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RBEmerson · 19-08-2009, 07:10

Quote:

Originally Posted by jkd

This is not good. Compressors for industrial use will most likley be pumping oil vapor into your lungs.

John

Too right!!! This is another sample of "what you don't know can hurt you". Depth (i.e., associated air pressure increase) potentiates effects from contaminants in the air supply. To say nothing of the problems of inhaling oil spray, even at sea level pressure.

Therapy · 19-08-2009, 16:10

OK, I get it.

So put it up for me.

With a 30 ft hose off of a hookah or down with a scuba tank, the down time at 30 ft is exactly the same?

**Tellie** · 19-08-2009, 16:32

Quote:

Originally Posted by Therapy

OK, I get it.

So put it up for me.

With a 30 ft hose off of a hookah or down with a scuba tank, the down time at 30 ft is exactly the same?

Yes.

It's volume and pressure. If you blow up a ballon with air at the surface and take it down thirty feet underwater it will be under twice the pressure it was at the surface and be half the size it was at the surface. Same thing happens to your lungs when you hold your breath and dive 30 feet. If at thirty feet you fill that ballon with more air you can make it the same size as it was at the surface but it will have twice the amount of air in it as it did at the surface. As you know if you tied the ballon off and let it rise to the surface it would burst. Same thing with your lungs. How you fill your lungs up at thirty feet doesn't make a difference, be it tank or Hookah. So the same rules apply.

Captain Bill · 19-08-2009, 16:45

The issue is that a lung is not as tough as the balloon and a healthy lung will pop just coming up 4 feet. If you have any scar tissue on your lungs or any type of obstructive pulmonary problem it could be even less.

Knowazark · 19-08-2009, 16:59

Quote:

I use this.

As silly as it may sound, a device like that (if such a device existed) would have the serious potential to kill you due to carbon dioxide poisoning. Your exhalations would be insufficient to push your expired air out of the snorkel and CO2 levels would rise until there was insufficient O2 in the inhalent air to support body function.

I know it was a joke, but even something as simple as that can get you killed.

Therapy · 19-08-2009, 17:01

Quote:

Originally Posted by Tellie

Yes.

It's volume and pressure.

And time.

got it.

Therapy · 19-08-2009, 17:08

Quote:

Originally Posted by Knowazark

As silly as it may sound, a device like that (if such a device existed) would have the serious potential to kill you due to carbon dioxide poisoning. Your exhalations would be insufficient to push your expired air out of the snorkel and CO2 levels would rise until there was insufficient O2 in the inhalent air to support body function.

I know it was a joke, but even something as simple as that can get you killed.

No it can't.

I always have to jump in when the argument of high CO2 levels come up as a way to kill someone who is conscious. It does not happen. Rising CO2 levels stimulate the body to breath. Breathing becomes more rapid and deep. As the blood CO2 levels rise the person begins to become agitated and panic ensues. A conscious person would abandon that "breathing stick" and fight for the surface long before the chance of unconsciousness is reached.

**Tellie** · 19-08-2009, 17:44

Quote:

Originally Posted by Knowazark

As silly as it may sound, a device like that (if such a device existed) would have the serious potential to kill you due to carbon dioxide poisoning. Your exhalations would be insufficient to push your expired air out of the snorkel and CO2 levels would rise until there was insufficient O2 in the inhalent air to support body function.

I know it was a joke, but even something as simple as that can get you killed.

Actually if you tried to use this it just simply wouldn't work. You'd exhale once and that would be it. You'd never be able to inhale.

**Tellie** · 19-08-2009, 17:49

Quote:

Originally Posted by Therapy

And time.

got it.

Hey Therapy get your boat to some clear water over there and I'll hop on over with my Hookah and teach you how to use it to clean your bottom. Uh....your boats bottom.

Therapy · 19-08-2009, 18:49

Quote:

Originally Posted by Tellie

Hey Therapy get your boat to some clear water over there and I'll hop on over with my Hookah and teach you how to use it to clean your bottom. Uh....your boats bottom.

Cool!

I am in clear water just past the marina entrance.

RBEmerson · 19-08-2009, 19:27

Quote:

Originally Posted by Therapy

OK, I get it.

So put it up for me.

With a 30 ft hose off of a hookah or down with a scuba tank, the down time at 30 ft is exactly the same?

If you're asking "how long can I stay down", in one sense, the answer is "as long as you have air". The problem is coming back up. Air is basically a mix of nitrogen and oxygen. We need oxygen to stay alive (although diving pure oxygen becomes lethal below, IIRC, 30+ feet). The nitrogen in air doesn't do a lot for us but it's still there. The body absorbs it under pressure, with soft tissues taking it up quickly and harder tissues (i.e., bone) taking it up slowly. Come up before unloading the added nitrogen load and it's possible to likely the nitrogen, when the pressure is released, will form bubbles in the joints (painful!), under the skin (you become living bubble wrap - not good), in the blood (the bubbles can block blood flow - embolisms can be fatal or at least cause serious trauma), and also along nerves (nerve damage is hard to recover from). While various authorities vary on the maximum bottom time allowed to stay at "only" 30 feet, the limit is somewhere between 200 and 300 minutes. Past that, decompression stops (to unload nitrogen through breathing it off) are mandatory.

The temptation is to say "200 minutes?!? My air only lasts about 60 minutes, so no worry." Except that even when staying inside the "no deco" time, there is still some risk. Which is why a three minute deco stop at 15 feet is now common practice.

Also, keep in mind that nitrogen loading doesn't reset to zero on reaching the surface. Those "slow" tissues (bone, cartilage) still have a load of nitrogen to release. Go back in the water and bottom time is reduced for subsequent dives.

All of this and more is part of the open water certification course. Ignoring it isn't just not paying some instructor to drone on - getting it wrong can be fatal.

Therapy · 19-08-2009, 19:36

Quote:

Originally Posted by RBEmerson

If you're asking "how long can I stay down", in one sense, the answer is "as long as you have air".
........ the limit is somewhere between 200 and 300 minutes.

I have a good working knowledge of Nitrogen buildup when diving and other risks.

Thanks for the number.

quartersplash · 19-08-2009, 19:39

10 years ago I built a hookah for my boat out of a duel diaphram compressor off of a dental chair from a place called surplus center in the midwest for $69. A friend gave me an old 2nd stage dive regulator which I took apart and cut the spring that regulates the pressure as I guess the regulater works at 125 psi with tanks. I readjusted it to work at 40 psi (not so hard). Then I put an adjustable pressure bleed on the air accumilator tank that I built out of Schedule 80 pvc pipe with ends ($10) from Harbor freight tools for $3. I then purchased an air/water separator and PVC air lines from Harbor frieght for $30 and around $18 for 50 feet. It worked fantastic on a 1000 watt inverter for the 4 years that I had the boat. I used it many times for a couple hours at a time. Total cost around $130!
I am now building one out of the same type duel diaphram compressor, but with a new Subaru 4 cycle weedeater engine with a centrifical clutch and weighs around 7 lbs for (around $200). And all of the rest of the stuff is the same. The whole unit weighs around 13 lbs and I can take it anywhere. Cost around $500.