Method Exit bag and inert gas megathread

[outrider567]

Does anyone know what the failure rate is? I'm hoping failures are just due to faulty equipment/insufficient gas

As per Greenberg, the failure rate is zero

 

[Falling Slowly]

Have you looked into full face scuba mask connected to pure nitrogen tank? I am trying to find people with knowledge on if this is a good method. It would allow you to breath in pure nitrogen while exhaling CO2 out of the mask so there is no build up of CO2. I'm wondering if this method would be better because you could see clearly until you pass out and there would be no CO2 buildup whatsoever.

Go back over the thread, plenty has been said about the use of a scuba mask. The use of a SCBA(self contained breathing apparatus), i.e. not an underwater SCUBA setup, seems the more popular option.

There are other more expert posters on the issue here, but from having a quick look back over old posts, it seems SCUBA masks can either be positive pressure or negative pressure masks; and you need a positive pressure mask to be certain no exterior air getting into the mask (I could be corrected on this).

Anyway, it seems pretty much everyone who has gone down the self contained breathing apparatus route has gone for SCBA as opposed to SCUBA.
Here are some examples: here and here

 

[NoFutureAnymore]

So I finally managed to test the purity of my N2 cilinder which should have a quality of 4.6 (->99,996%) according the supplier.
I used the CY-12C (it's mentioned many times and an oxygen meter doesn't kill, so I guess it's allowed) for testing, but it doesn't seem accurate.
I followed the procedure from PPeH two times and the first time it read 0,8% and the second time 0,5%. It also fluctuates heavily when you use the balloon to pump normal air around. I don't have much reason to not trust the source of the N2 because they sell in almost every city in 1-2 stores. So I'm either doing something wrong or the meter doesn't work well. @Das Nichts: how did it work out for you?

So I got a new meter and now it reads 0,07%, which means that the quality is higher then 99,8%. This meter is also more stable, so it was indeed a malfunctioning meter. I'm now waiting for the rest of the SCUBA equipement and then I'll do a blackout test.

 

[outrider567]

As per Greenberg, the failure rate is zero with EEBD hood or proper exit bag

So I got a new meter and now it reads 0,07%, which means that the quality is higher then 99,8%. This meter is also more stable, so it was indeed a malfunctioning meter. I'm now waiting for the rest of the SCUBA equipement and then I'll do a blackout test.

Can't get better than 99.8% purity

 

[puffnstuff]

So I did a test run with the EB method and nitrogen. Everything went well but about a minute in I felt like I was sufficating and had to remove the bag. Any advice on what I might be doing wrong?

 

[anonaon]

So I did a test run with the EB method and nitrogen. Everything went well but about a minute in I felt like I was sufficating and had to remove the bag. Any advice on what I might be doing wrong?

Most likely an excess amount of CO2 inside the bag. What flowrate did u use? How tight was the neck gap? Did you hyperventilate an expel your lungs before taking your first breath of N2?

 

[k1w1]

Greetings : To others using the EEBD hood I did a dry test and need to ask those of you in the same position if the hood's moulded mouth/nosepeice needs to be sitting snugly against my face. Being glued into the hood, there exists some clearance between the edges of the moulded breathing mechanism & the contours of my face. It crossed my mind to use a wide elastic strap pulled over the outside the hood to hold it close. Having said this the hood fills & collapses very effectively with regular inhalation/exhalation so there is snug fit round the neck & the hood is clearly well designed for the job. Best to everyone & please chime in on this issue of fit.

 

[anonaon]

Greetings : To others using the EEBD hood I did a dry test and need to ask those of you in the same position if the hood's moulded mouth/nosepeice needs to be sitting snugly against my face. Being glued into the hood, there exists some clearance between the edges of the moulded breathing mechanism & the contours of my face. It crossed my mind to use a wide elastic strap pulled over the outside the hood to hold it close. Having said this the hood fills & collapses very effectively with regular inhalation/exhalation so there is snug fit round the neck & the hood is clearly well designed for the job. Best to everyone & please chime in on this issue of fit.

Mine's like that as well. I dont think it matters otherwise manufacturers of EEBD hoods wouldve gotten sued left and right for not having the "perfect" fit.

I found that if I lie down and pull the top of the hood slightly down, it covers my nose/mouth region without any substantial gaps

 

[k1w1]

Mine's like that as well. I dont think it matters otherwise manufacturers of EEBD hoods wouldve gotten sued left and right for not having the "perfect" fit.

Thanks mate, I was hoping to get your input.

 

[x0nSS]

If you're not sure about your hood,do what Vizzy did,this is the best way to increase your confidence in the setup.

Did read that. Will order parts.

Greetings : To others using the EEBD hood I did a dry test and need to ask those of you in the same position if the hood's moulded mouth/nosepeice needs to be sitting snugly against my face. Being glued into the hood, there exists some clearance between the edges of the moulded breathing mechanism & the contours of my face. It crossed my mind to use a wide elastic strap pulled over the outside the hood to hold it close. Having said this the hood fills & collapses very effectively with regular inhalation/exhalation so there is snug fit round the neck & the hood is clearly well designed for the job. Best to everyone & please chime in on this issue of fit.

Am using yellow EEBD hood. Have been using hood alone to try and can say the same. Hood fills and closes as I breathe while plugging hose. Waiting on air meter to test because Im not sure of this kind of science haha.
When I put on hood I put mouthpiece on then move hood around for better fitting. I guess works because clear part doesn't fog up from breath.

 

[Willthishelp?]

- prefill the hood by turning on the gas and holding it atop your head

- Soap-water spray is probably the best way to check for leaks but also listen for any hissing sounds and look for a drop in the pressure gauge of the regulator at 0lpm flowrate

- if you buy from a reputable source then its not necessary to check for purity but you must check for leaks regardless

Cant find oil free soap as vizzy suggested do you think that's nescesarry? Or any dishwasher soap is okay?

 

[anonaon]

Cant find oil free soap as vizzy suggested do you think that's nescesarry? Or any dishwasher soap is okay?

Not sure about dishwasher soap but it has to be oil/grease free (to prevent damage to the regulator). Or you can just buy gas leak detection spray like this one

 

[puffnstuff]

Most likely an excess amount of CO2 inside the bag. What flowrate did u use? How tight was the neck gap? Did you hyperventilate an expel your lungs before taking your first breath of N2?

15 LPM and the bag is not too tight but maybe I did not hyperventilate enough. Thanks, I will try again.

 

[anonaon]

15 LPM and the bag is not too tight but maybe I did not hyperventilate enough. Thanks, I will try again.

Might also be a good idea to test for co2 using a meter. They're pretty cheap on amazon

 

[ClownWorld2023]

Might also be a good idea to test for co2 using a meter. They're pretty cheap on amazon

I looked around for CO2 meters when I bought my oxygen meter, and I found them to be really expensive.
The cheapest ones started around $400-500.

I also looked for much cheaper CO2 meters, similar to the one Vizzy showed in his thread, but would they be accurate at all?

 

[lion4000b]

Gasmonkey has helped me a lot but looks like he is having a well deserved break. Just want to summarise my steps and get some feedback:

Im using the SCBA system:

Confirm cylinder size and quantity (10l bottle is ample)
Confrim gas is pure (reputable retailers assurance is sufficient)
Confirm gas pressure
Sit down upright in a chair and strap your body. Be secure so that you won't fall over when black out. Do not lie down. A few final twitches are possible but convulsions are unlikely.
Put the mask on. Check to make sure its properly sealed.
Open the cylinder's valve.
Take a deep breath of air and hold your breath.
Insert the demand valve into the mask.
Hold breath and Pre-fill mask (pressing the front black button for 1 second). It pumps at 400 LPM when pressed full. If you press longer gas will simply flow through the mask escaping through the exhalation valve.
Insert wrists into the straps/ropes (not really necessary)
Exhale as completely as possible and empty your lungs
Take a deep breath of Nitrogen. Relax and breathe slowly, calmly and deeply. A lot of people don't notice anything, they just black out, but symptoms may include tingling in my hands, dizziness and disorientation (perhaps like a sports concussion), gray visions around the edges.
With SCBA you breathe a guaranteed 100% pure gas from the get-go with absolutely zero air/oxygen, the time to lose consciousness will be under 20 second with death to follow within 5-10 minutes.

 

[Falling Slowly]

Gasmonkey has helped me a lot but looks like he is having a well deserved break. Just want to summarise my steps and get some feedback:

Im using the SCBA system:

Confirm cylinder size and quantity (10l bottle is ample)
Confrim gas is pure (reputable retailers assurance is sufficient)
Confirm gas pressure
Sit down upright in a chair and strap your body. Be secure so that you won't fall over when black out. Do not lie down. A few final twitches are possible but convulsions are unlikely.
Put the mask on. Check to make sure its properly sealed.
Open the cylinder's valve.
Take a deep breath of air and hold your breath.
Insert the demand valve into the mask.
Hold breath and Pre-fill mask (pressing the front black button for 1 second). It pumps at 400 LPM when pressed full. If you press longer gas will simply flow through the mask escaping through the exhalation valve.
Insert wrists into the straps/ropes (not really necessary)
Exhale as completely as possible and empty your lungs
Take a deep breath of Nitrogen. Relax and breathe slowly, calmly and deeply. A lot of people don't notice anything, they just black out, but symptoms may include tingling in my hands, dizziness and disorientation (perhaps like a sports concussion), gray visions around the edges.
With SCBA you breathe a guaranteed 100% pure gas from the get-go with absolutely zero air/oxygen, the time to lose consciousness will be under 20 second with death to follow within 5-10 minutes.

I'm not going with this method, have rescue hood setup, but it seems you've got everything covered. I don't think I'll bother checking the O2 levels of the cylinder either, will take the reputable retailer at their word also. If you're ctb soon, good luck!

 

[Willthishelp?]

- prefill the hood by turning on the gas and holding it atop your head

- Soap-water spray is probably the best way to check for leaks but also listen for any hissing sounds and look for a drop in the pressure gauge of the regulator at 0lpm flowrate

- if you buy from a reputable source then its not necessary to check for purity but you must check for leaks regardless

Can I use dishwasher soap to check leaks on nitrogen tank?

 

[DeadHead]

Edit: According to the gas consumption I estimate, that I breathed Nitrogen for one minute or one and a half minute.

That's quite long, I mean it's quite a few breaths. It would be useful to know how many breaths to expect before passing out.

 

[x0nSS]

Can I use dishwasher soap to check leaks on nitrogen tank?

If you can blow bubbles with it then it will work.

 

[DeadHead]

Thats only for exit bags. Methods thay have exhale valves (EEBD,SCBA,SCUBA) can be done lying down

Why can't you lie down with exit bag?

 

[x0nSS]

Why can't you lie down with exit bag?

gravity

 

[Willthishelp?]

If you can blow bubbles with it then it will work.

I heard it won't work with nitrogen don't know why

 

[ztem]

I'm now waiting for the rest of the SCUBA equipement and then I'll do a blackout test.

I think you will have jacrispy's problem.That reg is DIN300 and you need the same adapter that we use for the SCBA setup.If you look at the pic,almost half of the regulator's thread is outside the adapter but looks like you can use a DIN300 reg with the DIN200(200-200 G5/8 to W24.32) adapter according to these people:

Connect the regulator to your adapter then open the cylinder and check if you can hear a hissing sound like this.

After that do a high pressure leak test,open the cylinder valve slowly and fully to fully pressurize the connection and after 10sec,close the cylinder valve and watch the pressure gauge for 10 minutes and If the pressure drop is more than 10bar,there is definitely a leak.

You can also check for leaks like this.

 

[x0nSS]

I heard it won't work with nitrogen don't know why

Ignore me then. Im not good with Science

 

[NoFutureAnymore]

I think you will have jacrispy's problem.That reg is DIN300 and you need the same adapter that we use for the SCBA setup.If you look at the pic,almost half of the regulator's thread is outside the adapter but looks like you can use a DIN300 reg with the DIN200(200-200 G5/8 to W24.32) adapter according to these people:

Did @jacrispy have a leakage then? I find it really confusing and makes me a little bit nervous. So, if a SCUBA DIN300 regulator fits on a DIN200 adapter, why doesn't a SCBA regulator fit into the DIN200 adapter?

 

[ztem]

Did @jacrispy have a leakage then?

He said I haven't even opened the cylinder yet.

I find it really confusing and makes me a little bit nervous

So, if a SCUBA DIN300 regulator fits on a DIN200 adapter, why doesn't a SCBA regulator fit into the DIN200 adapter?

I think it will fit but this will happen.

 

[NoFutureAnymore]

I think it will fit but this will happen.

Why do you think that will be a problem? I also used a flow restrictor to measure the quality and it also sticked out and I didn't hear any leaking during the testing. The seal sits at the top, so the seal still presses against the bottle. It also makes sense. A 300 bar regulator in a 200 bar cilinder doesn't lead to a dangerous situation, but a 200 bar regulator on a 300 bar cilinder does. So I guess it needs more thread to withstand the higher pressure.

 

[ztem]

I also used a flow restrictor to measure the quality and it also sticked out and I didn't hear any leaking during the testing

So if you have no problem with that adapter, that adapter will be the next solution for the SCBA setup.
There's also a DIN300 G5/8 to CGA-580 adapter in the US.

 

[Falling Slowly]

GasMonkey reported a successful CTB with an EEBD Hood and only 15 LPM, and just a 580 Liter Nitrogen gas tank---Also, read Greenberg's posts on the EEBD Hood and flow rate on this thread, I think pages 40 to 60(Do not read anything from a poster named FromGermany, who spread false info)

EEBD hood is as reliable as it gets--Das Nichts is the only poster here that has passed out, nothing was uncomfortable but he added he saw red and green lights

I stand corrected, but my point stands, the poster named FromGermany was full of shit.

Just looking back at some of those older posts that you referred to. While that FromGermany guy seemed ignorant and arrogant, he claims he tested a few EEBD hoods and seemed convinced the EEBD method wasn't worth the risk. Seems to think the hoods won't be filled fast enough or continuous enough with the inert gas.

Also seemed convinced that at least 20lpm was needed. He might have come across as a bit of an asshole, but did he have any reason to bullshit people?

As someone with EEBD setup, it puts a little bit of doubt in my head.