Anyone slinging/sidemounting ST72s?

mempilot · 12th December 2007, 19:53

Quote: (Originally Posted by netmage)

Eric, you guys are killing me. Did none of my DIR mindset rub off over the last 2 years of diving w/ you guys....?

I guess GUE taught you to swim off at blazing speed away from your buddies?

Ahhh, the new CCR owner that hasn't gotten wet with it yet is the groups self-proclaimed master, but soon to become the padawan??

And, how come you didn't bring up your reservations about this in private while I was rebuilding your DSV the other night? Public spankings! Jeesh!

I'm mad at you now. Speak to the hand. No really, speak to the haaaannnnndddddd.....

Quote: (Originally Posted by netmage)

Steel tanks will permanently impact your weighting, especially if your going to be carrying for the duration of the dive, a la ocean diving...

Actually, steel tank. See the above configuration. For very deep, AL80 would be in order. The single steel would be used as a replacement for one of the AL40's. Also, the AL80, if carried, would still require weight to be carried, or it would create a bouyant situation soon after cracking it. I call bullshit on this statement.

Quote: (Originally Posted by netmage)

Unless your looking at ditching weight carried elsewhere, your going to be compounding the dynamic instability of your rig... At depth you'll be needing to compensate by inflating your wing furthur...

Buddy, look at your statement. You have to carry ditchable weight to 'use' the AL80. The same principle applies for having to inflate your wing at depth. The 4 to 5 lbs in increased mass from the steel is identical to the 4 to 5 lbs of increased mass needed in ditchable weights in a pocket.

Quote: (Originally Posted by netmage)

According to the good folks over at Huron Scuba (who IMHO have one of the best cylinder spec charts), the faber 72 will swing from -8.5 -> -3.7, whereas the traditional AL80 swings from -1.4 to 4.4...

Check your swing figures. Which is the greater delta? And to make it worse and quote your dynamic stability issue, the AL goes from neg to significantly positive during usage.

Quote: (Originally Posted by netmage)

What about your AL40/80's are you not liking...?

I like that setup, but it is overkill on the Hydro and other similiar wrecks in the area. The capacity and size of an AL80 is not needed, but an AL40 is not enough. You either have to go big, have a 3 person bailout strategy, or don't go. Right now, we go big, since only a 2 person bailout strategy is available most of the time. IMHO, going past reliance on one other person is too much risk. I'm OK with single buddy reliance in most cases, but not beyond that.

mempilot · 12th December 2007, 20:13

Quote: (Originally Posted by netmage)

If one didn't know we are friends, they might think we're sparring...

I'd win.

Quote: (Originally Posted by netmage)

Throw in the 1.5-2lbs for the regulator, and that 4.4lbs shrinks....

Eyeballs installed....check; Eyesight turned on....check; Brain completed selftest....check; Now read the following:

*Empty weights do not include valves (except Pressed Steel and OMS), which would add 1.5 - 2.5 lbs, but buoyancy figures do.

Quote: (Originally Posted by netmage)

From a practical standpoint, diving my AL80 doubles I am weighted perfectly... Carrying multiple aluminum deco bottles through the course of the dive has had negligible impact on my buoyancy.

Nuff said.

Quote: (Originally Posted by netmage)

Since we're talking a bailout scenario, you have two fundamental situations in front of you... your either on a fixed line attached to the wreck, to which you can hang on the line.... or your drifting under a bag on deco, drain the bottle and send it up....

Uhhhh...an AL80 goes positive right after you start sucking on it...heh heh...sending it up the line does nothing for solving anything other than getting rid of a tank...uhhhh...eh eh....now you have the extra weight but the bouyancy is gone....eh eh...

Quote: (Originally Posted by netmage)

The key item I think to drive home here is that these bottles are dynamic, they are not fixed to your rig, as such you need to be able to maintain buoyancy w/o them, should you need to ditch at some point.... The characteristics of steel impose a far greater dynamic shift than aluminum.

If I ditch an AL80, I have to ditch the associated shot too in order to have a balanced rig. If I ditch a ST, that's it; I'm balanced. The term dynamic here has nothing to do with it. Dynamic refers to something causing a variable shift. Your ditching scenario is fixed for both tank with the exception of the added shot to be dropped with the AL80. The variable shift which causes problems comes with consumption from the AL tank; that my friend is dynamic.

***ScubaDadMiami*** · 12th December 2007, 20:26

You have to be prepared for and consider a few different things.

You need to be in a position to be able to remove your bottles while maintaining neutral bouyancy. If you are using a steel, you will have a pretty strong change if you drop a bottle. If you have weighted yourself to be neutral without the bottle, you can still stop yourself from a bolt to the surface, but you will then have to deal with moving quickly to vent and adjust gas for bouyancy all while some other big event is going on that caused you to have to drop the bottle in the first place. Another aspect of weighting yourself to be neutral without the bottle is that it also means that you are going to be quite negative when carrying a full cylinder and having to carry a fair amount of gas in your wing to compensate, which causes streamlining issues.

Yes, you will have a fair amount of swing with an aluminum with gases other than helium. However, with a fair amount of helium in it, the bottle starts to float even when full. So, there won't be a big swing when you remove your bottle. (Since you are now diving deeper, chances are you are going to have some helium in the 80. So, it lessens the impact.) As you drain gas from the 80, you are also draining helium. So too will you eliminate part of what will make the bottle positive. End result: not so much of a bouyancy shift as you might otherwise think.

You need to be able to trade bottles with other divers will staying neutral. If you drop a steel while making a less than perfect pass, see above for what will happen. If you are trading with others that are not using identical bottles, you will still have large shifts and a lot of work to do in order to manage things. Oh, and see how much fun it is trying to maintain trim while holding a steel bottle with one arm extended in front of you after you unclip it and hold it out to make a bottle exchange (especially in a nice, silty low flow cave).

**nigelh** · 12th December 2007, 21:24

Quote: (Originally Posted by ScubaDadMiami)

As you drain gas from the 80, you are also draining helium. So too will you eliminate part of what will make the bottle positive.

Um...
You might want to think about that one.

mempilot · 12th December 2007, 21:40

Quote: (Originally Posted by ScubaDadMiami)

You need to be in a position to be able to remove your bottles while maintaining neutral bouyancy.

Assume you weight your actual Rebreather to be able to maintain neutral or slightly negative bouyancy without bailout, deco, or stage bottles (ie. net bouyancy is negative including anything non-ditchable; exposure protection, body, etc..).

Now look at the bailout bottle and assume you carry 4lbs on the belt for the AL tank:

AL80 Full is: -1.4 lbs + -4 lbs shot (total = -5.4 lbs)
ST66 Full is: -5.15 + 0 lbs shot (total = -5.15 lbs)

The ST66 is less negative, all be it minor in difference, than the AL80.

Now, drop the the tank:

AL80 dropped: Bouyancy change is 1.4 lbs
ST66 dropped: Bouyancy change is 5.15 lbs

The reason for the smaller shift in bouyancy with the AL tank is the fact that you didn't ditch the 4 lb shot.

If you are dropping the tank during an emergency, then you would need to also get rid of the extra 4lbs of shot to equal getting rid of the ST tank (no big deal)

If you are passing the tank without the shot, it is assumed the receiver needs to use the gas. You have passed a bouyancy problem to the stressed diver. The only way to alleviate this extra bouyancy would be to pass the 4lbs of shot with the tank. This would indicate a better place to store the 4lbs would be on the tank itself. Now, you have created the same bouyancy as the ST tank.

Get my drift?

Quote: (Originally Posted by ScubaDadMiami)

If you are using a steel, you will have a pretty strong change if you drop a bottle. If you have weighted yourself to be neutral without the bottle, you can still stop yourself from a bolt to the surface, but you will then have to deal with moving quickly to vent and adjust gas for bouyancy all while some other big event is going on that caused you to have to drop the bottle in the first place. Another aspect of weighting yourself to be neutral without the bottle is that it also means that you are going to be quite negative when carrying a full cylinder and having to carry a fair amount of gas in your wing to compensate, which causes streamlining issues.

This is why the difference between the need to pass the bottle vs. ditching it needs to be addressed for this discussion.

When ditching, you need bouyancy. The AL bottle is already borderline possitive, so the real weight to target is the 4lbs of shot. Ditching an AL tank that is only -1.4 full doesn't buy you a whole lot until the extra shot is chucked with it. Ditching the ST gives you the immediate 5 or so lbs of bouyancy back. The need to ditch comes from loss of bouyancy lift from a failed wing or improper lift/mass planning. Getting rid of only 1.4lbs is not going to make much of a difference, and won't get your rig neutral until you get rid of the 4lbs.

The other ditching scenario is that which you are on the surface, and you are losing bouyancy (ie. no more gas to feed the wing). Having a 4 lb bigger swing at the surface is not an issue.

Now, ditching/staging a bottle in a cave is the real reason to carry AL instead of ST, and for the sake of this discussion, it is irrelevent. I'm not talking about using ST in the caves.

Quote: (Originally Posted by ScubaDadMiami)

Yes, you will have a fair amount of swing with an aluminum with gases other than helium. However, with a fair amount of helium in it, the bottle starts to float even when full. So, there won't be a big swing when you remove your bottle. (Since you are now diving deeper, chances are you are going to have some helium in the 80. So, it lessens the impact.) As you drain gas from the 80, you are also draining helium. So too will you eliminate part of what will make the bottle positive. End result: not so much of a bouyancy shift as you might otherwise think.

The only point to make is this: An AL80 empty is an AL80 empty, no matter what gas occupied it.

In other words, once you've breathed the gas and it is near empty, it is still a very positive piece of metal.

Quote: (Originally Posted by ScubaDadMiami)

You need to be able to trade bottles with other divers will staying neutral. If you drop a steel while making a less than perfect pass, see above for what will happen. If you are trading with others that are not using identical bottles, you will still have large shifts and a lot of work to do in order to manage things.

This is probably the best argument point I've heard for carrying the AL80 vs the ST66/72 while it is full. This statement has made up my mind to abandon the Steels. The rest of the reasons are fairly loose.

Thanks Howard.

Mark Chase · 12th December 2007, 21:51

Quote: (Originally Posted by netmage)

Eric, you guys are killing me. Did none of my DIR mindset rub off over the last 2 years of diving w/ you guys....?

Steel tanks will permanently impact your weighting, especially if your going to be carrying for the duration of the dive, a la ocean diving... Unless your looking at ditching weight carried elsewhere, your going to be compounding the dynamic instability of your rig... At depth you'll be needing to compensate by inflating your wing furthur... According to the good folks over at Huron Scuba (who IMHO have one of the best cylinder spec charts), the Faber 72 will swing from -8.5 -> -3.7, whereas the traditional AL80 swings from -1.4 to 4.4...

What about your AL40/80's are you not liking...?

Like I mentioned Sunday, I'll be shipping 2 or 3 from Cincy over the holidays... they might need a hydro and tumble, but I'll likely sell 2 and keep one as a large oxygen bottle for visits to the caves or as a booster supply for trips.

-Tim

Tim can you help, My tanks are all broken

The steel one with 250 bar in floats and the Ali one with 230 bar in sinks like a rock

My Ali 80 with no valve on it in fresh water weighs 1.8KG neg

can you fix it

Hear a steel 7ltr with 100 bar of 32% in appears to float in fresh water where as one with 230 bar 80% in sinks. Surely those terribly heavy steel tanks cant only be negative by the weight of 100bar of gas??

Look its definitely broken it appears to be floating in fresh water????

ATB

Mark

netmage · 12th December 2007, 22:29

And kid's... that's why we don't use metric... <g>

What are those? 45cuft?

Mark Chase · 12th December 2007, 23:01

Quote: (Originally Posted by netmage)

And kid's... that's why we don't use metric... <g>

What are those? 45cuft?

Ali 80 is 11.5ltrs

Ali 40 is 5.25ltrs

The small ones in the pic are 7s so whats that? 54ft?

The big yellow one is a 10 so 77ft?

Both light weight Faber Steel tanks

The big white one is a standard Ali 80

ATB

Mark

Mark Chase · 12th December 2007, 23:07

The main thing i like about steel is how compact they are.

The Ali 80 on the left has 2587 ltrs of gas in @ 225 bar The Steel on the right has 2500ltrs coz i can blow it up to 250bar without any serious concerns.

Gobfish1 · 12th December 2007, 23:41

Quote: (Originally Posted by netmage)

And kid's... that's why we don't use metric... <g>

What are those? 45cuft?

well kids looks like it floats or it dont ....

Kids

12th December 2007, 19:53	#11 (permalink)
mempilot Eric Stadtmueller Current Rebreather/s: Megalodon Other Rebreather/s: Megalodon Join Date: Aug 2006 Location: Ft. Lauderdale Posts: 1,445	Re: Anyone slinging/sidemounting ST72s? Quote: (Originally Posted by netmage) Eric, you guys are killing me. Did none of my DIR mindset rub off over the last 2 years of diving w/ you guys....? I guess GUE taught you to swim off at blazing speed away from your buddies? Ahhh, the new CCR owner that hasn't gotten wet with it yet is the groups self-proclaimed master, but soon to become the padawan?? And, how come you didn't bring up your reservations about this in private while I was rebuilding your DSV the other night? Public spankings! Jeesh! I'm mad at you now. Speak to the hand. No really, speak to the haaaannnnndddddd..... Quote: (Originally Posted by netmage) Steel tanks will permanently impact your weighting, especially if your going to be carrying for the duration of the dive, a la ocean diving... Actually, steel tank. See the above configuration. For very deep, AL80 would be in order. The single steel would be used as a replacement for one of the AL40's. Also, the AL80, if carried, would still require weight to be carried, or it would create a bouyant situation soon after cracking it. I call bullshit on this statement. Quote: (Originally Posted by netmage) Unless your looking at ditching weight carried elsewhere, your going to be compounding the dynamic instability of your rig... At depth you'll be needing to compensate by inflating your wing furthur... Buddy, look at your statement. You have to carry ditchable weight to 'use' the AL80. The same principle applies for having to inflate your wing at depth. The 4 to 5 lbs in increased mass from the steel is identical to the 4 to 5 lbs of increased mass needed in ditchable weights in a pocket. Quote: (Originally Posted by netmage) According to the good folks over at Huron Scuba (who IMHO have one of the best cylinder spec charts), the faber 72 will swing from -8.5 -> -3.7, whereas the traditional AL80 swings from -1.4 to 4.4... Check your swing figures. Which is the greater delta? And to make it worse and quote your dynamic stability issue, the AL goes from neg to significantly positive during usage. Quote: (Originally Posted by netmage) What about your AL40/80's are you not liking...? I like that setup, but it is overkill on the Hydro and other similiar wrecks in the area. The capacity and size of an AL80 is not needed, but an AL40 is not enough. You either have to go big, have a 3 person bailout strategy, or don't go. Right now, we go big, since only a 2 person bailout strategy is available most of the time. IMHO, going past reliance on one other person is too much risk. I'm OK with single buddy reliance in most cases, but not beyond that. __________________ Eric Stadtmueller, otherwise known as, MEM "Da Pilot"
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12th December 2007, 20:13	#12 (permalink)
mempilot Eric Stadtmueller Current Rebreather/s: Megalodon Other Rebreather/s: Megalodon Join Date: Aug 2006 Location: Ft. Lauderdale Posts: 1,445	Re: Anyone slinging/sidemounting ST72s? Quote: (Originally Posted by netmage) If one didn't know we are friends, they might think we're sparring... I'd win. Quote: (Originally Posted by netmage) Throw in the 1.5-2lbs for the regulator, and that 4.4lbs shrinks.... Eyeballs installed....check; Eyesight turned on....check; Brain completed selftest....check; Now read the following: Empty weights do not include valves (except Pressed Steel and OMS), which would add 1.5 - 2.5 lbs, but buoyancy figures do. Quote:* (Originally Posted by netmage) From a practical standpoint, diving my AL80 doubles I am weighted perfectly... Carrying multiple aluminum deco bottles through the course of the dive has had negligible impact on my buoyancy. Nuff said. Quote: (Originally Posted by netmage) Since we're talking a bailout scenario, you have two fundamental situations in front of you... your either on a fixed line attached to the wreck, to which you can hang on the line.... or your drifting under a bag on deco, drain the bottle and send it up.... Uhhhh...an AL80 goes positive right after you start sucking on it...heh heh...sending it up the line does nothing for solving anything other than getting rid of a tank...uhhhh...eh eh....now you have the extra weight but the bouyancy is gone....eh eh... Quote: (Originally Posted by netmage) The key item I think to drive home here is that these bottles are dynamic, they are not fixed to your rig, as such you need to be able to maintain buoyancy w/o them, should you need to ditch at some point.... The characteristics of steel impose a far greater dynamic shift than aluminum. If I ditch an AL80, I have to ditch the associated shot too in order to have a balanced rig. If I ditch a ST, that's it; I'm balanced. The term dynamic here has nothing to do with it. Dynamic refers to something causing a variable shift. Your ditching scenario is fixed for both tank with the exception of the added shot to be dropped with the AL80. The variable shift which causes problems comes with consumption from the AL tank; that my friend is dynamic. __________________ Eric Stadtmueller, otherwise known as, MEM "Da Pilot"
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12th December 2007, 20:26	#13 (permalink)
*ScubaDadMiami* Moderator Current Rebreather/s: Optima Other Rebreather/s: Join Date: Sep 2005 Location: Florida, USA Posts: 2,138	Re: Anyone slinging/sidemounting ST72s? You have to be prepared for and consider a few different things. You need to be in a position to be able to remove your bottles while maintaining neutral bouyancy. If you are using a steel, you will have a pretty strong change if you drop a bottle. If you have weighted yourself to be neutral without the bottle, you can still stop yourself from a bolt to the surface, but you will then have to deal with moving quickly to vent and adjust gas for bouyancy all while some other big event is going on that caused you to have to drop the bottle in the first place. Another aspect of weighting yourself to be neutral without the bottle is that it also means that you are going to be quite negative when carrying a full cylinder and having to carry a fair amount of gas in your wing to compensate, which causes streamlining issues. Yes, you will have a fair amount of swing with an aluminum with gases other than helium. However, with a fair amount of helium in it, the bottle starts to float even when full. So, there won't be a big swing when you remove your bottle. (Since you are now diving deeper, chances are you are going to have some helium in the 80. So, it lessens the impact.) As you drain gas from the 80, you are also draining helium. So too will you eliminate part of what will make the bottle positive. End result: not so much of a bouyancy shift as you might otherwise think. You need to be able to trade bottles with other divers will staying neutral. If you drop a steel while making a less than perfect pass, see above for what will happen. If you are trading with others that are not using identical bottles, you will still have large shifts and a lot of work to do in order to manage things. Oh, and see how much fun it is trying to maintain trim while holding a steel bottle with one arm extended in front of you after you unclip it and hold it out to make a bottle exchange (especially in a nice, silty low flow cave). __________________ Howard Packer IANTD CCR Instructor Miami Beach, Florida CCRDiveTraining.com Last edited by ScubaDadMiami : 12th December 2007 at 20:30.
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12th December 2007, 21:24	#14 (permalink)
nigelh New Member Current Rebreather/s: Inspiration Vision Other CCR Other Rebreather/s: Inspiration Classic Other CCR Join Date: Mar 2005 Location: Brighton, Sussex, UK Posts: 836	Re: Anyone slinging/sidemounting ST72s? Quote: (Originally Posted by ScubaDadMiami) As you drain gas from the 80, you are also draining helium. So too will you eliminate part of what will make the bottle positive. Um... You might want to think about that one. __________________ nigelh
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12th December 2007, 21:40	#15 (permalink)
mempilot Eric Stadtmueller Current Rebreather/s: Megalodon Other Rebreather/s: Megalodon Join Date: Aug 2006 Location: Ft. Lauderdale Posts: 1,445	Re: Anyone slinging/sidemounting ST72s? Quote: (Originally Posted by ScubaDadMiami) You need to be in a position to be able to remove your bottles while maintaining neutral bouyancy. Assume you weight your actual Rebreather to be able to maintain neutral or slightly negative bouyancy without bailout, deco, or stage bottles (ie. net bouyancy is negative including anything non-ditchable; exposure protection, body, etc..). Now look at the bailout bottle and assume you carry 4lbs on the belt for the AL tank: AL80 Full is: -1.4 lbs + -4 lbs shot (total = -5.4 lbs) ST66 Full is: -5.15 + 0 lbs shot (total = -5.15 lbs) The ST66 is less negative, all be it minor in difference, than the AL80. Now, drop the the tank: AL80 dropped: Bouyancy change is 1.4 lbs ST66 dropped: Bouyancy change is 5.15 lbs The reason for the smaller shift in bouyancy with the AL tank is the fact that you didn't ditch the 4 lb shot. If you are dropping the tank during an emergency, then you would need to also get rid of the extra 4lbs of shot to equal getting rid of the ST tank (no big deal) If you are passing the tank without the shot, it is assumed the receiver needs to use the gas. You have passed a bouyancy problem to the stressed diver. The only way to alleviate this extra bouyancy would be to pass the 4lbs of shot with the tank. This would indicate a better place to store the 4lbs would be on the tank itself. Now, you have created the same bouyancy as the ST tank. Get my drift? Quote: (Originally Posted by ScubaDadMiami) If you are using a steel, you will have a pretty strong change if you drop a bottle. If you have weighted yourself to be neutral without the bottle, you can still stop yourself from a bolt to the surface, but you will then have to deal with moving quickly to vent and adjust gas for bouyancy all while some other big event is going on that caused you to have to drop the bottle in the first place. Another aspect of weighting yourself to be neutral without the bottle is that it also means that you are going to be quite negative when carrying a full cylinder and having to carry a fair amount of gas in your wing to compensate, which causes streamlining issues. This is why the difference between the need to pass the bottle vs. ditching it needs to be addressed for this discussion. When ditching, you need bouyancy. The AL bottle is already borderline possitive, so the real weight to target is the 4lbs of shot. Ditching an AL tank that is only -1.4 full doesn't buy you a whole lot until the extra shot is chucked with it. Ditching the ST gives you the immediate 5 or so lbs of bouyancy back. The need to ditch comes from loss of bouyancy lift from a failed wing or improper lift/mass planning. Getting rid of only 1.4lbs is not going to make much of a difference, and won't get your rig neutral until you get rid of the 4lbs. The other ditching scenario is that which you are on the surface, and you are losing bouyancy (ie. no more gas to feed the wing). Having a 4 lb bigger swing at the surface is not an issue. Now, ditching/staging a bottle in a cave is the real reason to carry AL instead of ST, and for the sake of this discussion, it is irrelevent. I'm not talking about using ST in the caves. Quote: (Originally Posted by ScubaDadMiami) Yes, you will have a fair amount of swing with an aluminum with gases other than helium. However, with a fair amount of helium in it, the bottle starts to float even when full. So, there won't be a big swing when you remove your bottle. (Since you are now diving deeper, chances are you are going to have some helium in the 80. So, it lessens the impact.) As you drain gas from the 80, you are also draining helium. So too will you eliminate part of what will make the bottle positive. End result: not so much of a bouyancy shift as you might otherwise think. The only point to make is this: An AL80 empty is an AL80 empty, no matter what gas occupied it. In other words, once you've breathed the gas and it is near empty, it is still a very positive piece of metal. Quote: (Originally Posted by ScubaDadMiami) You need to be able to trade bottles with other divers will staying neutral. If you drop a steel while making a less than perfect pass, see above for what will happen. If you are trading with others that are not using identical bottles, you will still have large shifts and a lot of work to do in order to manage things. This is probably the best argument point I've heard for carrying the AL80 vs the ST66/72 while it is full. This statement has made up my mind to abandon the Steels. The rest of the reasons are fairly loose. Thanks Howard. __________________ Eric Stadtmueller, otherwise known as, MEM "Da Pilot"
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12th December 2007, 21:51	#16 (permalink)
Mark Chase I go down for ages Current Rebreather/s: Classic Kiss Other Rebreather/s: Inspiration Classic Join Date: Jan 2005 Location: Kent Posts: 2,694	Re: Anyone slinging/sidemounting ST72s? Quote: (Originally Posted by netmage) Eric, you guys are killing me. Did none of my DIR mindset rub off over the last 2 years of diving w/ you guys....? Steel tanks will permanently impact your weighting, especially if your going to be carrying for the duration of the dive, a la ocean diving... Unless your looking at ditching weight carried elsewhere, your going to be compounding the dynamic instability of your rig... At depth you'll be needing to compensate by inflating your wing furthur... According to the good folks over at Huron Scuba (who IMHO have one of the best cylinder spec charts), the Faber 72 will swing from -8.5 -> -3.7, whereas the traditional AL80 swings from -1.4 to 4.4... What about your AL40/80's are you not liking...? Like I mentioned Sunday, I'll be shipping 2 or 3 from Cincy over the holidays... they might need a hydro and tumble, but I'll likely sell 2 and keep one as a large oxygen bottle for visits to the caves or as a booster supply for trips. -Tim Tim can you help, My tanks are all broken The steel one with 250 bar in floats and the Ali one with 230 bar in sinks like a rock My Ali 80 with no valve on it in fresh water weighs 1.8KG neg can you fix it Hear a steel 7ltr with 100 bar of 32% in appears to float in fresh water where as one with 230 bar 80% in sinks. Surely those terribly heavy steel tanks cant only be negative by the weight of 100bar of gas?? Look its definitely broken it appears to be floating in fresh water???? ATB Mark __________________ Is it supposed to make that noise ? I took my unit to the dive shop and demanded they bolt on every thing that would fit. Join my elite diving teem and get a Tshirt "Doing It Chasey"Hammerhead Eccr Advanced Diving System Last edited by Mark Chase : 12th December 2007 at 23:03.
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12th December 2007, 22:29	#17 (permalink)
netmage Tim Owens Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Dec 2005 Location: Coconut Creek, FL Posts: 512	Re: Anyone slinging/sidemounting ST72s? And kid's... that's why we don't use metric... <g> What are those? 45cuft?
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12th December 2007, 23:01	#18 (permalink)
Mark Chase I go down for ages Current Rebreather/s: Classic Kiss Other Rebreather/s: Inspiration Classic Join Date: Jan 2005 Location: Kent Posts: 2,694	Re: Anyone slinging/sidemounting ST72s? Quote: (Originally Posted by netmage) And kid's... that's why we don't use metric... <g> What are those? 45cuft? Ali 80 is 11.5ltrs Ali 40 is 5.25ltrs The small ones in the pic are 7s so whats that? 54ft? The big yellow one is a 10 so 77ft? Both light weight Faber Steel tanks The big white one is a standard Ali 80 ATB Mark __________________ Is it supposed to make that noise ? I took my unit to the dive shop and demanded they bolt on every thing that would fit. Join my elite diving teem and get a Tshirt "Doing It Chasey"Hammerhead Eccr Advanced Diving System
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12th December 2007, 23:07	#19 (permalink)
Mark Chase I go down for ages Current Rebreather/s: Classic Kiss Other Rebreather/s: Inspiration Classic Join Date: Jan 2005 Location: Kent Posts: 2,694	Re: Anyone slinging/sidemounting ST72s? The main thing i like about steel is how compact they are. The Ali 80 on the left has 2587 ltrs of gas in @ 225 bar The Steel on the right has 2500ltrs coz i can blow it up to 250bar without any serious concerns. __________________ Is it supposed to make that noise ? I took my unit to the dive shop and demanded they bolt on every thing that would fit. Join my elite diving teem and get a Tshirt "Doing It Chasey"Hammerhead Eccr Advanced Diving System
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12th December 2007, 23:41	#20 (permalink)
Gobfish1 Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Classic Inspiration Vision Evolution Join Date: Apr 2005 Location: Manchester UK Posts: 371	Re: Anyone slinging/sidemounting ST72s? Quote: (Originally Posted by netmage) And kid's... that's why we don't use metric... <g> What are those? 45cuft? well kids looks like it floats or it dont .... Kids __________________ Steve G Apparently not the only gay diver in the village http://drinkingliberally.org/blogs/o...nzee-glock.gif http://www.scubatunes.com/audio/vol01/mp3/HiTech.mp3 Last edited by Gobfish1 : 12th December 2007 at 23:43.
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