TL;DR: Failed ctb attempt, party tanks, no regulator, reclining on bed, oven bag, plastic tubes.
Hello to all fellow sufferers. A few days ago I tried to ctb with the helium method, but without using the usual gas flow regulator.
As you can tell, this has been a failure.
Here's what happened:
1. Prepared two tanks, ~13.5 liters, ~320 liters of compressed helium each, so ~640 liters total. Seller's claimed that the purity is 99.9+, but I did not test it myself. Tubes attached right to the outlets of tanks.
One of the tank had been bought recently, and the other around 2 years ago. I had let the gas on the older tank run (for testing purposes) for some while, but not long; after that, I had closed it properly (or at least I think so) and stored it in a proper place until now.
2. Prepared a bag: 40x45cm (15.75"x17.72"), elastic tied around the neck part, plastic tubes from helium tanks taped to the inside of the bag. Found no leaks when testing. I did the elastic according to instruction ("snug but not tight"), but I can't be sure I did it correctly.
3. Positioned myself on bed, reclining at around 60° on pillows (half-lying, half-sitting, like in a car seat pulled back). Made sure to not get the tubes stuck between arms and body, and practiced pulling the bag from head to neck.
4. Wore the bag like a swimming cap, scrunched all the air out, and turned the valves on tanks to enable helium flow.
5. When the bag was almost full (~30-60 seconds later), I started hyperventilating, and after a while I finally exhaled deeply, pulled the bag over my head, checked the elastic tightness (not breathing in yet), and only then started taking deep breaths.
6. Nothing was happening even after 20-40 seconds. I noticed that the flow was too weak (I easily could "inhale" a wall of the bag, which, to my understanding, shouldn't happen). Because of that, I turned off the gas in panic, ripped the bag off my head, and proceeded to the next attempt.
7. This time I tried with a higher gas flow rate. When I did all the preparations and pulled the bag to my neck, I noticed that I did not "inhale" the oven bag wall this time. I thought that everything will be over soon, and just laid back, breathing deeply. But there were no effect: even after ~40+ seconds I haven't passed out. I started getting curious about leaks through holes, helium purity and proper adjusting of elastic band on my neck, but there was nothing to worry about as I've checked all these things beforehand (of course, assuming that I comprehended everything correctly, and the helium vendor did not lie about purity of gas).
8. But from this point on I cannot recollect what had happened. I lost my memory of what happened next: I think I just turned off the valves after ~2mins of being stuck in pure helium environment, but this is impossible.
9. I woke up 40-60 minutes later, my head inside the bag (if I even remember correctly... these memories are very hazy). Tried to turn off the valves, but was surprised because the valve on a newer tank wasn't even opened, and the older tank was exhausted completely. I felt very sleepy/dizzy, my lower legs/calves hurt, and even standing upright was a very hard task.
So, my version of what had happened is: I did pass out on the second try, but in a half-unconscious manner I turned only the one valve off (on the newer tank), while the second tank was continuing to transmit gas at desired speed. This tank exhausted too fast to kill me, possibly because of the small leaks (the tank is 2 years old), or too much experimenting.
I can't feel any brain damage in terms of vision blur, memory shortage, or something like that. Also I felt no SI at all, not physiologically (CO2 buildup), not psychologically (so I was brave that day).
On a positive note: I did pass out successfully, so the helium is pure!
But still there are concerns: I don't know if the helium is pure in the newer tank because it was turned off when I woke up, so it must've been the older tank which knocked me unconscious. But I want to try again, and so I would have to buy a new tank, and so I can't know if the helium would be pure in this. And obviously regulator would help immensely.
Please comment on this. What did I do wrong? If I had to guess, then I'd say that this half-conscious state ruined everything. What do you think? I very much want to know the opinion of more knowledgeable forum members. If you are so kind to answer, please start with assuming that I can't have access to regulator, and then go from there. Thank you.
Additional notes: I did read the PPH, watch the Dignified dying video (with the two party tanks and no regulator), looked at the herman photos (with 15 different helium ctbs), and skimmed through Megathread (covered around 60-70%). Is this knowledge enough? Do I have to research further? If so, what would you recommend?
Also, are today's party helium tanks the same as they were, say, 15 years ago? Same pressure, volume, flow speed? So, could a tutorial written 15 years ago in Switzerland/US be applicable to today's situation in Eastern EU?
Please forgive me for this barrage of questions, I really want to know what was wrong.
P.S.: included pics of my setup, hope this is enough. The photographed tank is the newer one, but the older is entirely identical (in the appearance at least, can't be sure about gas purity though)
