oxygen ccr conversions

cstmwrks · 26th November 2006, 20:17

Quote: (Originally Posted by Dave Sutton)

The other thing is to re-purge at about the 30 minute mark, as you will be offgassing nitrogen raidly as you go onto pure 02 and that nitrogen which is expired into the bag can lower the fraqction 02 in the gas so much that it can cause hypoxia on ascent.

Dave

Dave,
You kinda stepped on a fact VS myth question that I have not set up the lab to answer on my own just yet. I remember a very small rant on the subject from Will Smithers ... Anyhow the amount of N2 one might dump back in the loop from your own lungs would be in the range of a few CC's and not Liters as many folks imply. So at some point I'm going to have to take a spin to 20 feet on 02... sit on my arse and see how far down I can drop the PP02 in 30 minutes.
Have you done this?

Bill

**Dave Sutton** · 26th November 2006, 22:35

Quote: (Originally Posted by cstmwrks)

Dave,
You kinda stepped on a fact VS myth question that I have not set up the lab to answer on my own just yet. Have you done this?

Bill

You know....

My experience with isobaric DCS and isobaric counterdiffusion is really aviation oriented, meaning that we pre-breathe pure 02 for 30 mins before any intentional high altitude (low pressure) flights (IE: high altitude unpressurized cabin flights breathing 02). We essentially 'decompress' from our "1 ATMA Saturation State" (IE: The state we live in daily) by breathing pure 02 on the surface for 30 mins to dump nitrogen, prior to breathing pure 02 at say 35,000 where there will be *more* nitrogen coming out of solution. I talked to the flight surgeons about this and they believed that we were dumping in the 0.5 liter range of nitrogen. I'm not sure what their level of confidence in is that figure though. Be interesting to do an empirical test to see what the deal is. Obviously the smaller the counterlung the greater the delta-PP02 will be.

Dave

**Dave Sutton** · 26th November 2006, 22:36

Quote: (Originally Posted by DepthCharge)

Dave,
On the C-96 is the scrubber a radial or axial design? Just see some possible problems with a radial design.

Axial.

Dave

**Dave Sutton** · 26th November 2006, 22:52

Quote: (Originally Posted by Lure_Angler)

I feel, by not purging, the pendulum would be able to emulate a mixed gas CCR system. Thus, the system could be used to dive slightly deeper, say maybe between 10 to 15 meters.

However, because there wouldn't be a diluent tank, there is no way to control ppO2. It would then be very dangerous to bring it to deeper depths like 20 over meters should the ppO2 go haywire. Oxygen toxicity would then result.

If I go along this line of thinking, wouldn't it be safe not to purge instead, since the diluted oxygen in the loop gives a wider safety margin? Assuming we respect the 20 feet limit.

TC

You are on the right track. Here's the deal:

(1): By not fully purging you are not really diving an "02" rebreather any longer, you are diving a mixed gas nitrox rebreather. You re not "emulating" one, you are DIVING one.

(2): As an example, if you did not purge AT ALL and started with only air in the counterlung, and dived soon enough to not drop the PP02 before descent. you would have the maximum available "diluent" in the loop and would have the "02 addition only" rebreather that would allow you to dive the deepest.

(3): On descent, you only add 02 and naturally as you add 02 AND descent, the PP02 is rising rapidly. How high depends on the volume of the counterlung to start with and the end volume you dive the loop at. IE: If you FULLY fill the counterlung at the surface with air but then actually dive it at say 1/2 full, the effective depth is deeper than if you continued to keep it filled to full volume with 02 *only* as you descend.

(4): As Bill Sewall says, there is more than one way to maintain constant PP02 once you establish it. Constant volume/constant bouyancy *at a fixed depth* = constant PP02, as you will add 02 to maintain volume/bouyancy as you metabolize 02 in the loop.

(5): Doing this stuff "blind" (IE: No PP02 monitoring) is Russian Roulette.... do it long enough and you WILL get killed, dig?

(6): Naturally the HIGHEST level of danger is on ascent, where the PP02 is dropping rapidly. A full 02 purge at 20 feet is essential.

(7): These methods are NOT endorsed by ANYONE. Especially not blind flying without PP02 monitoring. Not even *I* do that...

(8): Not purging an 02 rig when diving the rig *intending to dive with 02" is a KILLER. You can easially metabolize the 02 out of the gas, end up with an inspirable bolus of inert gas in the loop, and die either on the bottom or (more likely) on your ascent from 20 feet. PP02 changes VERY rapidly near the surface for any given fraction 02 in the loop. if you INTEND to use the rig as an 02 one, PURGE IT OUT before you dive it, get it? ;-)

I have done the "parlor trick" of carrying a spare-air so I could blow some air into a pure 02 rebreather as I descend to depth to control the PP02 and have *as a demonstration* done so diving 02 rigs to well over 100 feet (*well* over 100 feet...) but I tell you this: It was with PP02 monitoring, and was done as a *stunt*, IE: like a professional stunt-man will *carefully* wreck a car for a movie production. That does *not* mean that it is a viable daily habit. My "smallest mixed gas rig ever" uses a spare-air as the diluent supply cylinder and is an 02 rebreather with PP02 monitoring, and and spare air permanently attached. Using this rig below any depth from which you would not make a swimming free ascent is akin to climbing Mt. Everest without supplemental 02: It is Alpinism to the extreme, and there is ZERO margin for error. NONE. Being a freediver who routinely spearfishes in 60+ feet of water gives me some confidence there, and when I use that rig I am also using my freediving fins, suit, mask, and gear. I don't use it deeper than I am willing to swim back as a freediver.

Like Chuck Yaeger said after spinning the F-104 "Well, it *can* be done, boys, but I don't recommend it...."

Dave

cstmwrks · 26th November 2006, 23:40

Quote: (Originally Posted by Dave Sutton)

You know....

I talked to the flight surgeons about this and they believed that we were dumping in the 0.5 liter range of nitrogen. I'm not sure what their level of confidence in is that figure though. Be interesting to do an empirical test to see what the deal is. Obviously the smaller the counterlung the greater the delta-PP02 will be.

Dave

Hmmm... Well this is why I would question the real volume at least as far as 02 diving is concerned. We have our normoxic 1ata of N2 disolved in our blood. For the gas to move from point A to point B we have to create a vacuum so to speak, or in this case breathing 02 as pure as possible. We are however going under pressure during the dive. As N2 is captured in the bag we are no longer breathing pure 02 and that in of itself will slow down the movement. The closer the equilibrium, the slower the gas movement.
If it was a respectable volume and you were not in a rush to a target depth of say 80 feet one could reason that by mearly hanging out for 10 minutes you could avoid a puff off a bail out tank for your needed volume of N2 to maintain acceptable PP02.
I only know from the lovely story of a Father and Son team that died from blowing off all deco ( wreck of the U-who? ) from something like a 20 minute 200' dive that there was enough gas in suspension to turn all his blood into a froth. Assuming accurate acount of the story as I was not there when they cut the poor kid open.
Bill

**Dave Sutton** · 27th November 2006, 00:31

Quote: (Originally Posted by cstmwrks)

Hmmm... Well this is why I would question the real volume at least as far as 02 diving is concerned. We have our normoxic 1ata of N2 disolved in our blood. For the gas to move from point A to point B we have to create a vacuum so to speak, or in this case breathing 02 as pure as possible. We are however going under pressure during the dive. As N2 is captured in the bag we are no longer breathing pure 02 and that in of itself will slow down the movement. The closer the equilibrium, the slower the gas movement.
If it was a respectable volume and you were not in a rush to a target depth of say 80 feet one could reason that by mearly hanging out for 10 minutes you could avoid a puff off a bail out tank for your needed volume of N2 to maintain acceptable PP02.
I only know from the lovely story of a Father and Son team that died from blowing off all deco ( wreck of the U-who? ) from something like a 20 minute 200' dive that there was enough gas in suspension to turn all his blood into a froth. Assuming accurate acount of the story as I was not there when they cut the poor kid open.
Bill

Hmmm......

I was on scene when a bell-bounce dive off of a semi-submersible drilling rig went wrong and the bell was brought up to the surface open to the atmosphere rather than sealed. The divers had been to about 450 and had been there an hour. They were effervescent. Eyeballs had frank bubbles visible when I went to look for vital signs. One was dead (drowned, had fallen out of the bell with his helmet off, but was still attached to his harness and umbilical and was hanging 50 feet below the bell when it surfaced). Other diver was alive, unconcious, regained conciousness in the deck chamber, but then died there after talking for about 3 minutes. He was recompressed with a certain young Diving Medical Technician to about 250 feet in the deck chamber, got CPR for a half hour, in the 120 degree temp in the chamber due to adiabatic heating on descent, then after the panic was over the med tech was on an unknown depth/time profile due to the shit that was going on and needed to do a saturation decompression with the dead body of his buddy strapped into a sleeping bag and lashed under the chamber bunk for 2 days ("No, we cannot remove any diver from the chamber until he has done his decompression"..... ) Thanks a lot. Been there, done that, thanks once, no thanks again sir someone else next time if you would be so kind sir. And people wonder why I have strong opinions on some of these subjects.

Sorry for the rant.... Paul Akana and Roger Gotoula, friends. Died in the Bay of Campeche, summer of 1980 in the Mark-IV Bell-Bounce system. Seems like yesterday.

The Rouses died on the U-869. Local guys, a boat I used to work on as a mate. Not a good scene from those who were there.

What you posit makes sense, but I think an experiment is in order. Say a 25 foot 02 dive with a known PP02 at the beginning and measurements of PP02 every 5 minutes for an hour ought to suffice. Anyone? I can do it but it'll be a few weeks at earliest.

Dave

cstmwrks · 27th November 2006, 00:32

Quote: (Originally Posted by Dave Sutton)

Like Chuck Yaeger said after spinning the F-104 "Well, it *can* be done, boys, but I don't recommend it...."

Dave

You know I met Chuck Yaeger at a little airport in Alaska around 88 I think. Nice enough fellow for what I got to see of him.

Oh well.. on the 02 subject again. The longest 02 dive I did this year was about 50 minutes. Depth is classified largely because I can not remember that detail. So when I'm out puttering around its just that .. puttering.. no combat swims, no stress and no heavy breathing. I may have at best 1/2 a liter more gas in the bag than I need to fill my lungs. I do not get to go very long before I touch the gas addition button and I do not blow a large load in when I do. Point being at almost an hour the pattern of adding gas never changed.

I'm gonna have to get a meter up and running again... this is getting me to wonder..

cstmwrks · 27th November 2006, 00:41

Quote: (Originally Posted by Dave Sutton)

What you post makes sense, but I think an experiment is in order. Say a 25 foot 02 dive with a known PP02 at the beginning and measurements of PP02 every 5 minutes for an hour ought to suffice. Anyone? I can do it but it'll be a few weeks at earliest.

Dave

OK the race is on.. I kinda hacked apart my one 02 rig that was set up for sensors but will see if I can get it togeather. No point in letting the results of one rule the roost. I'll take a slate and write down the numbers. We can compare the notes and see if they differ or match like we copied notes over some ones shoulder.

Bill

**Dave Sutton** · 27th November 2006, 00:44

Well, let's put an end to this gremlin once and for all. PP02 meter and 02 bag in hand, we can figure it out. First man to do the test gets a free oil-filled pony bottle filled with pure 02 from the other, deal?

OK, now explain *that* inside story to the crowd... I've been been the lector lately, now time for me to be the auctor. What ever happened to that bottle anyhow? (and *this* story should blow the minds of those 02 cleaning freaks once and for all... )

And did you really shoot it with a 7.62mm tracer in the end?

Dave

cstmwrks · 27th November 2006, 02:07

Quote: (Originally Posted by Dave Sutton)

Well, let's put an end to this gremlin once and for all. PP02 meter and 02 bag in hand, we can figure it out. First man to do the test gets a free oil-filled pony bottle filled with pure 02 from the other, deal?

Dave

OK, but I'm not too sure about IATA or CFR49 regulations on packaging and transport of said pony bottle.

OK folks it goes like this. Dave was kind enough to ship me a pony that had seen better days many years ago. I had a 155 02 tank with the valve set up so I could open it by remote control from my Bunker ( yes we get a little carried away up there in Alaska, kinda like when we...ah, never mind ) and also had an armored video camera. No matter how bad it got it would all be on film.
Some machine work for a special valve and we were all set. The only thing special about the valve was a weak, and I do mean weak attempt at flame arresting as I did not want to loose the 155 out of the deal. So add me in the picture doing all the stuff our mothers told us not to do, like adding a lovely sampler of hydrocarbons the likes of which no one in there right mind would ever get in there beloved 02 pony bottles.
So roll camera on three, two, one, valve open............. yup. 8 minutes of the most boring video on earth. The only fun part was me looking at my little bomb and thinking.. you know, 02.. one slight screw up and bang!!
So I have pure 02 rammed in a greased up pony bottle just setting there.
I'm sure to this very day, Dave is proud to have been part of such a boring outcome.

So what came of the 02 / oil filled tank you ask? Dave mentioned tracer
ammo.. Well take your pick:
1. took it out with tracer ammo.
2. Bill unhooked the d#mn thing and went diving with it.
3. Its still there at the Bunker.. why the H#ll do you think I moved to Idaho?
4. Classified.

Great... thanks Dave, now you got me thinking about doing it again.. only better some how..?!?

Bill

26th November 2006, 20:17	#41 (permalink)
cstmwrks The old ways still work. Current Rebreather/s: Home Build Other Rebreather/s: Not Bought Yet Home Build Join Date: Sep 2006 Location: Boise Idaho Posts: 238	Re: oxygen ccr conversions Quote: (Originally Posted by Dave Sutton) The other thing is to re-purge at about the 30 minute mark, as you will be offgassing nitrogen raidly as you go onto pure 02 and that nitrogen which is expired into the bag can lower the fraqction 02 in the gas so much that it can cause hypoxia on ascent. Dave Dave, You kinda stepped on a fact VS myth question that I have not set up the lab to answer on my own just yet. I remember a very small rant on the subject from Will Smithers ... Anyhow the amount of N2 one might dump back in the loop from your own lungs would be in the range of a few CC's and not Liters as many folks imply. So at some point I'm going to have to take a spin to 20 feet on 02... sit on my arse and see how far down I can drop the PP02 in 30 minutes. Have you done this? Bill
(Offline)

26th November 2006, 22:35	#42 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,913	Re: oxygen ccr conversions Quote: (Originally Posted by cstmwrks) Dave, You kinda stepped on a fact VS myth question that I have not set up the lab to answer on my own just yet. Have you done this? Bill You know.... My experience with isobaric DCS and isobaric counterdiffusion is really aviation oriented, meaning that we pre-breathe pure 02 for 30 mins before any intentional high altitude (low pressure) flights (IE: high altitude unpressurized cabin flights breathing 02). We essentially 'decompress' from our "1 ATMA Saturation State" (IE: The state we live in daily) by breathing pure 02 on the surface for 30 mins to dump nitrogen, prior to breathing pure 02 at say 35,000 where there will be more nitrogen coming out of solution. I talked to the flight surgeons about this and they believed that we were dumping in the 0.5 liter range of nitrogen. I'm not sure what their level of confidence in is that figure though. Be interesting to do an empirical test to see what the deal is. Obviously the smaller the counterlung the greater the delta-PP02 will be. Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com
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26th November 2006, 22:36	#43 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,913	Re: oxygen ccr conversions Quote: (Originally Posted by DepthCharge) Dave, On the C-96 is the scrubber a radial or axial design? Just see some possible problems with a radial design. Axial. Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com
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26th November 2006, 22:52	#44 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,913	Re: oxygen ccr conversions Quote: (Originally Posted by Lure_Angler) I feel, by not purging, the pendulum would be able to emulate a mixed gas CCR system. Thus, the system could be used to dive slightly deeper, say maybe between 10 to 15 meters. However, because there wouldn't be a diluent tank, there is no way to control ppO2. It would then be very dangerous to bring it to deeper depths like 20 over meters should the ppO2 go haywire. Oxygen toxicity would then result. If I go along this line of thinking, wouldn't it be safe not to purge instead, since the diluted oxygen in the loop gives a wider safety margin? Assuming we respect the 20 feet limit. TC You are on the right track. Here's the deal: (1): By not fully purging you are not really diving an "02" rebreather any longer, you are diving a mixed gas nitrox rebreather. You re not "emulating" one, you are DIVING one. (2): As an example, if you did not purge AT ALL and started with only air in the counterlung, and dived soon enough to not drop the PP02 before descent. you would have the maximum available "diluent" in the loop and would have the "02 addition only" rebreather that would allow you to dive the deepest. (3): On descent, you only add 02 and naturally as you add 02 AND descent, the PP02 is rising rapidly. How high depends on the volume of the counterlung to start with and the end volume you dive the loop at. IE: If you FULLY fill the counterlung at the surface with air but then actually dive it at say 1/2 full, the effective depth is deeper than if you continued to keep it filled to full volume with 02 only as you descend. (4): As Bill Sewall says, there is more than one way to maintain constant PP02 once you establish it. Constant volume/constant bouyancy at a fixed depth = constant PP02, as you will add 02 to maintain volume/bouyancy as you metabolize 02 in the loop. (5): Doing this stuff "blind" (IE: No PP02 monitoring) is Russian Roulette.... do it long enough and you WILL get killed, dig? (6): Naturally the HIGHEST level of danger is on ascent, where the PP02 is dropping rapidly. A full 02 purge at 20 feet is essential. (7): These methods are NOT endorsed by ANYONE. Especially not blind flying without PP02 monitoring. Not even I do that... (8): Not purging an 02 rig when diving the rig intending to dive with 02" is a KILLER. You can easially metabolize the 02 out of the gas, end up with an inspirable bolus of inert gas in the loop, and die either on the bottom or (more likely) on your ascent from 20 feet. PP02 changes VERY rapidly near the surface for any given fraction 02 in the loop. if you INTEND to use the rig as an 02 one, PURGE IT OUT before you dive it, get it? ;-) I have done the "parlor trick" of carrying a spare-air so I could blow some air into a pure 02 rebreather as I descend to depth to control the PP02 and have as a demonstration* done so diving 02 rigs to well over 100 feet (well over 100 feet...) but I tell you this: It was with PP02 monitoring, and was done as a stunt, IE: like a professional stunt-man will carefully wreck a car for a movie production. That does not mean that it is a viable daily habit. My "smallest mixed gas rig ever" uses a spare-air as the diluent supply cylinder and is an 02 rebreather with PP02 monitoring, and and spare air permanently attached. Using this rig below any depth from which you would not make a swimming free ascent is akin to climbing Mt. Everest without supplemental 02: It is Alpinism to the extreme, and there is ZERO margin for error. NONE. Being a freediver who routinely spearfishes in 60+ feet of water gives me some confidence there, and when I use that rig I am also using my freediving fins, suit, mask, and gear. I don't use it deeper than I am willing to swim back as a freediver. Like Chuck Yaeger said after spinning the F-104 "Well, it can be done, boys, but I don't recommend it...." Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com Last edited by Dave Sutton : 26th November 2006 at 22:58.
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26th November 2006, 23:40	#45 (permalink)
cstmwrks The old ways still work. Current Rebreather/s: Home Build Other Rebreather/s: Not Bought Yet Home Build Join Date: Sep 2006 Location: Boise Idaho Posts: 238	Re: oxygen ccr conversions Quote: (Originally Posted by Dave Sutton) You know.... I talked to the flight surgeons about this and they believed that we were dumping in the 0.5 liter range of nitrogen. I'm not sure what their level of confidence in is that figure though. Be interesting to do an empirical test to see what the deal is. Obviously the smaller the counterlung the greater the delta-PP02 will be. Dave Hmmm... Well this is why I would question the real volume at least as far as 02 diving is concerned. We have our normoxic 1ata of N2 disolved in our blood. For the gas to move from point A to point B we have to create a vacuum so to speak, or in this case breathing 02 as pure as possible. We are however going under pressure during the dive. As N2 is captured in the bag we are no longer breathing pure 02 and that in of itself will slow down the movement. The closer the equilibrium, the slower the gas movement. If it was a respectable volume and you were not in a rush to a target depth of say 80 feet one could reason that by mearly hanging out for 10 minutes you could avoid a puff off a bail out tank for your needed volume of N2 to maintain acceptable PP02. I only know from the lovely story of a Father and Son team that died from blowing off all deco ( wreck of the U-who? ) from something like a 20 minute 200' dive that there was enough gas in suspension to turn all his blood into a froth. Assuming accurate acount of the story as I was not there when they cut the poor kid open. Bill
(Offline)

27th November 2006, 00:31	#46 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,913	Re: oxygen ccr conversions Quote: (Originally Posted by cstmwrks) Hmmm... Well this is why I would question the real volume at least as far as 02 diving is concerned. We have our normoxic 1ata of N2 disolved in our blood. For the gas to move from point A to point B we have to create a vacuum so to speak, or in this case breathing 02 as pure as possible. We are however going under pressure during the dive. As N2 is captured in the bag we are no longer breathing pure 02 and that in of itself will slow down the movement. The closer the equilibrium, the slower the gas movement. If it was a respectable volume and you were not in a rush to a target depth of say 80 feet one could reason that by mearly hanging out for 10 minutes you could avoid a puff off a bail out tank for your needed volume of N2 to maintain acceptable PP02. I only know from the lovely story of a Father and Son team that died from blowing off all deco ( wreck of the U-who? ) from something like a 20 minute 200' dive that there was enough gas in suspension to turn all his blood into a froth. Assuming accurate acount of the story as I was not there when they cut the poor kid open. Bill Hmmm...... I was on scene when a bell-bounce dive off of a semi-submersible drilling rig went wrong and the bell was brought up to the surface open to the atmosphere rather than sealed. The divers had been to about 450 and had been there an hour. They were effervescent. Eyeballs had frank bubbles visible when I went to look for vital signs. One was dead (drowned, had fallen out of the bell with his helmet off, but was still attached to his harness and umbilical and was hanging 50 feet below the bell when it surfaced). Other diver was alive, unconcious, regained conciousness in the deck chamber, but then died there after talking for about 3 minutes. He was recompressed with a certain young Diving Medical Technician to about 250 feet in the deck chamber, got CPR for a half hour, in the 120 degree temp in the chamber due to adiabatic heating on descent, then after the panic was over the med tech was on an unknown depth/time profile due to the shit that was going on and needed to do a saturation decompression with the dead body of his buddy strapped into a sleeping bag and lashed under the chamber bunk for 2 days ("No, we cannot remove any diver from the chamber until he has done his decompression"..... ) Thanks a lot. Been there, done that, thanks once, no thanks again sir someone else next time if you would be so kind sir. And people wonder why I have strong opinions on some of these subjects. Sorry for the rant.... Paul Akana and Roger Gotoula, friends. Died in the Bay of Campeche, summer of 1980 in the Mark-IV Bell-Bounce system. Seems like yesterday. The Rouses died on the U-869. Local guys, a boat I used to work on as a mate. Not a good scene from those who were there. What you posit makes sense, but I think an experiment is in order. Say a 25 foot 02 dive with a known PP02 at the beginning and measurements of PP02 every 5 minutes for an hour ought to suffice. Anyone? I can do it but it'll be a few weeks at earliest. Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com
(Offline)

27th November 2006, 00:32	#47 (permalink)
cstmwrks The old ways still work. Current Rebreather/s: Home Build Other Rebreather/s: Not Bought Yet Home Build Join Date: Sep 2006 Location: Boise Idaho Posts: 238	Re: oxygen ccr conversions Quote: (Originally Posted by Dave Sutton) Like Chuck Yaeger said after spinning the F-104 "Well, it can be done, boys, but I don't recommend it...." Dave You know I met Chuck Yaeger at a little airport in Alaska around 88 I think. Nice enough fellow for what I got to see of him. Oh well.. on the 02 subject again. The longest 02 dive I did this year was about 50 minutes. Depth is classified largely because I can not remember that detail. So when I'm out puttering around its just that .. puttering.. no combat swims, no stress and no heavy breathing. I may have at best 1/2 a liter more gas in the bag than I need to fill my lungs. I do not get to go very long before I touch the gas addition button and I do not blow a large load in when I do. Point being at almost an hour the pattern of adding gas never changed. I'm gonna have to get a meter up and running again... this is getting me to wonder..
(Offline)

27th November 2006, 00:41	#48 (permalink)
cstmwrks The old ways still work. Current Rebreather/s: Home Build Other Rebreather/s: Not Bought Yet Home Build Join Date: Sep 2006 Location: Boise Idaho Posts: 238	Re: oxygen ccr conversions Quote: (Originally Posted by Dave Sutton) What you post makes sense, but I think an experiment is in order. Say a 25 foot 02 dive with a known PP02 at the beginning and measurements of PP02 every 5 minutes for an hour ought to suffice. Anyone? I can do it but it'll be a few weeks at earliest. Dave OK the race is on.. I kinda hacked apart my one 02 rig that was set up for sensors but will see if I can get it togeather. No point in letting the results of one rule the roost. I'll take a slate and write down the numbers. We can compare the notes and see if they differ or match like we copied notes over some ones shoulder. Bill
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27th November 2006, 00:44	#49 (permalink)
Dave Sutton Diveshop of Horrors Current Rebreather/s: Sport Kiss MK 15.X rEvo Other CCR Azimuth Home Build Other Rebreather/s: Evolution Megalodon rEvo Other CCR Azimuth Home Build Join Date: Jun 2006 Location: Narragansett, Rhode Island and Hackettstown, New Jersey Posts: 2,913	Re: oxygen ccr conversions Well, let's put an end to this gremlin once and for all. PP02 meter and 02 bag in hand, we can figure it out. First man to do the test gets a free oil-filled pony bottle filled with pure 02 from the other, deal? OK, now explain that inside story to the crowd... I've been been the lector lately, now time for me to be the auctor. What ever happened to that bottle anyhow? (and this story should blow the minds of those 02 cleaning freaks once and for all... ) And did you really shoot it with a 7.62mm tracer in the end? Dave __________________ "Silent Diving with No Bubbles and No Politics".... www.nobubblediving.com Last edited by Dave Sutton : 27th November 2006 at 00:47.
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27th November 2006, 02:07	#50 (permalink)
cstmwrks The old ways still work. Current Rebreather/s: Home Build Other Rebreather/s: Not Bought Yet Home Build Join Date: Sep 2006 Location: Boise Idaho Posts: 238	Re: oxygen ccr conversions Quote: (Originally Posted by Dave Sutton) Well, let's put an end to this gremlin once and for all. PP02 meter and 02 bag in hand, we can figure it out. First man to do the test gets a free oil-filled pony bottle filled with pure 02 from the other, deal? Dave OK, but I'm not too sure about IATA or CFR49 regulations on packaging and transport of said pony bottle. OK folks it goes like this. Dave was kind enough to ship me a pony that had seen better days many years ago. I had a 155 02 tank with the valve set up so I could open it by remote control from my Bunker ( yes we get a little carried away up there in Alaska, kinda like when we...ah, never mind ) and also had an armored video camera. No matter how bad it got it would all be on film. Some machine work for a special valve and we were all set. The only thing special about the valve was a weak, and I do mean weak attempt at flame arresting as I did not want to loose the 155 out of the deal. So add me in the picture doing all the stuff our mothers told us not to do, like adding a lovely sampler of hydrocarbons the likes of which no one in there right mind would ever get in there beloved 02 pony bottles. So roll camera on three, two, one, valve open............. yup. 8 minutes of the most boring video on earth. The only fun part was me looking at my little bomb and thinking.. you know, 02.. one slight screw up and bang!! So I have pure 02 rammed in a greased up pony bottle just setting there. I'm sure to this very day, Dave is proud to have been part of such a boring outcome. So what came of the 02 / oil filled tank you ask? Dave mentioned tracer ammo.. Well take your pick: 1. took it out with tracer ammo. 2. Bill unhooked the d#mn thing and went diving with it. 3. Its still there at the Bunker.. why the H#ll do you think I moved to Idaho? 4. Classified. Great... thanks Dave, now you got me thinking about doing it again.. only better some how..?!? Bill
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