Deco bottle SPG

[Jason B]

Make sure you O2 clean your mask as well...I hate to see you exhale through your nose and inadvertently blow your head off.

LOL...got a good laugh and it made me think for a minute. The human body takes in oxygen and puts carbon dioxide, isn't that correct.

Jason

 

[JeffG]

LOL...got a good laugh and it made me think for a minute. The human body takes in oxygen and puts carbon dioxide, isn't that correct.

Jason

Yep...but the O2 will still be over 40% for the exhale of 100% O2...oh...and your regs are no longer O2 clean when they come into contact with air (ie 1 sec after your done O2 cleaning it)...let alone contact with water (and that goo that floats around in the water).

 

[Atticus]

[Answer to original question]

The gauge you have will work just fine so long as it is clean. If it is not clean then I would purchase a clean brass & glass gauge and call it done. Supporting Gators gauge cleaning hobby sounds pretty good too

I have not heard an argument in favor of plastic gauges (due to weight or otherwise). I use metal gauges and expect a long life out of them.

I would not consider using a full length hose on a deco bottle SPG. This becomes increasingly scary when you consider 2 or more deco bottles and the difficulty associating a particular gauge with a particular bottle.

If you're considering a full length SPG hose due to a lack of a short one PM me and I'll send you one free.


[Thread hijack banter]

The issue with O2 cleanliness has to do with the total pressure of oxygen exposed to the fuel (reg, mask, whatever).

A deco regulator first stage and pressure gauge will commonly be exposed to 150 atm of oxygen pressure (ie: 2200 psi tank pressure). You'll want to have them clean and made with oxygen compatible materials.

A mask will be exposed to what you're breathing. Hopefully this is LESS than 1.6 ppO2. I don't know about you guys, but I'm NOT breathing oxygen at 200 fsw...

A regulator second stage is going to see something in the ball park of 150 psi on the supply side, or about 10 atm. Not a huge deal, but I wouldn't flush my hoses with motor oil

Jeff is correct when he says that you exhale a significant portion of the oxygen you inhale. The oxygen in, CO2 out comment is not applicable in that we only metabolize a small amount of oxygen in each breath, particularly on rich mixes. Consider the operation of an SCR rebreather (ie: Drager Dolphin) and why it extends your gas supply.

 

[Padipro]

I second the opinion on the brass and glass SPG. Deco bottles get banged around quite a bit and a plastic one is just to easy to break. You break it during the dive and the bottle is worthless until it's replaced.

I don't know where it was that you read only use a plastic SPG but that's exactly the oppsite of everything I've ever read.

If you want to get one cheap take a look on Ebay. I've bought several nice ones that have worked great. But IMO ditch the plastic and get a brass one.

 

[Jason B]

I don't know where I read about plastic....I've been googling it like crazy and can't find anything to the such. I must have dreamed it. I'll just order me another brass dive rite with the 6" hose already on it and be done with it. I wasn't trying to be cheap, I just had the gauge already laying around and thought I could put it to use.
Thanks for the help.

Jason

 

[Rick Murchison]

For a deco bottle, I just use a peanut gauge, which reduces the failure points to a minimum and gives me all the information I need. Any old gauge will do.
Rick

 

[Padipro]

Hay Jason I know exactly what you mean. I had a couple of US Divers Micra regs laying around and wanted to use them for my deco regs. I had one hell of a time getting people to except the fact that they would work just fine. People kept telling me that I didn't need a balanced first stage for a deco reg and that I should just buy another cheap unbalanced reg instead. I kept telling them that I already had these two regs and that I never used them and asked why should I spend another $300 to buy two new regs when I already had these two. I finally got them to admit that there was no reason that they wouldn't work it was just over kill as a balanced reg wasn't necessary. Now I have two O2 clean regs for my deco bottles and didn't have to spend more then $50 to get them cleaned.

 

[MaxBottomtime]

A plastic spg is OK. You want your deco bottles to be slightly buoyant.

 

[kramynot2000]

I'd suggest a brass and glass SPG for durability. When I started putting stuff together for a deco bottle I used a plastic SPG that I had lying around as well. But as some have mentioned, the bottles do get banged around. My plastic guage lasted less than a year before a leak developed.

 

[DA Aquamaster]

For a deco bottle, I just use a peanut gauge, which reduces the failure points to a minimum and gives me all the information I need. Any old gauge will do.
Rick

I agree with Rick on this one. I am a relatively recent button gauge convert. They are low profile, less prone to snagging, are virtually indestructable and they also eliminate two o-rings in the HP spool and a potentially leaky HP hose.

And they are inexpensive at $25-$35 each - about 1/3 the cost of a good brass SPG.

They are not quite as easy to read under water, but then you don't need to read them that often and when think you may need to, you are hanging on a deco line with nothing better to do anyway. They are really of more value on the surface to double check the pressure before the dive as you either are going to plan properly and have enough or you won't. If you screw it up and run short, having a gauge tell you you're screwed won't make it any better.