This might provoke some discussion...

No, this is not something I'm planning on doing. It's just a "what if?"

When diving in salt water, I like to keep dives under an hour. Anything longer and I get terrible cottonmouth. Long freshwater dives are okay, because you can always swish your mouth with the water (stay upstream of buddies with p-valves), but that doesn't work too well with salt water.

We all know that the air in your cylinder has had virtually ALL the moisture removed from it. This is necessary to prevent rust or corrosion buildup inside the cylinder. Breathing this very dry air is what causes the cottonmouth.

Apollo makes a device that adds moisture before the air reaches the second stage, but those I've talked to that have used it say it doesn't work very well.

Consider this: What if one were to remove the cylinder valve, pour in an ounce or two of distilled water, and then fill it with air. Then, after making your dive or dives, you remove the valve, pour out the water, and dry the cylinder with a commercial dryer (I have access to one).

I wonder if this would add any moisture to the air.

On second thought, I might try this after all. Surely no damage could be done in just a day or two.

Any thoughts?

Russell

Seems like a lot of effort involved there, what with the need to dry the tank afterwards. Why not just take down a small hydration pack? When you start getting the cotton mouth you can take a sip or two. It does take a bit of practice to keep from drawing saltwater into your mouth, but it can be done.

Well I tell you what I have a Boi filter and I love it Plus when I dive salt water I dive my old faithful Sherwood Oasis and it also has moisture retaining fins inside the second stage. But yes I highly recomend the Boi filter it works fine for me and realy keeps me from getting cotton mouth. The only reason I do not use it in the cave system is of course the failure point. But if I dive peacock or shallow system I dive the Oasis and if I dive Ginnie then I go to the Apeks.

with all that work, you might as well just dive with a camelback velcroed to one of the tanks and simply put some good tasting orange gatorade in it... grab a drink whenever you need it and then simply stow the tube in a bungee...

all done... I do this for my >3hr dives in freshwater on my deco bottles. Works perfect and tastes good too... :-D

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Originally Posted by DeWayne

Seems like a lot of effort involved there, what with the need to dry the tank afterwards. Why not just take down a small hydration pack? When you start getting the cotton mouth you can take a sip or two. It does take a bit of practice to keep from drawing saltwater into your mouth, but it can be done.

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I've heard anecdotaly that some Tech folks in S FL are taking CapriSun packets on long deco SW dives...I have a box of 'em, but haven't tried that yet.

Personally, I've learned to take VERY small sips of SW to avoid Cottenmouth...

Norm

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Originally Posted by jammer

Well I tell you what I have a Boi filter and I love it Plus when I dive salt water I dive my old faithful Sherwood Oasis and it also has moisture retaining fins inside the second stage. But yes I highly recomend the Boi filter it works fine for me and realy keeps me from getting cotton mouth. The only reason I do not use it in the cave system is of course the failure point. But if I dive peacock or shallow system I dive the Oasis and if I dive Ginnie then I go to the Apeks.

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Jammer,

While I do adore my Sherwoods, I've never really noticed any moisture generated from that...

Do you have a link/sourcing on the Boi filter??

Norm

Rust forms pretty fast, unless you are talking abut 80s. If you forget to dry it out, you can kiss the tanks goodby.

Whatever you do, don't dive cold water like that. It will freeze up in minutes :(

I like DeWayne and Tegg's solution better :-)

Hey Russell,
I was a divemaster for a lot of years, and the trick I did was to suck on a jolly rancher hard candy. Tuck in in the corner of your mouth and it helps tremendously. There's something about the tartness that keeps your mouth moist.
John

Capri packs work OK, but depends where you deco because you do get a slight amount of the environement in. :)

You all seem to be missing the point. I have one of those SCUDA things (self contained underwater drinking apparatus). I bought it in the Keys back in the eighties, but never got around to hooking it up. It's easier to just keep dives under an hour.

It's all about the "science experiment" thing. Would water in the bottom of the cylinder put moisture back in the air?

DeWayne, you know it's not about the time and effort thing. Time is the one thing I have in abundance.

And I don't think distilled water in a steel cylinder would cause damage in one or two days.

Inquiring minds just want to know.

Russell

What about that device they sell in dive shops...it's called "scuda"....self contained underwater dringinp apparatus.....a little bag that is attached to your reg hose that has whatever liquid you want in it...

I have never used it or talked to anyone who has.....but I have seen em for sale.....they might jus be a bunch of bunk....but they are for sale out there.

1. The distilled water is at 3000 psi when you tank is full, I assume that will make anything more active.

2. Since the air is still under pressure in the tank it is not likely to absorb much water (maybe if the banks we a higher pressure than your tanks the air would re-absorb some water from the inside of your tanks.

3. Scary - what happens when you turn upside down? Do you pull water into your regs?? Make sure you have one of those little metal straws in your tank on your valve!

Yes it will put moisture in the air. What percentage of moisture you need is the question. It may be as high as 5%. Ask a respiratory specialist.

Then you will have to add the correct volume of distilled water.

If you have that much idle time on your hands then go for it and let us know how you make out. :)

PS- Don't try it in water/air below 45 degrees!!!!!

Take a "Rebreather Experience” class you will find the air is warm and moist.

I did a two and half hour dive and rig weighted 47 pounds total.
In a 72 degree pool I was fine with a 5mm suit, and a light weight hood.
No noise, warm and moist air….

http://cavediver.net/photopost/showp...cat=500&page=2

Just a thought.
Andrew

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Originally Posted by Sludge

You all seem to be missing the point. I have one of those SCUDA things (self contained underwater drinking apparatus). I bought it in the Keys back in the eighties, but never got around to hooking it up. It's easier to just keep dives under an hour.

It's all about the "science experiment" thing. Would water in the bottom of the cylinder put moisture back in the air?

DeWayne, you know it's not about the time and effort thing. Time is the one thing I have in abundance.

And I don't think distilled water in a steel cylinder would cause damage in one or two days.

Inquiring minds just want to know.

Russell

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I hear you Russell, but would you really want to go through the procedure of dismantling your tank before and after evry dive? If anyone has the equipment to spare for such an experiment, it would most certainly be you though :lol: The one thing that I did not like about the Bio filter was its use of charcoal. For me, higher FO2's and charcoal do not seem like a good combination. Perhaps you could design some sort of "bong" type apparatus where the air would actually cycle through water before being breathed. Likely similar to the bio filter, but if you could use a large enough chamber it just might provide the moisture you are seeking. If it did not work, at least you would have the makings for something to do post dive :lol:

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Originally Posted by Tegg

with all that work, you might as well just dive with a camelback

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Or carry a couple of those pouches of fruit drink that you punch with a straw to drink.

I want no water in my tanks.

so, you yhink that the pressure would turn the small amount of water into humidity? it seems that it may work, but I dont know if you would have any problems with your first stage, and what would the moister do to your guage?

First of all, I think the solution is more complicated than the problem. There are simple solutions to the problem; remember the KISS principal. Next, you want the water and air to mix in the tank. You want the water to evaporate. The way to make water evaporate is to reduce pressure, not increase it, or add heat. I don't think the air will absorb any of the water. Just my two cents.

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Originally Posted by cavediver

You want the water to evaporate. The way to make water evaporate is to reduce pressure, not increase it, or add heat. I don't think the air will absorb any of the water.

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That's what I was hoping to provoke - scientific reasoning. I believe you're right. Maybe I'll just dig out the old SCUDA.

Russell

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Originally Posted by normblitch

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Originally Posted by jammer

Well I tell you what I have a Boi filter and I love it Plus when I dive salt water I dive my old faithful Sherwood Oasis and it also has moisture retaining fins inside the second stage. But yes I highly recomend the Boi filter it works fine for me and realy keeps me from getting cotton mouth. The only reason I do not use it in the cave system is of course the failure point. But if I dive peacock or shallow system I dive the Oasis and if I dive Ginnie then I go to the Apeks.

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Jammer,

While I do adore my Sherwoods, I've never really noticed any moisture generated from that...

Do you have a link/sourcing on the Boi filter??

Here you go http://www.apollosportsusa.com/index.htm

Norm

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Here's another option, obviously not cheap or useful in a cave, but for the ocean it looks like it would work well.

http://www.oceanreefgroup.com/usa.htm

Fullface w/drink on demand pouch.

Looks kinda cool.

Get your fills from someone who uses a Rix.

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Originally Posted by Sludge

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Originally Posted by cavediver

You want the water to evaporate. The way to make water evaporate is to reduce pressure, not increase it, or add heat. I don't think the air will absorb any of the water.

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That's what I was hoping to provoke - scientific reasoning. I believe you're right. Maybe I'll just dig out the old SCUDA.

Russell

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Yes if you added water to the tank then the water would evaporate until it exerted its partial pressure as a gas up to its vapor presure.

I don't think it is accurate to say that reducing pressure will make the water evaporate faster, I mean if you pulled a vacuum on a cylinder of water then when you reached the vapor pressure it would begin to boil but whether you have HP or LP the water is going to equalize with its vapor pressure.

I'd think in a cylinder with enough water you would reach 100% RH

Look at it from the other extreme. You have a glass chamber and you have magnet holding a metal and glass beaker filled with water. You pull an almost perfect vacuum in the main chamber and then pull the magnet away and let the beaker fall and shatter inside the chamber and release the water. What is the pressure now in the chamber?

The water would have to be vaporized to get to you in the first place. The tank will tend to cool and I suspect keep most of the water condensed. I kind of doubt you would have enough reach your mouth to make a difference.

How about the nylon stocking mounted under the mouthpiece? Forrest, don't you use that? Can you tell any difference as far as it retaining a little moisture? Also handy to keep assorted crap out of your 2nd stage.

There is plenty of moisture in the air down here. Just bypass your filters on the compressor and let 'er rip. Guarantee you will get water/moist air in your tanks. :)

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Originally Posted by Sludge

. . .
And I don't think distilled water in a steel cylinder would cause damage in one or two days.

Inquiring minds just want to know.

Russell

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Distilled water has all the buffering minerals removed from it, and is therefore very corrosive! But -- if you leave the minerals in (tap water) you are likely to get mineral deposits on all the restriction points.

Water inside mechanical components is not a good answer!

WJH

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Originally Posted by Webmaster

The water would have to be vaporized to get to you in the first place. The tank will tend to cool and I suspect keep most of the water condensed. I kind of doubt you would have enough reach your mouth to make a difference.

How about the nylon stocking mounted under the mouthpiece? Forrest, don't you use that? Can you tell any difference as far as it retaining a little moisture? Also handy to keep assorted crap out of your 2nd stage.

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"WATER WOULD HAVE TO BE VAPORIZED" Makes no sense. On a molecular level liquid water will always chunk molecules off the surface, You will reach an equilibrium when the number of molecules that are leaving equal the same number of molecules that are slamming back into the surface and hydrogen bonding back with other water to form a liquid.

In a closed enviroment like a SCUBA cylinder Temp is going to make no difference in RH. if you have liquid water after equilibrium then you are going to have 100% RH!

Sludge has said he just wants to look at it chemically and is that context he is right. Oh I think he said scientifically.

It is in that context that I respond. Sometimes you got to look at things outside the box. He obviously doesnt understand that Pointing shotguns at people is ILLEGAL, but if he wants to talk about water.... then lets talk about it!

It should be funny to people that water is 18g/mole and butane is 54g/mole but water boils at 212@STP but butane boils @ 32@STP, Exact opposite of what you would expect. WHY?

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Originally Posted by Sludge

When diving in salt water, I like to keep dives under an hour. Anything longer and I get terrible cottonmouth.

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They used to sell a Sherwood "Oasis" regulator and also some other group made a gold foil grid that sat in your mouthpiece. Both condensed your exhaled moisture in the mouthpiece and effectively collected your gross vaporous drool to moisturize the air on your next inhale. Underwater drink packs and even regulators with liquid straws input into them have been used.

Thought for the day, since asked. Swallow now and then! I do a lot of long dives and have found that the simple act of swallowing as apposed to blowing out my spit seems to be all the lube I need. I was however VERY entertained by one support diver who when he forgot his swim suit served me juice on a deco dive buck naked! Sometimes I just flat love ya guys! Cindy :D

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Originally Posted by Cindy

I was however VERY entertained by one support diver who when he forgot his swim suit served me juice on a deco dive buck naked! Sometimes I just flat love ya guys! Cindy :D

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Well if I was bringing you drinks you would have to be the one that was Butt Naked LOL :D

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Originally Posted by crazyduck

Take a "Rebreather Experience” class you will find the air is warm and moist.

I did a two and half hour dive and rig weighted 47 pounds total.
In a 72 degree pool I was fine with a 5mm suit, and a light weight hood.
No noise, warm and moist air….

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One step ahead of you here.....I ordered a Megladon a few days ago. :-D

Mike

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Originally Posted by Jammer

Well if I was bringing you drinks you would have to be the one that was Butt Naked LOL :D

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I'll make you a deal Jammer. Carry my tanks on the next long dive I do and bring me juice at deco and I will bare my butt just for you. Of course you will have to tattoo "Cindy is my cave goddess" in a line arrow in oriental charactors, all spelled correctly of course and sign your name on my butt. Bring lots of ink! Cindy :twisted:

Cindy,
I'll serve you drinks naked too if the water isn't too cold!

Jammer will do the tattoo...

Just carry his gear. :smt046

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Originally Posted by JP

"WATER WOULD HAVE TO BE VAPORIZED" Makes no sense. On a molecular level liquid water will always chunk molecules off the surface, You will reach an equilibrium when the number of molecules that are leaving equal the same number of molecules that are slamming back into the surface and hydrogen bonding back with other water to form a liquid.

In a closed enviroment like a SCUBA cylinder Temp is going to make no difference in RH. if you have liquid water after equilibrium then you are going to have 100% RH!

Sludge has said he just wants to look at it chemically and is that context he is right. Oh I think he said scientifically.

It is in that context that I respond. Sometimes you got to look at things outside the box. He obviously doesnt understand that Pointing shotguns at people is ILLEGAL, but if he wants to talk about water.... then lets talk about it!

It should be funny to people that water is 18g/mole and butane is 54g/mole but water boils at 212@STP but butane boils @ 32@STP, Exact opposite of what you would expect. WHY?

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In relative humidity no, but we would be concerned with the actual humidity which would be expected to vary more or less directly to the T. Aren't we concerned with the total amount of moisture getting to your mouth? As you cool the tank the actual amount of water vapor within the tank will go down, more will be condensed as liquid water.

As to why it would 'HAVE TO BE VAPORIZED'; how do you expect to get it into the 1st stage, through the hose and out the 2nd, unless you're upside down and have enough liquid to stand over the dip tube, if it's not in a gaseous state?

In any case I think we could all agree that keeping the moisture outside the tank and 1st stage would be best.

Oh come on Marbry the guy just needs to get tough! Or swallow now and then. Gees, I do a few dives over an hour and sometimes I get so dry after deco my chest hurts. That's just part of the deal. So what do you think, Tattoo or not? Cindy :D

Cindy,

I would take you up on the offer but I know some of the places you have to carry the gear to! :)

On long dives in places with not so clean water I will strap a small camelback with gatorade to one of my deco bottles. Easy to drink from and it works well.

Mike

thanks all you guys for the ribbing LOL lets me know I am truely loved LOL but Cindy you left yourself wide open for a premo joke but I will be nice and remain silent LOL :-D

But wouldn't you have to do a double line arrow in there to either mark a jump from one cheek to the other or even a halfway marker to look something like this ( -<-l->-) LOL Just ribbing Cindy :-D

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Originally Posted by Cindy

Oh come on Marbry the guy just needs to get tough! Or swallow now and then. Gees, I do a few dives over an hour and sometimes I get so dry after deco my chest hurts. That's just part of the deal. So what do you think, Tattoo or not? Cindy :D

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Hmmm, maybe you could get a section of your favorite cave map tattoed on you. Of course that leaves much open as to its positioning relative to 'key features'.

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Originally Posted by Cindy

Quote:

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Originally Posted by Jammer

Well if I was bringing you drinks you would have to be the one that was Butt Naked LOL :D

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I'll make you a deal Jammer. Carry my tanks on the next long dive I do and bring me juice at deco and I will bare my butt just for you. Of course you will have to tattoo "Cindy is my cave goddess" in a line arrow in oriental charactors, all spelled correctly of course and sign your name on my butt. Bring lots of ink! Cindy :twisted:

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You have now a UW camera-man ready to document this!

<g>

Norm

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Originally Posted by Webmaster

Quote:

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Originally Posted by Cindy

Oh come on Marbry the guy just needs to get tough! Or swallow now and then. Gees, I do a few dives over an hour and sometimes I get so dry after deco my chest hurts. That's just part of the deal. So what do you think, Tattoo or not? Cindy :D

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Hmmm, maybe you could get a section of your favorite cave map tattoed on you. Of course that leaves much open as to it's positioning relative to 'key features'.

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Somehow, I am thinking about contour plowing here as a methodology...

nhb

Mike,
If you like there is a specific web page for rebreather’s divers at www.rebreatherworld.com it’s a fun bunch.

Congratulations on the purchase! Is Bird diving doing the training or someone else?

Did you order any special options?

Regards, Andrew

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Originally Posted by MikeH

One step ahead of you here.....I ordered a Megladon a few days ago. :-D
Mike

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Originally Posted by crazyduck

Congratulations on the purchase! Is Bird diving doing the training or someone else?

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Probably. I wanted to do it with Tom Mount initially, but his schedule is not exactly flexible...and mine is not either. Bird can meet my schedule to do the training.

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Did you order any special options?

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ADV(of course), HUD, mixed gas manual bypass(to be able to use offboard gas), and the diluent isolator valve are the options I ordered. Also, they are going to put an exhalation CL on the inhalation side for me, which will allow me to plumb it for an extra O2 sensor to run my VR3. Unfortunately, there's not enough room on the head to run a 4th...so this is currently the only way to accomplish this.

Any other options I want can be added at the time it's shipped....these are the ones that need to be pre-planned for.

Mike

I just noticed you said you ordered a rebrerather. You'll need to haul that puppy up here. I'm sure the 55deg water will help you appreciate the warm, moist air that much more.

BTW - you remember the cave you and TJ dove outside town here? A couple of other local guys were in there a few weeks ago, 25'+ vis.

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Originally Posted by Webmaster

I just noticed you said you ordered a rebrerather. You'll need to haul that puppy up here. I'm sure the 55deg water will help you appreciate the warm, moist air that much more.

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I'm sure it would. I'm planning a trip next summer up to NY to do some wreck diving with a good friend of mine....I think I'll REALLY appreciate it then on some of those dives with bottom temps in the upper 30's and lower 40's.

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BTW - you remember the cave you and TJ dove outside town here? A couple of other local guys were in there a few weeks ago, 25'+ vis.

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Sweet! That should have made it much easier to scout for side leads. That sure beats the 5' we had. How far has the line been pushed?

I'm definitely up for another trip up there in the not too distant future. Anything interesting planned in the next few months?

Mike

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Originally Posted by MikeH

I'm sure it would. I'm planning a trip next summer up to NY to do some wreck diving with a good friend of mine....I think I'll REALLY appreciate it then on some of those dives with bottom temps in the upper 30's and lower 40's.

Sweet! That should have made it much easier to scout for side leads. That sure beats the 5' we had. How far has the line been pushed?

I'm definitely up for another trip up there in the not too distant future. Anything interesting planned in the next few months?

Mike

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So far we have about 1600' in there, we'll be putting some more in soon. We're doing Windy River this weekend, but if you ever get a little time and just want to come up just let me know.