Question Do we need environment sealed first stages ?

[BoltSnap]

Boltsnap is talking about clear blue water in the tropics. And in my experience the Mediterranean is in the same category. In this kind of environment divers can enjoy a reg like the Mk25 for the performance, hose routing and quite cheap maintanence cost.

In Libya (and North Africa in general), we face two distinct challenges:

1. Sand: Sand is omnipresent, infiltrating everything before and after you get into the water. The nickname "Grand Desert" is well-deserved.
2. Salinity and Corrosion: The Mediterranean's salinity exceeds that of the ocean, leading to more intense corrosion and verdigris. Even our so-called "fresh" water is heavy with minerals. Properly rinsing dive gear requires bottled water, which is seldom used.

This means that there is much higher "abuse" of the regulators, and dive equipment in general, than many other place with more ideal environment.

 

[BoltSnap]

"Grand Desert"

Many people in the US refer to it as "the Sahara Desert," which is a bit redundant. The word "Sahara" in Arabic means "desert," so saying "Sahara Desert" is essentially saying "Desert Desert." The correct name for this vast desert in our region is the "Grand Desert" or "Sahra El-Kubra," which translates to "Grand Desert."

 

[Geo7]

In Libya (and North Africa in general), we face two distinct challenges:

1. Sand: Sand is omnipresent, infiltrating everything before and after you get into the water. The nickname "Grand Desert" is well-deserved.
2. Salinity and Corrosion: The Mediterranean's salinity exceeds that of the ocean, leading to more intense corrosion and verdigris. Even our so-called "fresh" water is heavy with minerals. Properly rinsing dive gear requires bottled water, which is seldom used.

This means that there is much higher "abuse" of the regulators, and dive equipment in general, than many other place with more ideal environment.

A clarification about the sand: Beach diving in the Mediterranean was easy on my regs as long as I rinsed them. There were no waves, so the sand stayed on the bottom. Now living in California, there are always waves in beach diving, and the vis in the surf zone is zero from all the sand and silt in the water. This is the harshest environment (on gear) that I dove in. Boat diving in California does not have the sand problem.

Growing up diving in european freshwater lakes was easiest on the gear...

 

[Eric Sedletzky]

...Then there is also the aspect that if the piston Oring glides over a surface with abrasion or corrosion products, a part of it can get into the air and thus into the lungs of the diver. This will probably be so little that no harm is likely, but it remains an uneasy feeling.
However this applies in general to all inner surfaces of respiratory systems.

I would worry about impurities in the tank and your breathing gas way before I'd worry about metal dust from the large piston O-ring wearing away metal that might enter your lungs and cause all sorts of angst. Not only that, the LP pressure behind the piston will want to constantly push grit away/out as the piston moves back and forth.
This right here is the seed of the scenarios that become such a critical reality in the parallel universe known as the mythological fantastical world of scubaboardia.

During normal breathing the piston moves very little to supply flow. The piston shaft diameter is fairly large with a large circumference so a lot of air with flow by with just a crack of movement. Most of the wear in a piston body happens when you depressurize the reg with grit still in body from a previous dive and the piston moves to it's unpressurized resting position. Then the grit can get further in where the piston would never be when it's pressurized. So you just have rinse the ambient chamber really well if you rinse unpressurized. Get a spray bottle and get some flow going through instead if just dead water space. I soak all my stuff pressurized then soak overnight and force fresh water through the ambient chamber with a hose. I also don't change out tanks on site, I have several rigs ready to dive sitting on the beach, and when I'm ready to do a second or third dive I just grab a fresh rig.
Another way those ditches you see @rsingler post pics about happen when regs are allowed to dry out and silicone gone, then they are used in salt water and not rinsed properly and the salt sits under the O-ring and corrodes micro pits in the metal. Time to get the micro mesh out.

 

[CG43]

There were a couple of incidents around that time and the CBS got blamed for it. Back then the system wasn't as clever as it is now and had for example trouble with rapid depth changes among other flaws. Sherwood wasn't really responsive in this regard and ignored most concerns raised in this market back then. They did lose a fair chunk of their German speaking market due to that.

I suspect the main reason for the problems that occurred was the recommendation to set the IP to 7 bar during cold water dives and not as usall 10,5 bar or 11bar. I have read this recommendation myself, but can no longer find it and do not know who it comes from.
If the diver turned on the cylinder at a depth of 50 m and the sinter filter in the piston was somewhat corroded, the IP started at 2 bar slowly raising what is not so funny until 5 or 7 bar is reached.

The reason I opend my Sherwood 1. stage had nothing to do with that stuff .
The sealing surface for the rubber CBS popped had two scratches!
There would always have been a small amount of water penetrating, which means I would have had to throw away the stage. Throwing away an interestingly compensated flow by piston stage, where I only need to drill 6 holes to restore the function, no I can't do this !
Nevertheless I don't even know how many regs. I have

 

[Bigbella]

Many people in the US refer to it as "the Sahara Desert," which is a bit redundant. The word "Sahara" in Arabic means "desert," so saying "Sahara Desert" is essentially saying "Desert Desert." The correct name for this vast desert in our region is the "Grand Desert" or "Sahra El-Kubra," which translates to "Grand Desert."

Perhaps they were thinking of the Sahara Dessert, which probably involves some dates . . .

 

[BoltSnap]

A clarification about the sand: Beach diving in the Mediterranean was easy on my regs as long as I rinsed them. There were no waves, so the sand stayed on the bottom.

We have the most annoying very fine grain sand by the shoreline. It gets into everything. We don't dive when there are "waves" or "surf" but it gets to be very "sandy" in the water after a storm passes. I never dove in CA waters so I can't compare. My biggest issue here is actually our supposed "fresh" water we use to rinse our equipment, it isn't that "fresh" and is salty enough that we can't drink it and have to use bottled filtered water for drinking water.

It seems based on what you describe about CA diving from shore, you do have more challenges with sand that gets into regulators first stages. My point here is that even if your conditions are worse, you still maintain your regulators and have plenty of access to service centers. We don't have any of this but our regulators, Scubapro Piston first stages, still manage to keep going despite of the neglect and abuse they get without any type of "civilized world" maintenance.

 

[Geo7]

Ok, I understand... that sounds as harsh as here, as you said earlier.

You said the Mk25 1st stages last a long time over there. What about Atomics for a rental fleet, would you seal them in the conditions over there?

 

[BoltSnap]

What about Atomics for a rental fleet, would you seal them in the conditions over there?

Since becoming a dealer for Atomic in the late 90s in NY, I’ve exclusively brought in sealed first stages. That’s all I’ve ever used. Perhaps it’s time to bring in an unsealed one and see how it performs.

 

[happy-diver]

Yeah that's right put plenty of lube on your big oring so the fine sand, sticks to it and grinds your stuff

Sand – Seamap Australia

seamapaustralia.org

Fine sand:

particles of the Earths substrate ground over millennia, that you Can't See and can't play marbles with


Gotta love the thing about the Desert Desert, ha ha haa slow western people

Okay I'm off to the Automatic Teller Machine Machine to buy more dive gear


See and up there is the Libyan BoltSnap that actually knows the difference between brought and bought

although in this instance either could have been used


Hah ah ah ah ah ha ha!

At a hundred kilos of cast iron and wood and stuff I had to pull it apart again to put it where it was going

Magnificent!