Method Exit bag and inert gas megathread

[GerMann]

Uhhh he was a german diver expert, his equipment costed extrem much money and knowledge.

 

[crova]

Uhhh he was a german diver expert, his equipment costed extrem much money and knowledge.

Yes, he knew precisely what he was doing.

BTW. Have you seen a video presenting exit bag? Watch it to get idea about the size you need!

I bought 18x24in and folded it down to 18x18in

 

[JWL]

this?
View attachment 6832

Minimum purchase of 100 bags will certainly allow a lot of practice runs...:-)

 

[crova]

Minimum purchase of 100 bags will certainly allow a lot of practice runs...:-)

I use this as an example what 200 gauge bag is. Many sellers from UK selling it. find the one who will sell you 5 bags, ask him for a 250 gauge sample and maybe size down: 150 gauge - choose the one which suits best.

 

[GerMann]

Thinking Betty´s Idee is good, but I will use a sweatter-Headband around my neck of course,

 

[Hush Sweet Charlotte]

Eek can anybody help? I just had my nitrogen delivered today but am not strong enough to open the cylinder valve, and can't ask anyone to do it for me. It's a wheel valve like this one https://www.adamsgas.co.uk/product/...ew-cylinder-for-wine-preservation-dispensing/

I called the supplier for advice but he just said to use brute strength, which due to my health problems I don't have. Can anyone think of a tool or anything that would help open it? All the cylinders from other suppliers use the same valve.

Aargh!

 

[crova]

Before you open it - please confirm you have pressure regulator installed!

 

[Hush Sweet Charlotte]

Hello Crova, yes I managed to get the right equipment set up, just totally thwarted by not being able to turn the valve no matter how hard I try!

 

[TheCrow]

Eek can anybody help? I just had my nitrogen delivered today but am not strong enough to open the cylinder valve, and can't ask anyone to do it for me. It's a wheel valve like this one https://www.adamsgas.co.uk/product/...ew-cylinder-for-wine-preservation-dispensing/

I called the supplier for advice but he just said to use brute strength, which due to my health problems I don't have. Can anyone think of a tool or anything that would help open it? All the cylinders from other suppliers use the same valve.

Aargh!

What about using one of those grippy rubber things used to open jars?

 

[Elek]

Has anyone tried to fill a tent with nitrogen? It looks less scarier than a plastic bag over the head, even thought it may require a lot more of gas (possibly more than 3000L vs 400L)

 

[GerMann]

Has anyone tried to fill a tent with nitrogen? It looks less scarier than a plastic bag over the head, even thought it may require a lot more of gas (possibly more than 3000L vs 400L)

If it were possible to fill up the tent with pure N, -but there is too much Oxigen in the air.
but what about this idea...

https://www.ich-zapfe.de/bierzapfen/stickstoffflasche-2-kg-mit-flaschencage/a-452064/

and fill up a 400 Liter solid plastic-trash-bag, put the head in it and then tape it air tight around the neck??

 

[Arak]

@GerMann ,

How many litres does it contain ? I don't see an indication.

 

[GerMann]

0,4 m³ (if it is normal standard filled)

 

[color_me_gone]

@Elek @GerMann @Arak
using any kind of sealed chamber filled with pure inert gas is NOT going to work for the following reason:

Even though you inhale pure inert gas, you continue to exhale CO2 until your death.
Residual O2 in the bloodstream and body cells continue the metabolism process.
CO2 is a byproduct of that metabolism.
The sealed chamber will eventually become severely contaminated with CO2 mixed with the inert gas.
This CO2 will be re-inhaled, and returned to the bloodstream.
Buildup of CO2 in the bloodstream will trigger the hypercapnic alarm of the body's self defense mechanism.
Even while unconscious, it will cause the body to struggle severely to get O2,
which will probably result in the involuntary destruction of your setup.

Continuous flow of inert gas is absolutely necessary to purge exhaled CO2 out the bottom of the bag.
Masks are not recommended. The diver has high quality equipment, and knew what he was doing.
I was looking into a respirator mask. @TiredHorse recommended against it,
Just too complicated and fraught with possible malfunctions.
While it would be nice to achieve this method without a bag over your head, the risks of failure are not worth it.

This is my method, and I have studied it considerably.

 

[color_me_gone]

https://www.amazon.co.uk/Helium-Canister-Balloons-Cylinders-Super/dp/B00JEA5LAQ

Thanks. This one on amazon claims 98% purity

I definitely NOT trust it to work.
I have often seen where the product changes, but eBay sellers never update their sales information.
Balloon helium suppliers switched to 20% air mix around 2015.
It is highly unlikely there are any 98% balloon helium left.
Of course, if you have 20% air, you will not mess yourself up,
but you will not achieve your intended purpose either.

 

[GerMann]

Only a relink

 

[color_me_gone]

@GerMann
Thanks for that!

 

[Elek]

If I use a $30 regulator like this instead of MDB's $300 regulator how much pressure is needed at its output?

 

[crova]

If I use a $30 regulator like this instead of MDB's $300 regulator how much pressure is needed at its output?

I rember someone here is a welder. I hope he could help with converting bars to lpm.
My advice is if you could spend another $30 and get one with proper 'lpm' flow meter,
like this one:

 

[crova]

@Elek @GerMann @Arak
using any kind of sealed chamber filled with pure inert gas is NOT going to work for the following reason:

Even though you inhale pure inert gas, you continue to exhale CO2 until your death.
Residual O2 in the bloodstream and body cells continue the metabolism process.
CO2 is a byproduct of that metabolism.
The sealed chamber will eventually become severely contaminated with CO2 mixed with the inert gas.
This CO2 will be re-inhaled, and returned to the bloodstream.
Buildup of CO2 in the bloodstream will trigger the hypercapnic alarm of the body's self defense mechanism.
Even while unconscious, it will cause the body to struggle severely to get O2,
which will probably result in the involuntary destruction of your setup.

Continuous flow of inert gas is absolutely necessary to purge exhaled CO2 out the bottom of the bag.
Masks are not recommended. The diver has high quality equipment, and knew what he was doing.
I was looking into a respirator mask. @TiredHorse recommended against it,
Just too complicated and fraught with possible malfunctions.
While it would be nice to achieve this method without a bag over your head, the risks of failure are not worth it.

This is my method, and I have studied it considerably.

Great post, @color_me_gone
I too think the proper gas flow within a bag to flush away exhaled CO2 is the most important for this technique.

 

[color_me_gone]

Thanks @crova.
That hade me baffled for a while.
I couldn't understand why a person could continue to exhale CO2 if they were inhaling pure N2.
With a little googling, I found the answer.

You are correct, the airflow is important. Everyone recommends 15 l/m.

 

[Boochky]

Hi all,

I can't afford the MDB setup (and it says you have to be 50). I don't know which regulator to get or how to use it.

How do you get the PPeH? I can find older editions, but I'm not 50 like you have to be to buy it online.

I can get the nitrogen. I just don't understand how to use the regulator or how to attach tubing.

Any help appreciated.

Thanks!

 

[onewayroad]

@Elek @GerMann @Arak
using any kind of sealed chamber filled with pure inert gas is NOT going to work for the following reason:

Even though you inhale pure inert gas, you continue to exhale CO2 until your death.
Residual O2 in the bloodstream and body cells continue the metabolism process.
CO2 is a byproduct of that metabolism.
The sealed chamber will eventually become severely contaminated with CO2 mixed with the inert gas.
This CO2 will be re-inhaled, and returned to the bloodstream.
Buildup of CO2 in the bloodstream will trigger the hypercapnic alarm of the body's self defense mechanism.
Even while unconscious, it will cause the body to struggle severely to get O2,
which will probably result in the involuntary destruction of your setup.

Continuous flow of inert gas is absolutely necessary to purge exhaled CO2 out the bottom of the bag.
Masks are not recommended. The diver has high quality equipment, and knew what he was doing.
I was looking into a respirator mask. @TiredHorse recommended against it,
Just too complicated and fraught with possible malfunctions.
While it would be nice to achieve this method without a bag over your head, the risks of failure are not worth it.

This is my method, and I have studied it considerably.

Yeah, you have to be careful with a mask because it's crucial that 1) the mask can be strapped on tightly and seal so no air can get in and 2) that the mask has a one way valve to let gas out near the mouth.

I didn't think of these things when I bought my cheap mask on ebay but luckily it ticks both boxes. I don't think a respirator would work but I'm not sure.

 

[Hush Sweet Charlotte]

I wonder if anyone can help - if there's anyone who has done a trial run with the nitrogen filling up the bag while it's on top of your head.

I tried this to get a feel for how quickly the bag would fill up and it took such a long time, although I adjusted the flow to almost 25 litres / minute. I was expecting the bag to become quite taunt, so then I would know that's when you pull it over your head, but it never did. The bag isn't too big and doesn't have leaks, nor does my equipment. Is this just what is meant to happen - the bag doesn't become taut because some of the gas is escaping through the head band? How do you know when to pull it down?

I'm so scared I won't be able to do this and have wasted far more gas than I thought I would. Any help welcome!

 

[color_me_gone]

Any help welcome!

I wish I could help you, but I don't even have my gas yet.
I have to wait till wife goes out of town for a couple weeks.
I could never explain away a 40 cuft tank of nitrogen!
The part you are at bothers me too.
@TiredHorse is the expert here, but he is MIA as of late, not ctb, but snowstorm knocked him out badly.

 

[Hush Sweet Charlotte]

Thanks color me gone. I'm wondering if it didn't help the bag was 50 microns thick and heavier than an oven roasting bag, though not sure why that would make a difference really.

 

[color_me_gone]

didn't help the bag was 50 microns thick

Yeah, I think that would be it.
The openness at the bottom, means almost no pressure buildup inside the bag.
The nitrogen is escaping out the bottom, without filling the bag.
Would it be possible to tighten the bottom of the bag around your forehead until the bag fills.
I seriously doubt you could pop the bag doing that, as long as the bottom is not taped.
Once the bag is filled (and expanded), then you could release the band.
Then pull the bag down to your neck. (Speaking speculatively here, of course)

 

[Hush Sweet Charlotte]

Would the weight of the bag have made a difference though? I guess it must have been the gas escaping through the headband though it didn't feel loose. Feel like I'd need to test this again before actually trying to ctb, but I've probably got about 1000 litres of gas left, which sounds like a lot but I have an illness that can affect lung function so I was planning on running the gas at a higher flow rate and for it to maybe take longer than usual.

 

[color_me_gone]

Would the weight of the bag have made a difference though?

I think it would. After all, your can feel it yourself that it is not so flexible, right?

 

[Hush Sweet Charlotte]

Yes, I suppose it means there are more gaps when the elastic is pulled tight and the plastic's gathered together right enough...