Another Steel Question Into the Fray

[Windknot]

I know the steel/HP/LP/aluminum thing has been beaten to death many times over. But what the heck....a little spirited repartee is always enjoyable.

I have purchased a pair of OMS LP98's. They came banded and mainfolded with OMS 200 BAR valves and OMS Isolation Manifold. If you dont like 'em, so what. If you do like 'em, good for you, but so what.

I say that not to inflame, nor as an invitation to flame, but rather to set the tone for the question, and here it is.....(with a geographic preface)

I dive in the Great Lakes. I dive in fresh water lakes around the Great Lakes. I will NEVER haul my tanks across the country to dive away from home (read: Saltwater). I'd prefer to rent.

Much time and consideration has been given to the rusting problem that many associate with steel tanks. Is the rusting problem mainly in the salt water areas or is it universally damaging regardless of the salinity of the water you dive?

There.....that was simple..... 5 paragraphs to ask if my new steel tanks will rust slower, faster or the same in fresh water as salt.


Geeze....I gotta find something else to do with my time.

I anxiously await your replies.......

Windknot

 

[Rick Murchison]

I have had rust on an OMS 85 - one of a pair, so there was no difference in the diving conditions or in their handling from day one. They were used almost exclusively in fresh water but they were also used in salt water for a few dives, so that can't be totally eliminated as a factor. And salt water is far, far more corrosive (conducive to rust) than fresh water. One of the tanks just developed rust under the paint near the bottom of the tank - when the rust first showed through a crack in the paint the rusted area probably covered about two square inches. Luckily I caught it at the "surface rust" stage, and was able to clean it up without affecting the structural integrity of the tank.
As a result of this experience I stripped these tanks and repainted them with clear epoxy, so if any rust starts again I'll be able to see it through the paint. (Yes, I had 'em hydro'd after my work on 'em)
A word of caution - the paint that comes on the OMS tanks is really on there good, and stripping those suckers is not easy.
Rick

 

[Windknot]

Thanks Rick,

That was going to be my next question. I knew that there may eventually be a problem with the paint, but the deal on the tanks was just too good to pass up. (Buddy desparate for money, post divorce....felt kind of bad....well ok, maybe I didnt... but it sounds better that way.

I think that after I have them a year and bump them around i'll probably take them to a place that has the proper tools to strip them down.....my tool kit is pretty much a screw driver, pliers, telephone and checkbook to call and pay someone else to do the work.

Thanks again for the info, the warning and a solution.


Windknot

 

[budgy]

Regards rust, the steel tanks are best covered with a mesh to protect the paintwork. Reading inspection test reports, most of our clubs steel tanks have a little internal rust. Perhaps if we were more careful blowing out the valve and blowing out the filling hoses before filling, and making sure we never completly emptied the cylinder, it wouldn't happen. I have seen old tanks that required sand blasting and repainting to get through a test. I don't think you will see any appreciable rust for many years. We have quite a few Faber steel cylinders at our club that are six years old and more, they go in the pool and the sea nearly every week and show no external sign of rust damage. The climate here is quite damp, so you would expect things to rust easily.