Air compressor for hull cleaning
 

MMC writes:

Could it be that the rings in your compressor aren't shot? Breathe the
exhaust of any of the other items you list at depth and under pressure
and let me know what you find out.

You're in full definitional retreat. We're talking about using a sound
compressor to dive just below the surface to work on a boat hull. Not a
busted compressor and plumbing the abyss.

Air compressor for hull cleaning
 

This thread is getting dumber and dumber.
Neither nitrogen narcosis nor embolism
have _anything_ to do with breathing oil fumes
or other garbage.

Everybody go back and study physics 101 and biology 101.
If that seems confusing, borrow highschool textbooks
from your teenage children. Do not post before finished.

Good night.

Air compressor for hull cleaning
 

Dave writes:

so one cannot by breathing oil-contaminated air at one atmosphere draw
any conclusions about the effect of breathing oil-contaminated air at
multiple atmospheres.

The irrelevance was the reference to "multiple atmospheres" and the
vacant definition of "oil contaminated".

It's great that the macho diver men know all about deep diving and air
purity. It doesn't earn you bragging rights for improvised hookah.

We po' boat do-it-yourself'ers are jus' tryin' to dunk under the surface
to work on the hull. The shop air and 1970s ScubaPro 2nd stage works
fine. Looks good, tastes good, smells good, breathes good. No residues
in the hoses or gear, no irritation felt, no respiratory effects noted
whatsoever. No measurable loss of oil in the crankcase after hours and
hours of runtime. Forgive my moral courage in scientifically evaluating
a system for PEL and risking my lungs on a measured negative conclusion.
The likelihood of being harmed by an error in judgment in this
enterprise is negligible compared to errors in driving down the road
this week.

Invisible-things-will-get-you is a habit of the uncritical or unbalanced
mind. I've looked in the closet, and there is no monster there. No
radon in the basement, no toxic mold in the walls, no dust mites in the
ducts, no subluxations in the spine, no bad humours in the shop air.

Air compressor for hull cleaning
 

Actually, for anyone with a modest ability to read between the lines, MMC's
reference to those two risks are highly relevant. His point is that

Physic 101 doesn't require much reading between the lines. But
it does require the reading.

o just as one cannot, from breathing air at 1 atmosphere of pressure,
draw any conclusions about the narcotic effects of nitrogen partial pressure
at multiple atmospheres, and

Nobody tried that, that's why the N2 is so off the point.
And, of course one can, there even is a formula:
Each seven meters equal one martini, or so I hear the man in the red
hat said. But what is the effect of so many olives at depth? After all,
olives are where the oil comes from, are they? Does it become worse If
the olives are vaporized? So, should one chew them or swallow them
hole?

o just as one cannot, from holding one's breath at one atmosphere draw
any conclusions about the effect on the lungs of holding one's breath while
ascending from, say 30 feet after breathing compressed air,

Of course one can, physics 101 again. Pressure change, volume change,
ouch.
You aren't confusing lung rupture with embolism, are you? Or how did
that tidbit of diving physics pop up here?

so one cannot by breathing oil-contaminated air at one atmosphere draw any
conclusions about the effect of breathing oil-contaminated air at multiple
atmospheres.

Yadda. No one was trying to go deep with the compressor, be it oily or
not. Remember, we are talking keel deep here.

Understanding the point does, however, require a moment's thought--something
often in short supply.
Oh, so true.

Air compressor for hull cleaning
 

Richard J Kinch wrote:

Dave writes:

so one cannot by breathing oil-contaminated air at one atmosphere draw
any conclusions about the effect of breathing oil-contaminated air at
multiple atmospheres.

The irrelevance was the reference to "multiple atmospheres" and the
vacant definition of "oil contaminated".

It's great that the macho diver men know all about deep diving and air
purity. It doesn't earn you bragging rights for improvised hookah.

We po' boat do-it-yourself'ers are jus' tryin' to dunk under the surface
to work on the hull. The shop air and 1970s ScubaPro 2nd stage works
fine. Looks good, tastes good, smells good, breathes good. No residues
in the hoses or gear, no irritation felt, no respiratory effects noted
whatsoever. No measurable loss of oil in the crankcase after hours and
hours of runtime. Forgive my moral courage in scientifically evaluating
a system for PEL and risking my lungs on a measured negative conclusion.
The likelihood of being harmed by an error in judgment in this
enterprise is negligible compared to errors in driving down the road
this week.

Invisible-things-will-get-you is a habit of the uncritical or unbalanced
mind. I've looked in the closet, and there is no monster there. No
radon in the basement, no toxic mold in the walls, no dust mites in the
ducts, no subluxations in the spine, no bad humours in the shop air.

Well, go ahead on and try it then.

If you can still type afterwards, let us know, ok?

Thank you.

Air compressor for hull cleaning
 

Well Dave, in Navy diving ops there is a "standby diver" who in hardhat
diving is completely dressed with exception of the helmet, which takes all
of, let's say 5 seconds to don.
The stay time may have been longer if the suit were fully inflated. Anyone
that has dove the Mk 5 can tell you that if the suit (or any dry suit with
an air fill) is fully inflated, the diver will be wriggling around on the
surface bobbing like a cork.
The o2 starts at 21% and when it drops to 16% the diver starts to experience
hypercapnia AND hypoxia.
The rig was designed to sustain life underwater. Attaching the hose with a
nut was the highest tech option they had at the time.
MMC
"Dave" wrote in message
...
On Wed, 26 Apr 2006 13:41:50 GMT, "MMC" said:

As I remember a Mk 5 diver would be conscious for something like 6
minutes
if he lost his air supply

My recollection is that it would be significantly more than that.
Remember,
we're talking about the time required to reduce the percentage of oxygen
in
the fixed amount of air contained in the suit and hat combined to below a
level that will sustain life. The rig was designed so the if the air hose
where cut completely you could send another diver down with a new hose and
hook it up to the hat. I'd be surprised if that could be done in under 6
minutes except in the most exceptional circumstances.

Air compressor for hull cleaning
 

Dave,
Please excuse my condescending previous reply to this post. I didn't know
your background.
MMC

"Dave" wrote in message
...
On Wed, 26 Apr 2006 13:41:50 GMT, "MMC" said:

As I remember a Mk 5 diver would be conscious for something like 6
minutes
if he lost his air supply

My recollection is that it would be significantly more than that.
Remember,
we're talking about the time required to reduce the percentage of oxygen
in
the fixed amount of air contained in the suit and hat combined to below a
level that will sustain life. The rig was designed so the if the air hose
where cut completely you could send another diver down with a new hose and
hook it up to the hat. I'd be surprised if that could be done in under 6
minutes except in the most exceptional circumstances.

Air compressor for hull cleaning
 

Dave wrote:
On Thu, 27 Apr 2006 15:12:09 GMT, "MMC" said:

Well Dave, in Navy diving ops there is a "standby diver" who in hardhat
diving is completely dressed with exception of the helmet, which takes all
of, let's say 5 seconds to don.

Please don't try to explain to me how the Navy conduct diving ops. I
spent 3
years as a diver and diving officer on a ship where that was a primary
mission. Unfortunately your incomplete knowledge is showing. How does
this
second diver get down to the first diver? Do you think he simply gets
up an
jumps in after the helmet is secured? I don't think so.

Hi MMC:
Had to chime in with the non-union, pot smoking, rat divers approcah.
Uhh jump righ in........... yep. The tender better have a bunch of hose
in the water first.


The stay time may have been longer if the suit were fully inflated. Anyone
that has dove the Mk 5 can tell you that if the suit (or any dry suit with
an air fill) is fully inflated, the diver will be wriggling around on the
surface bobbing like a cork.

I have dived in that suit. While the suit would virtually never be
fully
inflated absent unusual circumstances, it is nearly always partially
inflated. The point is that there's far more air in the suit than just
what's in the helmet.

MMC, I concure. I would like to add, "....if the suit were fully
inflated..." as Dave says I think you Navy guys working the Standard
Navy deep Sea Dress Mod. 1 Mark V would call it an "uncontrolled
assent."


The o2 starts at 21% and when it drops to 16% the diver starts to experience
hypercapnia AND hypoxia.

Wrong except when you're at the surface. It's the partial pressure of the O2
that counts, not the percentage, and that partial pressure increases with
depth. In fact at sufficient depth a 16% heo2 mix could allow one to survive
breathing the mixture virtually indefinitely without such effects.

MMC, Agreed, again....... in the gulf we were using the same % bottom
mix for just about eveything under 420' if I remeber right. But could
be wrong. When I was a green tender I asked why use a standard botom
mix for such a large depth range. He said for simplicity. Did not want
a shop full of diffrent bottom mixes.

When you were doing gas jumps in the Navy did you calculate PPO2 and
mix specific bottom gas for each job? Or just use the "good enough"
approach?

Not all that Salty, Bob

Air compressor for hull cleaning
 

Richard Lamb writes:

Well, go ahead on and try it then.

Been doing it for years.

If you can still type afterwards, let us know, ok?

OK.

http://www.typingtest.com/test/default.asp

87 WPM, 97 percent accuracy.

Air compressor for hull cleaning
 

Now, I retrack my retraction. I had mistakenly come under the impression
that you were someone that worked for a living.
"MMC" wrote in message
...
Dave,
Please excuse my condescending previous reply to this post. I didn't know
your background.
MMC

"Dave" wrote in message
...
On Wed, 26 Apr 2006 13:41:50 GMT, "MMC" said:

As I remember a Mk 5 diver would be conscious for something like 6
minutes
if he lost his air supply

My recollection is that it would be significantly more than that.
Remember,
we're talking about the time required to reduce the percentage of oxygen
in
the fixed amount of air contained in the suit and hat combined to below
a
level that will sustain life. The rig was designed so the if the air
hose
where cut completely you could send another diver down with a new hose
and
hook it up to the hat. I'd be surprised if that could be done in under 6
minutes except in the most exceptional circumstances.