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mm2002
01-03-2008, 18:53
I know the pony bottle thing has been beat to death, but I'd really like some opinions from experienced divers as to my plans for our (the wife and I) setup.
We had a spare air, and the intentions were for her to carry it. (I'm a worrier). After much research, we sold it and bought a 13 pony from ST. My plan is for her to carry it, and have it convenient if she or I need it (mainly her :*).
For the type of diving we do, it doesn't make any sense at all for both of us to carry a redundant air supply, but it makes me feel better if SHE at least has one. Vis can be pretty crappy here, and I've lost sight of her on more than one occasion, so this is something I really feel strongly about.

I'm considering the following two configurations:

1. Pony reg replacing her octo.
2. Pony, with the reg redundant to her octo.

I've already done the research leading to my decision on the bottle, and I'm not interested in "a 13 isn't big enough, I'd go with a 30", or "you don't need a pony", or the such. I'm just looking for some advice from experienced divers, and some possible circumstances I may have not thought out, which could make one setup better than the other.
My main concern is for my wifes safety. I'm old and expendable, but she's young and a great mother! :smiley36:

CompuDude
01-03-2008, 19:50
Look at it this way.

The octo is for you. True 2nd stage malfunctions are relatively rare... and she always has the pony, should one happen to her. In an OOA, she's going for the pony or for YOUR octo, not hers.

I would say regular reg+octo setup, and add the pony as a truly redundant system that can be brought along or left behind as the needs change. But that's just my opinion.

mm2002
01-03-2008, 19:52
add the pony as a truly redundant system that can be brought along or left behind as the needs change. But that's just my opinion.

Actually, that was my original intention. Thank you for the input!

skdvr
01-03-2008, 21:19
Look at it this way.

The octo is for you. True 2nd stage malfunctions are relatively rare... and she always has the pony, should one happen to her. In an OOA, she's going for the pony or for YOUR octo, not hers.

I would say regular reg+octo setup, and add the pony as a truly redundant system that can be brought along or left behind as the needs change. But that's just my opinion.

Agreed...

Phil

crosseyed95
01-03-2008, 21:35
Look at it this way.

The octo is for you. True 2nd stage malfunctions are relatively rare... and she always has the pony, should one happen to her. In an OOA, she's going for the pony or for YOUR octo, not hers.

I would say regular reg+octo setup, and add the pony as a truly redundant system that can be brought along or left behind as the needs change. But that's just my opinion.

Agree...

Daved
01-03-2008, 22:34
Complete redundancy! If she needs to supply another--the tank is off and gone and she is out of harms way with the person needing the air with the pony.

texdiveguy
01-03-2008, 23:02
I will start by saying I disagree with your idea that just one of you needs the redundant gas supply in terms of a pony bottle....but you are an adult and can make that choice on your own previous diving experience/training/wisdom.

Thumbs up to you though on your concerns for your wife and her safety!!!!

As to your question....let her keep both her second stages and add the addition of the pony bottle, never a bad pick.

terrillja
01-04-2008, 00:42
I agree with texdiveguy, IMO you each need your own pony, my dad and I each carry a 30cf, and we were required to each have a pony for our wreck diving class as well as the ice diving class we were signed up for, until they decided the ice was too thin and canceled it. (Don't get me started on the ice course)

So I'd say your future classes could somewhat dictate if you want to share a pony or each have your own.

Part of the reason why we each have a pony is because of my mom told us we weren't diving without them, and that was how it was going to be.

To finally answer your question:

I personally have just moved my octo over to my pony reg, rather than have 3 second stages. I think the key part is how you are carrying your pony, if it is slung and the reg is bungeed on it, having 3 would be ok. If it is behind you, attached to the main tank, then having the extra house could be a pain/entanglement hazard.

mm2002
01-04-2008, 09:16
I will start by saying I disagree with your idea that just one of you needs the redundant gas supply in terms of a pony bottle....but you are an adult and can make that choice on your own previous diving experience/training/wisdom.

Yes, I can see that angle too. Maybe we should both have one. I suppose my logic is that I have a little better breath control, and would be more physically able to get to her (or the surface) if I was OOA. I know I can get to the surface from 40 without air, but can she? I'm not sure I want to find out. All of our diving right now is <60 ft, and usually around the 35 to 45 area, and that has a great deal to do with my decision. Also, I have ended up doing a couple of solo dives, and in that case I could carry the pony with me.

I'm sure my logic and way of thinking reflect exactly what I am, a beginner! That's why I pick your brains! In 10 years people will be picking mine, and I hope to have some good advice for them.

No Misses
01-04-2008, 12:53
Go with option #2. Your pony should be a self contained system. You do not want to eliminate your octo to "make room" for the pony reg. You want to keep your original setup complete. This way if you dive without the pony, you will still have a complete kit.

I recommend attaching the pony second stage to the pony bottle via bungee cords (2). This will keep the hose neatly stowed and the second stage readily available.

I dive with the pony valve turned off. I pressurize the hose and check the pony pressure prior to the dive. By diving with the valve in the off position, I am confident that I will have a full pony when needed. There is no chance of a leaky second stage draining the bottle earlier in the dive.

On the last dive of the day, I usually switch to the pony at the end of my dive (on the bottom). This reinforces the fact that I can safely switch air sources, ascend from depth and still have air left in the bottle when I surface. This also helps with muscle memory.

As a test for myself:
I stop breathing on my primary (leave it in mouth just in case)
Reach back and locate my pony second stage (I have my pony back mounted & upside down)
Pull the second stage and hose free of the bungee cords
Turn on the pony valve
Purge and breathe from the pony second stage

If I can do all of this without feeling the need to breathe, I have done it quickly enough. If I had to take an additional breath from my primary prior to getting the pony deployed, then it took too long and I failed the test.

Good Luck.

mm2002
01-04-2008, 16:07
Why would it not be better to have the pony reg on a necklace, and routed under your arm along with the octo? If you're OOA the octo isn't going to do you any good anyway, so it should be reserved for your buddies needs, no? If you're OOA, you go straight for the pony reg.
Also, why not leave the pony valve turned on? It would seem to me that all the fumbling with turning on the valve behind you, and retrieving the hose and reg could be a lot of work in a stressed situation. What are the chances of your pony leaking out all of the air, AND your main tank being OOA at the same time? Murphys law?
I'm not arguing your ideas here, these are just the things that go through my mind.

CompuDude
01-04-2008, 17:34
Why would it not be better to have the pony reg on a necklace, and routed under your arm along with the octo? If you're OOA the octo isn't going to do you any good anyway, so it should be reserved for your buddies needs, no? If you're OOA, you go straight for the pony reg.
Also, why not leave the pony valve turned on? It would seem to me that all the fumbling with turning on the valve behind you, and retrieving the hose and reg could be a lot of work in a stressed situation. What are the chances of your pony leaking out all of the air, AND your main tank being OOA at the same time? Murphys law?
I'm not arguing your ideas here, these are just the things that go through my mind.

You want to be able to pass a pony off, so I would avoid a necklace for that reason. Necklaced secondaries are intended so the donor can donate his/her primary and switch to the secondary easily. In case of pony, if you donate, you're donating the entire thing. No need for a necklace that's only good for you.

Pony's don't hold a huge amount of air. It's too risky for a leak to develop and drain your tank, or perhaps partially drain your tank (leaving you insufficient gas, just as bad) if it's on and you're not watching it. Best to charge the hose to verify pressure and then turn it off, then you know for sure how much gas is in there, and that a leak or hose rupture or anything else will not drain the tank during the dive.

mm2002
01-04-2008, 18:04
So, if the ability to pass it off to another diver is important, then mounting in back by the main tank is worthless, right? So I guess that brings me to another question, where's the best place to mount a 13? By the main tank is out of the way and streamlined, but not very handy if you have to detach it, mess with the valve, or un-bungee the reg hose. I bought a mounting bag, and the BC has straps already in place to mount the bag. The bag was cheap, so it won't break my heart not to use it, so what's the best mounting scenario? Again, I really appreciate your help here, this is a very important thing for me right now.

CompuDude
01-04-2008, 18:31
So, if the ability to pass it off to another diver is important, then mounting in back by the main tank is worthless, right? So I guess that brings me to another question, where's the best place to mount a 13? By the main tank is out of the way and streamlined, but not very handy if you have to detach it, mess with the valve, or un-bungee the reg hose. I bought a mounting bag, and the BC has straps already in place to mount the bag. The bag was cheap, so it won't break my heart not to use it, so what's the best mounting scenario? Again, I really appreciate your help here, this is a very important thing for me right now.

There are "quick release" brackets designed so you can back mount but still pass it off, but I prefer slinging in front where I can see it any time I want. It would suck to have one of those mounts not release properly.

skdvr
01-05-2008, 06:00
I was using a Sherwood reg on my Pony and was told me a Sherwood rep that they recommend leaving the gas on with their regs because of the Dry Bleed system. That it could leak all of the pressure out of the hose. I never tried to charge the hose and turn it off to see if it actually would leak all of the pressure out during the dive, I just left it on. I just figured that since my pony is slung that if there was a problem I should be pretty quick to get it shut off... So I guess what I am saying is that weather or not you leave your air on or if you just charge the line and shut it off could depend on your reg.

You can buy all the stuff for the sling for just a few bucks too. I think I spent about $4 or $5 (I already had two bolt snaps), so you could build a sling and try it that way to and see which you like best.

MM2002, when ever I can get down there again I will let you check out my pony if you have not already made a sling for yours. I know that I have already told you that you can check out my BP/W so I guess why not the pony too :smiley20:

Phil

Hollywood703
01-05-2008, 06:38
I Bought a 30 cf tank, that I mounted to my tank, i have always used a octo inflator, so i just placed the pony octo, to my lower right side, I also liked the idea of my wife having the extra air, however, I just didnt want to give her all the extra weight.

Hollywood703
01-05-2008, 06:44
I was using a Sherwood reg on my Pony and was told me a Sherwood rep that they recommend leaving the gas on with their regs because of the Dry Bleed system. That it could leak all of the pressure out of the hose. I never tried to charge the hose and turn it off to see if it actually would leak all of the pressure out during the dive, I just left it on. I just figured that since my pony is slung that if there was a problem I should be pretty quick to get it shut off... So I guess what I am saying is that weather or not you leave your air on or if you just charge the line and shut it off could depend on your reg.

You can buy all the stuff for the sling for just a few bucks too. I think I spent about $4 or $5 (I already had two bolt snaps), so you could build a sling and try it that way to and see which you like best.

MM2002, when ever I can get down there again I will let you check out my pony if you have not already made a sling for yours. I know that I have already told you that you can check out my BP/W so I guess why not the pony too :smiley20:

Phil

I also have a sherwood First stage, what I do is Pressurize the line, then shut it back off. I too was advised to turn it on and leave it on, but with the bleeder hole in the first stage, even without use after 3-4 dives, you could have no air in your pony. I pressurize the reg, turn it off, unless I am ice diving........Then I leave it on....Something about that just makes me leave it on.

mm2002
01-05-2008, 10:48
I was using a Sherwood reg on my Pony and was told me a Sherwood rep that they recommend leaving the gas on with their regs because of the Dry Bleed system. That it could leak all of the pressure out of the hose. I never tried to charge the hose and turn it off to see if it actually would leak all of the pressure out during the dive, I just left it on. I just figured that since my pony is slung that if there was a problem I should be pretty quick to get it shut off... So I guess what I am saying is that weather or not you leave your air on or if you just charge the line and shut it off could depend on your reg.

You can buy all the stuff for the sling for just a few bucks too. I think I spent about $4 or $5 (I already had two bolt snaps), so you could build a sling and try it that way to and see which you like best.

MM2002, when ever I can get down there again I will let you check out my pony if you have not already made a sling for yours. I know that I have already told you that you can check out my BP/W so I guess why not the pony too :smiley20:

Phil

Thanks Phil, I appreciate that.

Grin
01-06-2008, 10:24
All are good points. You kind of have to decide how you want to do it for yourself. I have a Sherwood reg for my pony and I turn the valve on at the begining of my first dive of the day, then leave it on all day. I check it before each dive to make sure noone thought they were doing me a favor by turning it off for some reason. I have been diving the pony upsidedown on my back, so I can reach the valve in case it somehow does end up off for a reason I can't imagine, but you can't be too safe. I am contemplating flipping it back over(not upside down) for two reasons. One: My new pony bottle user fear of it somehow being off, has subsided. Two: With it configured/aligned exactly the same as my main tanks valve, it is real easy to check both valves, simultaneously before a dive, and not get confused which way your turning the valve.
I removed my primary backup 2nd stage for two reasons: One: This forces me to use the pony every dive. Which has not been a problem, as I feared originally, either. Two: I consider removing that thing a little bonus to clean up my operation from adding the pony rig(3 2nd stages for simple no-deco reef diving is getting a little crazy IMO).
I have a button gauge on the ponys first stage that I can quickly confirm the pressure has not drained somehow between dives. I have been diving the rig this way for well over year now(maybe two years?) and I have yet to find the pony tank drained even a little from the Sherwood bubbling thing or some sort of leak. It doesn't happen!
Everyone gets to decide how to set up the use of their pony the way they see fit for them, is the case. I prefer my pony 2nd stage being clipped to my right chest D-ring with the tank valve already on. I have found no reason to worry about the pony being empty when I need it, due to using it with the valve on, like I do. I definatly worried about this, at first also, but it has been discovered to be a non issue. I can easily dive it 10 days before it needs topped off. That's due to loosing maybe a couple hundred lbs of pressure from being turned on and off so many times, and maybe the Sherwoods bleeding/bubbling feature thing adding a little to that. Basically, when it need topped off it's past time to test it out anyways.
Set it up the way you want, and check and recheck and test it.
I dive with No-Misses alot. and he has the neck thing, and extra second stage on his primary, and runs his pony with the valve off. That is the DIR way and if your really going to tech dive or cave dive you really should follow their rules. I don't tech dive or cave dive, and I do it my way. Basically the exact opposite of the DIR spec. Both ways work for each of us.
I also bought a tanks crossover fill adapter for my pony, so I can top it off from a main tank myself. With this you can fill your pony with NITROX without having to get it nitrox scrubbed. And if you feel OK about it you will never need to pay to have a vis or anything to your pony. The biggest benefit is being able to top it off easily(even on the boat if you wish). I would actually prefer air in my pony, but I have no air tanks to fill from, so I use the lowest mix, like 30 Nitrox to fill it. I have also filled my itty bitty 6 cf pony to 3700 psi in the past. Maybe it's a 7 cf bottle now :smiley36:. But I actually went back to my 13 lately as it is the way to go for my style diving. But I still put around 3300, in the 13, crossfilling it from HP tanks. 3700 is a little much on a Yoke valve. When the button gauge gets close to 3000, I break out the crossfiller and filler up at home. I like it simple and quick. The simpler and quicker and easier and less cumbersome, the better, and the more likely you are to not leave it on the deck as many end up doing. I don't even question the pony anymore, it's part of my gear if I'm diving 100ft or 20 ft.

anvil
01-30-2008, 12:29
I dive hookahs a lot and if I am by myself no pony unless I am deeper than 40 ft, If my kids are with me then i take at least a 6ft with a combined 2nd stage reg direct on the bottle. This is on a tear away bag clipped to my weight belt.This is any amount for an emergency asscent.I often use a 13ft with reg and 2nd stage on a whip.This stays attached to me and I can buddy breathe if required without losing contact.I firmly believe that if you prepare for it it won't happen. Why would you need a 20 or 30 , in a situation you are going to be headying for the surface.Not mucking around
continueing the dive.You can still manage a safety stop on a 13.

MSilvia
01-30-2008, 13:09
Why would you need a 20 or 30 , in a situation you are going to be headying for the surface.Not mucking around
continueing the dive.
There are a number of reasons. For one example, if you're diving in a current from a boat on a mooring or anchor line, it might not be a good idea to surface directly if doing so would mean surfacing away from the boat when it would be unable to chase you until other divers are out of the water. Since you can avoid having to put yourself in that position by choosing a redundant gas supply that gives you the option of swimming back to the ascent line before surfacing, one could easily argue that that would be a sensible choice. Not surfacing immediately doesn't necessarily equate to 'mucking around'. Some dive problems are best addressed underwater.

Another reason would be if you were making deeper dives from a boat that required a redundant gas supply, as is common in this region. If it's a two dive charter, and you use your 13 on the first dive, you don't get to make the second dive. If you have a 30 or 40, you might very well have enough gas left in your pony to give you redundancy for a second dive as well.

cummings66
01-30-2008, 13:41
To address the bleed issue on Sherwoods. The specs say something like a max of 25cc's per minute is how much air you'll go though. It'd take a very long time to run it out of air.

Here's what I do. Open the valve on the bottle and then I dive, stop at the checkout spot to spot bubbles and final gear check, then I'll close the valve. As I descend I will reopen it every so often. On the way up I don't open it up, just on the way down. Basically you feather the valve to insure it always has air in the first stage, I'd do that with any makers first stage.

I have never noticed a problem, for example I have forgot once or twice to do that and went down to 90 feet and it was still bubbling away happily when I opened the valve.

I think the risk of a free flow demands you close the tank valve and open it every so often. Mine is slung by the way.

Grin
01-31-2008, 10:34
I turn my Sherwood ponys valve on at the beginning of my first dive of the day and it remains on until I derig at the end of the day. I do check to make sure noone thoughtfully turned it off for me between my dives, before going down again(a fear of mine). I notice no difference in pressure from the start. I top it off about every 5 th dive trip, and it barley needs it. I don't notice the bubbles at all, although I have witnessed them when checking to see if my Sherwood was a bubbler. It is. I use a 13 bottle.

fire diver
02-06-2008, 17:08
Why would you need a 20 or 30 , in a situation you are going to be headying for the surface.Not mucking around
continueing the dive.You can still manage a safety stop on a 13.

Msilvia hit the idea pretty well, but I want to throw out few more points for consideration.

No matter what sized pony you use, you need to make it has sufficient gas for a WTSHTF scenario. This most likely will not be a simple reg switch and head to the sunshine. Your breathing rate could easily be 3-4 times normal due to your OOA emergency. You may also NEED to get back to the anchor line to make your ascent. Your OOA may be caused by a ruptured hose or o-ring. This would result in a lot of "sound and fury". It may take you minute to get that problem sorted out and figure the best way out. You may loose vis and have to go slow at first.

You could really spend a lot of time "what if-ing", and you should, based on your current diving. Plan for the worst, hope for the best.

FD

terrillja
02-06-2008, 17:32
Why would you need a 20 or 30 , in a situation you are going to be headying for the surface.Not mucking around
continueing the dive.You can still manage a safety stop on a 13.
Overhead environments. If you are doing an ice dive or a wreck dive, it will be a bit before you can head to the surface. I never notice my 30cf on my back.

marchand
02-06-2008, 22:52
I also bought a tanks crossover fill adapter for my pony, so I can top it off from a main tank myself. With this you can fill your pony with NITROX without having to get it nitrox scrubbed. And if you feel OK about it you will never need to pay to have a vis or anything to your pony. The biggest benefit is being able to top it off easily(even on the boat if you wish). I would actually prefer air in my pony, but I have no air tanks to fill from, so I use the lowest mix, like 30 Nitrox to fill it. I have also filled my itty bitty 6 cf pony to 3700 psi in the past. Maybe it's a 7 cf bottle now :smiley36:. But I actually went back to my 13 lately as it is the way to go for my style diving. But I still put around 3300, in the 13, crossfilling it from HP tanks. 3700 is a little much on a Yoke valve. When the button gauge gets close to 3000, I break out the crossfiller and filler up at home.

How fast are you filling these ponys with the cross filler?

If by anything you mean hydro testing, then make sure I never get on a boat with you.

terrillja
02-06-2008, 23:07
I also bought a tanks crossover fill adapter for my pony, so I can top it off from a main tank myself. With this you can fill your pony with NITROX without having to get it nitrox scrubbed.

Makes sense, you are essentially using premix.


And if you feel OK about it you will never need to pay to have a vis or anything to your pony.

You have to be kidding, right? That is just stupid. You could have gotten some water in the pony, and it could be corroding inside. By your no-inspection method, you would never know. And if you are never having your tanks hydroed, that is completely crazy.


The biggest benefit is being able to top it off easily(even on the boat if you wish). I would actually prefer air in my pony, but I have no air tanks to fill from, so I use the lowest mix, like 30 Nitrox to fill it.

ok, makes sense, as long as you are diving within the MOD of EAN30, you should be fine


I have also filled my itty bitty 6 cf pony to 3700 psi in the past. Maybe it's a 7 cf bottle now :smiley36:. But I actually went back to my 13 lately as it is the way to go for my style diving. But I still put around 3300, in the 13, crossfilling it from HP tanks. 3700 is a little much on a Yoke valve.

Wait, 3700 in an aluminum cylinder? Are you crazy? Anything over 3000lbs is extremely risky. Don't bring one of your cylinders near me, especially if you never get them hydroed.


When the button gauge gets close to 3000, I break out the crossfiller and filler up at home. I like it simple and quick. The simpler and quicker and easier and less cumbersome, the better, and the more likely you are to not leave it on the deck as many end up doing.

I fill my pony one a year, when it gets its VIS done. Don't see why you have to fill your pony very often.


I don't even question the pony anymore, it's part of my gear if I'm diving 100ft or 20 ft.

Ok, this I can agree with. I have mine anytime I am going under the thermocline (25'-35').

Grin
02-07-2008, 08:21
Seems you are a little touchy there. I bet you didn't know you can do your own visual by simply unscrewing the valve and shining a light in there. And there are many people diving overfilled tanks all over the world. I dive slightly overfilled tanks all the time. It is very common for people to put 4000 psi in low pressure tanks rated at less than 2600. I don't go quite that far but many do. I do about 3000-3300 in my LP2600 rated tanks. Routine fills in AL 80s to 3500 are extremely common. If you only need to fill your pony once a year that explains your fear of everything. You probably should suck it down and test it once a month. Just turning on and off the valve will slowly drain the small tanks to needing topped off in a months time if you dive much at all. Hopefully you take a few breaths to verify the reg is even working when you do this before trusting your life with it. You should do that befroe every drop, if diving the valve in the on position, IMO. If diving with the valve off you still need to verify reg operation at the beginning of every day. Pony tanks are great but simply owning one does not make you safe. Ponies need alot of attention, and constant testing. If you simply trust it to work when you need it you may be in worse shape, owning a pony, than if you didn't have the very possible false sence of it being available no matter what.
Relax, The diving world will save you from yourself. Tanks are not exploding, and moisture / mold is not killing divers due to water in their tanks. If any of this were happening the entire scuba world would be cut in half in less than a year.
And when I fill the tanks with the crossfilelr I crank the valve open at a normal rate. I am not the only one in the world who uses these things. You can buy them form anywhere and they are very common. Many use them for many reasons. It's not like I dreamed this up and welded a disaster together in my garage.
A common use, other than filling ponies is: You do a drop and come up with 1200psi in your tank. You take a full tank with 3600psi in it and crossfill it into the 1200 psi tank to bring that tank up to 1800-2000 psi. Now you have a tank with a usable 2000 psi that you can actually get a dive out of(whereas 1200 is virtually usless). The tank that had 3600, now has 2500 or so. So you now have two tanks, to dive, instead of one. Very useful on trips where you have no onboard fill access and the trip is possibly a multiday trip. You might get 5 drops out of the 3 tanks you brought instead of coming in with 3 tanks with 1000-1200 psi in them, and only getting 3 drops out of them.

terrillja
02-07-2008, 10:19
Seems you are a little touchy there. I bet you didn't know you can do your own visual by simply unscrewing the valve and shining a light in there.

You can give a cursory inspection but without a proper light, mirrors and such, you really can't give a proper inspection.


And there are many people diving overfilled tanks all over the world. I dive slightly overfilled tanks all the time. It is very common for people to put 4000 psi in low pressure tanks rated at less than 2600. I don't go quite that far but many do. I do about 3000-3300 in my LP2600 rated tanks.

Overfills in STEEL cylinders are very common. They shorten the service life, but have been fairly safe. No argument here to overfilling steel cylinders.


Routine fills in AL 80s to 3500 are extremely common.

Where is that common? I have never seen a hot fill of greater than 3200, anything over 3K is very dangerous in an AL cylinder. I have never read anywhere or heard from anyone that overfilling an AL cylinder was common.


If you only need to fill your pony once a year that explains your fear of everything. You probably should suck it down and test it once a month. Just turning on and off the valve will slowly drain the small tanks to needing topped off in a months time if you dive much at all. Hopefully you take a few breaths to verify the reg is even working when you do this before trusting your life with it. You should do that befroe every drop, if diving the valve in the on position, IMO. If diving with the valve off you still need to verify reg operation at the beginning of every day. Pony tanks are great but simply owning one does not make you safe. Ponies need alot of attention, and constant testing. If you simply trust it to work when you need it you may be in worse shape, owning a pony, than if you didn't have the very possible false sence of it being available no matter what.

I test mine before every dive, and leave it on, but with a 30 the amount of air used is minimal.


Relax, The diving world will save you from yourself. Tanks are not exploding, and moisture / mold is not killing divers due to water in their tanks. If any of this were happening the entire scuba world would be cut in half in less than a year.

No, tanks are not exploding, because they are being taken care of properly. $10-15 a year for a vis is money well spent IMO. And as for the moisture/mold argument, that is because people are taking care of their gear, if the cylinder runs dry, you get it inspected.

I understand your reasons for having the crossfill. I agree that they can be useful, I just have serious apprehension about the lack of inspections on your ponies as well as your practice of overfilling them. Perhaps someone who does fills or inspections will chime in.

Grin
02-08-2008, 08:17
I do my own inspections on all my tanks. HAve not paid for one in over 4-5 years. On occassion I do my own Nitrox fills at my shop. At my request to vis my steel tanks, I was shown how they do inspections. I now do my own, whenever I feel the need. It isn't rocket science. Inspections are neccessary, but they are also a money making operation for dive shops. $15 for 2 minutes work. I probably inspect twice a year on my own tanks, right there at the dive shop in front of the guys who run it. I never drain my tanks before getting to the shop, just so the guys there know I don't suck my tanks dry. When I get there I crack the valves and drain them. If I'm curious, I unscrew the valves and look for myself. Usually curiosity gets everyone looking. If you think they are shinning mirrors in there and using scopes your wrong. If there water or rust you'll see it. I trust myself more than many dive shop personel. It isn't like these dive shop people went to school to do inspections.
Before I dove steels I got 3300-3600 in my AL80s virtually every fill from two different shops. AL 80s have 4000lb pressure plates, so they can only fill them to around 3800 hot, then they cool down to around 3300-3400. When you get 3600, you know they pressed the limits of the 4000lb plates.
I don't see why anyone would think putting 500-700 overfills in a AL80 is no more dangerous than putting 1000-1400 overfills in low pressure steels. Personally I feel the opposite.

teknitroxdiver
02-17-2008, 21:11
I don't see why anyone would think putting 500-700 overfills in a AL80 is no more dangerous than putting 1000-1400 overfills in low pressure steels. Personally I feel the opposite.

Steel tanks are steel, and aluminum tanks are aluminum. They are completely different and non-comparable when it comes to overfills. Overfilling does not hurt a steel tank. It permanently damages an aluminum tank. The properties of the metals are responsible for this, and it IS a fact.

ianr33
02-17-2008, 21:30
I don't see why anyone would think putting 500-700 overfills in a AL80 is no more dangerous than putting 1000-1400 overfills in low pressure steels. Personally I feel the opposite.

Overfilling steel tanks is common in Cave Country. Overfilling Al tanks is nuts and nobody in their right mind would do it.

From the Fillexpress website: Fill Express -- Frequently Answered Questions About Filling SCUBA Cylinders (http://www.fillexpress.com/library/fillfaq.shtml#procedures)

<<Will you fill my cylinder to more than its rated maximum pressure?
Fill Express does not overfill any aluminum cylinder. Overfilling shortens cylinder life, as well as increases risk of cylinder failure. Increased pressures also can cause burst disks, O-rings, and 1st stage regulator seats to unexpectedly fail prematurely. Willing to accept these risks in exchange for the increased gas volume, technical divers sometimes overfill their recently manufactured chrome-moly steel cylinders.>>

Those guys know what they are doing.

cummings66
02-17-2008, 21:44
I see several problems. First a vis should take more than 2 minutes, it's a lot more than just looking for rust inside, especially if it's O2 cleaned or gets PP fills. I saw no mention of many of the tests that luxfer wants done in a visual inspection, and that guide can be downloaded for free from Luxfer. I suggest any diver who owns tanks to get it and verify that the shop doing the inspection is doing it completely. Grin's shop isn't as many aren't.

I do know that the non trained dive shop vis is essentially look at the insides, checking to see if the threads are damaged and that's it. Look at Luxfers website and they have some docs for things that are done, they even make you do do measurements the depth of pits and use magnifying mirrors.

Overfills in AL tanks are either a mistake because he just filled a steel tank and didn't look, or doesn't know how dangerous it is. Grin's in FL and I believe he has found a shop or two that do this, but I hope it's the exception.

Grin
02-18-2008, 08:11
Generally I get about 3300 in Al80s from both my local shops. My buddies use Fill Express and they get 2900-3000 in their Al80s. I don't live close to Fill Express. I hear what you guys are saying, but I am not changing. I feel anything under 3400 in a AL 80 is fine. I agree the 3600-3700 is more than what is acceptable, but I've only had that a few times. And overfilling steel tanks is not completely acceptable without ramifications either as someone stated there. Obviously it's more accepted practice. I still see no issues with doing your own visuals, if your capable, as it's not rocket science. There are a million visuals done, that people pay for, and they probably dont get as much attention as you would do on your own tanks. Just make sure you do it right. If you don't suck your tanks dry and your shop services their compressors correctly you will find the inside of your tanks looking like new. I consider it smart to vis your own tanks as you know the shops integrity by the look of the insides of your tanks. Why not take a look and see for yourself? If your worried about your visuals being super involved you probaby should just do them yourself. they call it a "visual" for a reason. None of my Al tanks have any pitting in them. The threads look like new and I always have the guys at the shop lube the threads(with the proper lube) and screw it back together.
I claim too many people trust shops to do things they should be alot more involved with. Like visuals, and reg services.
Just to make everyone happy i will refrain from more than 3400(I'll strive for 3200-3300) in my AL80s form now on. You are correct about that!

cummings66
02-18-2008, 09:04
You might be the right person to ask this, in your visuals of your overfilled tanks, when you check them for bulges, bow and dents have you noticed any?

You are right it's a visual because you look at the tank, I've been shown how to do them but I do not have formal training in it which I will get this year. I know it takes more than a couple minutes because in addition to looking you're also measuring things. Some of those pits are .03 inches deep, that's very small and hard to do without tools for the guesstimation. I say that because you can't really measure it but instead you use this plate with dimples in it and the pick to compare "feel" and gage it that way. In addition to pits you've got to measure small dents which are so small you may not even know they're on the tank. I was shown some tanks that way. Bump a tank against something and there is the chance you have a dent which can cause it to fail a vis. I'm guessing it's not common or there'd be a lot of broken tanks out there, but I have seen them.

By the time you're done rolling the tank, using a straight edge on it to check for bulges and dents, count the neck threads and compare to a chart for how many are needed based on psi, looking for spots or dots of corrosion that are only .03 inches deep (which most tanks can have after being used for a while) you're going to have invested more than a few minutes into the process.

The guy that showed me how to do it was pretty anal and followed the procedures to the letter. I don't know how to do steel tanks which are what I own, at the time I had al tanks and that's what we did. My steel tanks appeared to undergo a very similar procedure but I have no documentation of standards on it so I can't speak with certainty as to what is acceptable or not. Only that mine according to them are good.

I've been tempted to buy the CGA C6 handout to find out what exactly I should have, I don't know but will check on the course I intend to take if they give you a copy or not. I know it costs around $100 if you are not a member.

Deep VI
02-21-2008, 09:58
This thread has gone a little off course. For your original question. ST has a great quick release pony bottle mount called the Quick Draw Pony Bracket for around $120. I have a 19cf on the way to add that extra bit of insurance. For the depths I dive, 70-100', that should give me enough air for a regular accent w/ a safety stop.

Grin
02-21-2008, 11:59
The Quickdraw is a excellent pony holder. I will sell this one for $75. I use Zeagle straps now. The Quickdraw allows you to remove the pony super easy to rerig your settup on a new tank. The Zeagle straps are not worth the effort to remove the pony when rerigging. It's a matter of what's important to each person. Some want to remove the pony to rerig and some find the hassle of rerigging with the pony still attached to your BC straps not a big deal. if you want to remove and reinstall it, super quick and easy, the Quickdraw is hard to beat.
If anyone want's it, IM me. It's like new. For a 13 or 19 bottle.