Breathing Argon or Argox?????

[roakey]

From the GUE "Getting Clear on the Basics: Fundamentals of Technical Diving":

"Argon is twice as narcotic as nitrogen, but may have some applications as a decompression gas. Theoretically, by reducing the amount of inert gas counter diffusion into the tissues at depths greater than nine meters, shallow decompression stops could benefit from argox mixtures. However, there is very limited information and testing available to verify this claim. Argon is most commonly used for dry suit inflation where its density reduces heat loss."

"Getting Clear on the Basics: Fundamentals of Technical Diving" is available at www.gue.com.

Roak

 

[AquaTec]

when using argon as a drysuit gas only, has anybody ever heard anything about 100% argon in this aplication inhibits the deco process so therfor it should be mixed with at least 10% air or O2

 

[roakey]

Originally posted by AquaTec
when using argon as a drysuit gas only, has anybody ever heard anything about 100% argon in this aplication inhibits the deco process so therfor it should be mixed with at least 10% air or O2

Nope. What I have heard is that surrounding your body with Argon during a dive can cause "skin bends" through the process of "dysbaric counterdiffusion" (I think that was the term) coined, as far as I can tell, by IANTD's Mount. The theory is that the delta in partial pressures between the N2/He in your system and the N2/He-free gas outside your skin causes the N2/He to come out of solution near the skin surface giving you a rash that's indicative of skin bends.

The DIR folks have a different slant on the problem and call it “slobbitis.” You get skin bends because you have a layer of fat beneath your skin and for whatever reason N2/He does not eliminate as efficiently from this layer and you get skin bends.

Given the evidence gathered from the WKPP divers, their theory seems to stand up to scrutiny better than the fancy-sounding excuse given by IANTD.

Roak

 

[AquaTec]

So you are saying in one therory Argon may be a contributing factor and the other therory is that Argon has nothing to do with it.

It is true that He moves the slowest through fat so this makes since in that respect.

thanks

 

[wb416]

Originally posted by Lost Yooper
Here's a nice link describing why argon is used:

http://home.adelphia.net/~robworld/Why_Argon.htm

Take care.

Mike

Glad I took the time to read through it... brought up many interesting comparisons and reasons why Argon is the practical choice IF alternate drysuit gas inflation is desired.

 

[BILLB]

Isobaric Counterdiffusion is a more technical description of the skin DCS situation as mention in this thread. This means a change in pressure (in your body) without a change in depth. The original studies were done in a recompression chamber. At depths around 600 feet and deeper, a change in a "heavy" gas mixture to a "lighter" mixture (from neon/O2 to HE/02) resulted in the helium difussing through the skin! This resulted in blisters and extreme discomfort.

The technical diving community has used isobaric counterdiffusion techniques for accelerated decompression times. That is, switching from a helium/Nitrogen/oxygen mix to a Nitrox mix (lighter gas to a heavier gas). The heavier Nitrogen/02 mixture "kicks" out the lighter helium and on gasses approximately 50% slower than helium. The desired result is the helium is off gassed and the nitrogen is on gasses at a rate that can be handled later with the final 100% O2 at 20 feet (in other words a net loss of inert gasses in you tissues).

Argon would be an even better isobaric counterdiffusion gas (instead of nitrogen) if it was not so narcotic. Knowing what we know today, 100% 02 is the gas of choice for the final decompression stop. 02 has its problems too but managed correctly it is the best of all the alternatives.

Another gas that has been used for extremely deep dives is hydrogen. It has the advantage over helium in that it has not shown any properties of HPNS (high press neverous syndrome). To us laymen, this is the "shakes". A very serious problem especially when you are having to managed gasses, time and depth. The on set of HPNS is around 400 feet. Hydrogen also has problems. It is highly flammable on land and requires extreme safety processes when preparing this gas. Neon gas works well to but is extremely expensive.

Argon used at recreational depths has not show any problems as a drysuit gas.

 

[AquaTec]

Bill
Good come back and information, your explanation of the physics behind acelerated deco I have heard before, but forgot.
Thats the great part about this board, it keeps all this stuff up front.

HPNS is a real concern, I am not aware of Hydrogen being actively used in the deep diving comunity, I would be interested in finding out more. I will also send a couple of emails around.

 

[BILLB]

It was my pleasure on my ITC (NAUI) to have my final presentation assigned the topic "Isobaric Counterdiffusion". I will probably never realized the results of my efforts to understand this subject. However, it was an interesting subject and with a a lot of help from the WEB and from several universities, I ACED the presentation. The best part about the entire presentation is not even the ITC instructor was fully aware of all the facts presented.

 

[Green_Manelishi]

In addition to being expensive it is not an easy recompression
treatment if you become bent.