Permanent MOD markings on tanks

[gianaameri]

So long as the tank is properly marked, who cares how it's done?

If it is "permanent" - any system is fine.

Sticky tape is never permanent.

I'll post some pictures of my bail-out tanks when I get them back from the cave (now in safe storage in the cave awaiting for the next dive).

I stage them and leave them staged underwater for up to 10 days of cave diving.

The haloclyne is so corrosive that it strips the paint off and it will eat into the metal if left long enough.

The cave was originally marked with directional arrows by Martin Farr - made of aluminum.

All such directional "old style" arrows are gone. Eaten up by the cave.

What works works, but it has to be permanent, and it all depends also on the diving you do.

I prefer a system which works all the times in all environments including when I leave my tanks unattended and some drunk or idiot or wanderer has come across my tanks (no sticky label, nothing he can mess up with).

[gianaameri]

So, if group analysis is the answer, then marking the tanks your way or mine, will not make one juicy tasty little morsel of a difference in the outcome.

If your MOD marking is permanent, it is fine.

Why do you want to add to it a piece of Duct Tape with information you believe to be relevant which can come off and/or be source of confusion?

[Tegg]

If it is "permanent" - any system is fine.

Sticky tape is never permanent.

I'll post some pictures of my bail-out tanks when I get them back from the cave (now in safe storage in the cave awaiting for the next dive).

I stage them and leave them staged underwater for up to 10 days of cave diving.

The haloclyne is so corrosive that it strips the paint off and it will eat into the metal if left long enough.

The cave was originally marked with directional arrows by Martin Farr - made of aluminum.

All such directional "old style" arrows are gone. Eaten up by the cave.

What works works, but it has to be permanent, and it all depends also on the diving you do.

I prefer a system which works all the times in all environments including when I leave my tanks unattended and some drunk or idiot or wanderer has come across my tanks (no sticky label, nothing he can mess up with).

Like I said... if you dive in acid water and leave the tanks there for extreme amounts of time, then modification for how you mark tanks is needed. If one is carrying a tank into a cave and not leaving it there for extended periods of time, then the method I use would work fine.

Either way, people should do what works for them in the environment that they dive. Pretty simple.

BTW, I have left my tanks in water both salt and fresh for long times and found that my painters tape held just fine. (several days)

[JamesK]

If your MOD marking is permanent, it is fine.

Why do you want to add to it a piece of Duct Tape with information you believe to be relevant which can come off and/or be source of confusion?

I don't add the MOD to the duct tape. I add the the actual mix percent, the date I analyze it, and my initials. This is done as a verification that tank has been properly analyzed and when it was last analyzed.

[Bobby]

If your MOD marking is permanent, it is fine.

Why do you want to add to it a piece of Duct Tape with information you believe to be relevant which can come off and/or be source of confusion?

For stage cylinders below 130 feet the MOD is on the side and the neck of the cylinder. For 130 and shallower I use duct tape on the neck which I explained in an earlier post. Another reason for the permanent marking for the deeper stages is that the ascent rate is fast and the stop time short and critical. Shallower the ascent is slower and an extra minute or two to pull a cylinder to check MOD if the neck marking was missing is not an issue. With stages below my SM cylinders I can see the neck by pulling the cylinder down a bit. With top mounted stages I need to pull the top clip to get them out enough to see the neck. For top or bottom I can't see the side of the cylinder without pulling both clips and moving the cylinder in front of me.

If I am mixing 32/whatever for 130 feet and it comes out to be 29/whatever I will go with that mix however I want to know what the percentage came out as and plan the schedule accordingly. Anything deeper than 130 feet and it comes out on the numbers or I will remix until it is right.

This is just how I do it and feel comfortable with the system. Exactly how cylinders are marked is not what I believe to be the main problem. Taking a cylinder marked for a shallower MOD than it is planned to be used is one of them. Not analyzing any cylinder to confirm the mix before the dive is another. Agreeing to dive with a teammate that has done either or both of the first two is a third critical error. I have enough cylinders that some of them may not be used for over a year or so. Even with the MOD markings and analysis on them I would recheck both pressure and mix before using any of them.

One last thing that we now always do it check everything for CO. That is something that should be added to everyone's procedures IMHO.

[gianaameri]

I don't add the MOD to the duct tape. I add the the actual mix percent, the date I analyze it, and my initials. This is done as a verification that tank has been properly analyzed and when it was last analyzed.

Then you store it till you next use it and you and your Team/Buddy go diving without re-analysing that tank?

[gianaameri]

One last thing that we now always do it check everything for CO. That is something that should be added to everyone's procedures IMHO.

You should consider checking for CO2 as well because the better and proper filtering systems would convert any CO from the compressor into CO2.

So, depending on the filtering system, and if you have one of the better ones, if your compressor produces CO, you will find no CO in the tank, but excess CO2 (above 0.03 - 0.05%).

[Pavão]

If your MOD marking is permanent, it is fine.

Why do you want to add to it a piece of Duct Tape with information you believe to be relevant which can come off and/or be source of confusion?

I don't add the MOD to the duct tape. I add the the actual mix percent, the date I analyze it, and my initials. This is done as a verification that tank has been properly analyzed and when it was last analyzed.

Hopefully he finally understood what everyone is telling him.

[JamesK]

Then you store it till you next use it and you and your Team/Buddy go diving without re-analysing that tank?

No. I do not store full tanks. I get my fills the morning of the dive 90% of the time. If I do it before hand, they get re-analyzed before the regs go on as I am gearing up for the dive. However, having the tape there shows the days the fills were done.


Sent from my iPhone using Tapatalk 2

[PfcAJ]

Then you store it till you next use it and you and your Team/Buddy go diving without re-analysing that tank?

Negative. Analyze it again.

My usual routine is to analyze it, date it, and it if doesn't get used with a day or two of the analysis (date is marked on the tape), it gets re-analyzed.