highly prone to both internal and external corrosion in sea water. Frankly the idea of breathing out of a vessel that could potentially have unseen rust in it disgusting! I mean this is life support here. Any one know any data on the subject, and should this influence my purchase?

 

[socaldiver77]

Hello, I have both tanks and dive regularly in Southern California Pacific Ocean. When it comes to buoyancy the steel is more stable and uniform through out the dive. Now, what I learned with some older guys here is to avoid leaving tanks with less than 500PSI of air on it. It will be more prom to get corrosion regardless of what tank you use if you are always leaving them close to empty. Also, it is very important to complete preventive maintenance such as visual inspections, avoid dropping the tanks and whenever the air doesn't smell and taste good.

CB

 

[belgianbrew]

Now, what I learned with some older guys here is to avoid leaving tanks with less than 500PSI of air on it.

I've heard that too from divers around here in the north east, except don't go below 200psi. Steel is the preferred cylinder material up in these parts, but so being neurotic .

 

[roakey]

When it comes to buoyancy the steel is more stable and uniform through out the dive.

Could you elaborate on this statement?

Roak

 

[Plumb bob]

..... Frankly the idea of breathing out of a vessel that could potentially have unseen rust in it disgusting! I mean this is life support here.....

Sheesh you seem a little on the precious side to be diving, after all, billions of creatures eat, sleep, procreate and defecate in the stuff your swimming in... A little rust is nothing, do you check what is upwind of you before breathing?

 

[Colliam7]

I'm still puzzled as to which is better for one's health? Aluminum is a poisonous metal, but it's more corrosion resistant in sea water. However steel is inert, but highly prone to both internal and external corrosion in sea water. Frankly the idea of breathing out of a vessel that could potentially have unseen rust in it disgusting! ... Any one know any data on the subject, and should this influence my purchase?

This issue comes up periodically, but is not an easy target for a search of older threads. Concern about health issues should not influence your tank purchase decision - air capacity, bouyancy and trim characteristics, cost, etc., are more important factors. While aluminum toxicity is, indeed, a human health risk in certain situations, there are no data indicating that there is any systemic absorption of aluminum associated with breathing air from AL containers, under pressure. The amount of aluminum oxide that forms is very modest to begin with, most / all of it that might somehow manage to become airborne in the tank is captured by the regulator filter, and there is simply no indication that it is a clinical issue. The ferrous oxide that forms in steel tanks is more visible, probably more extensive, etc., but still not a health concern. The only concern might be a partial occlusion of the filter on the regulator by rust particiles, but that is a relatively easy 'fix'.etc. A steel tank with a coating of rust on the interior surface is disgusting to look at, the appearance of water used to clean it is unappealing, but rust is not a health issue, at least not on the basis of inhalation related to scuba diving.

 

[belgianbrew]

Thanks all, I'm going steel, and like all my necessary equipment clean and maintain it religiously. I know it was sort of a strange thing to ask, and you may notice it was posted past midnight. I think I just didn't want to leave a stone unturned with the decision.

 

[SparticleBrane]

Hello, I have both tanks and dive regularly in Southern California Pacific Ocean. When it comes to buoyancy the steel is more stable and uniform through out the dive. Now, what I learned with some older guys here is to avoid leaving tanks with less than 500PSI of air on it. It will be more prom to get corrosion regardless of what tank you use if you are always leaving them close to empty. Also, it is very important to complete preventive maintenance such as visual inspections, avoid dropping the tanks and whenever the air doesn't smell and taste good.

CB

 

[belgianbrew]

What he means is they don't become positively buoyant when empty.

 

[Jimmer]

What he means is they don't become positively buoyant when empty.

That's not entirely true, some steel tanks do go positive according to the spec sheets from the manufacturers.