Good post Robb.
The toxins are minute until the compressor pistons rings get worn (or do not
fit right from the beginning) and allow oil to enter the cylinders. With the
heat that's generated by compressing air, the oil will partially burn and
create carbon monoxide which coats the red blood cells and prohibits the
transfer of oxygen to those cells and further to the other cells in the
body.
Absolutely right about the oil free compressor!
MMC
"AMPowers" wrote in message
...
BajaJim wrote:
MANY Thanks to Richard Kinch and Bryan Combs for some great replies, it
was clear that they understood I am only going down 6 to 8 feet and
just need a little compressor, similar to those used for small paint
sprayers. I will also have 30A dock service to plug into.

This was my first post and participation and, while I love a little
humor as much as the next guy (see my book The Baja Bash), it was a
little hard finding the worthwhile posts while sifting through others
from people who clearly feel a need to reply to anything and
everything, under the assumption that they know all and should
therefore pass on their pearls of wisdom.


Jim,

I believe that the warnings you received about "oil" based compressors
are based on the concern that you might be exposing yourself to what are
admittedly small amounts of toxins but over long periods of time, all
while working underwater - an environment where one would like to avoid
encountering breathing issues.

To compound this further you will be most likely be exerting yourself
enough to raise your respiration rate which would increase any toxin
absorption rate. Also, because of the "partial pressures" of breathing
gases in increased atmospheres, the percentage of toxin absorbed by your
body goes up dramatically as you go deeper.

If you can avoid using an oil based compressor I would strongly suggest
doing so, especially since inexpensive alternatives exist.

Cheers,

Robb

MMC wrote:
Good post Robb.
The toxins are minute until the compressor pistons rings get worn (or do not
fit right from the beginning) and allow oil to enter the cylinders.
Absolutely right about the oil free compressor!

Thanks for adding your ideas here. Finally some advice based on
training, experince, and still here to give it. Unlike the other past
posts that simply said, "Ive been doing it this way for years and never
had any porblems."

Here is my question for you MMC:

A few comments earlier in this discssion I described a hand pump that
supplied diver air to about 20'. Did you ever run into anything like
that in the service? They were a little (maybe 25 lbs.) two cylinder
thing with a five foot handle that a person push-pulled too operated
the pump. The guy who made the new prototype said he got the idea from
one he saw in an old USN Dive Manual.

Thanks,
Bob

MMC writes:

The toxins are minute until the compressor pistons rings get worn (or
do not fit right from the beginning) and allow oil to enter the
cylinders. With the heat that's generated by compressing air, the oil
will partially burn and create carbon monoxide which coats the red
blood cells and prohibits the transfer of oxygen to those cells and
further to the other cells in the body.

You are confusing heat and temperature, because compressing air does not
generate heat. The existing heat is concentrated into a smaller volume,
raising the temperature, but this does not rise to ignition at 90 psi.
Perhaps you are thinking of scuba tank compressors at many 1000s of psi.

If what you say were true, then working with compressed air in a closed
shop would be even more hazardous, since the air is recycled over and
over through the compressor as it is exhausted into the room. But there
is no CO or oil vapor to be concerned with in those situations.

Mineral oil is not toxic in itself.

You are breathing oil-contaminated air all the time, over a cooking
stove or around 2-cycle engines. No one thinks much of it, because it
isn't a hazard.

:
MMC writes:

The toxins are minute until the compressor pistons rings get worn (or
do not fit right from the beginning) and allow oil to enter the
cylinders. With the heat that's generated by compressing air, the oil
will partially burn and create carbon monoxide which coats the red
blood cells and prohibits the transfer of oxygen to those cells and
further to the other cells in the body.


Richard J Kinch wrote
You are confusing heat and temperature, because compressing air does not
generate heat.

Way big mistake..........! Please consult Charles Law

The existing heat is concentrated into a smaller volume,
raising the temperature, but this does not rise to ignition at 90 psi.
Perhaps you are thinking of scuba tank compressors at many 1000s of psi.
If what you say were true, then working with compressed air in a closed
shop would be even more hazardous, since the air is recycled over and
over through the compressor as it is exhausted into the room. But there
is no CO or oil vapor to be concerned with in those situations.

Mineral oil is not toxic in itself.

Now that depend on where you are breathing a contaminated gas mix that
includes Mineral Oil present. The term that MMC used is worth
researching: Partial Preasure.

You are breathing oil-contaminated air all the time, over a cooking
stove or around 2-cycle engines. No one thinks much of it,

Uhh. I do!

because it isn't a hazard.

Did I just bit on a troll?
This has got to be a troll.

If not........... for anyone wanting to breath compressed air please do
not belive anything posted here.
Bob

Bob writes:

You are confusing heat and temperature, because compressing air does not
generate heat.

Way big mistake..........! Please consult Charles Law

Charles's Law relates pressure and temperature. Not heat. Learn the
difference.

Richard J Kinch wrote:

Charles's Law relates pressure and temperature. Not heat. Learn the
difference.

Dear Richard:

Please explain the relationship between pressure and heat and
temperature. I think temperature and heat might be similar. But how?
That is BTU = Degrees Fahrenheit. So what is missing?
We can get into a discussion about pressure-heat - volume when the sun
is up.

Ignorant Bob.

How often are you planning on using this? I just use a scuba tank
with a 40' hose to do all my maintenance.... no worries about maint or
worn rings or electricity.

If you use it a lot, contact brownies third lung. They make a safe
electic unit as well. Sure it costs a few more bucks but we are
boaters... If you can't right the checks, stay on the dock!!!!!





Bob wrote:
Rick Morel wrote:

On 20 Apr 2006 12:29:35 -0700, "BajaJim" wrote:


------------------------------------------------
Absolute safety is a concept promoted by those
without the guts to live in the real world.
------------------------------------------------



I think Absolute safety is a great goal. Most times not relaistic
but.......
Personnaly, I follow this:

"Its the second mouse that gets the cheese."

Observe.............anticipate.................... improve and
innovate.
Relationships with friends and coworkers tend to be longer this way

Bob

Richard J Kinch wrote:
MMC writes:


The toxins are minute until the compressor pistons rings get worn (or
do not fit right from the beginning) and allow oil to enter the
cylinders. With the heat that's generated by compressing air, the oil
will partially burn and create carbon monoxide which coats the red
blood cells and prohibits the transfer of oxygen to those cells and
further to the other cells in the body.


You are confusing heat and temperature, because compressing air does not
generate heat.

Nonsense. The "compression of air", i.e. the volume change alone, does
not change heat content(enthalpy), however mechanically "compressing
air" always does. Any mechanism that compresses air does work on the
system (consider all the frictional components), and that work is
reflected in increased temperature and enthalpy.

The existing heat is concentrated into a smaller volume,
raising the temperature, but this does not rise to ignition at 90 psi.

Ignition temperatures are not required, however, to generate volatilized
oxidation components. CO is not likely to be an issue without
ignition-high temps, but I'd just as soon not breath contaminated oil vapor.

Perhaps you are thinking of scuba tank compressors at many 1000s of psi.

If what you say were true, then working with compressed air in a closed
shop would be even more hazardous, since the air is recycled over and
over through the compressor as it is exhausted into the room. But there
is no CO or oil vapor to be concerned with in those situations.

Hardly the same context given the dilutional differences. A "closed"
shop is *not* a sealed shop.

Mineral oil is not toxic in itself.

In the gut, no. In the lungs, yes. Coat your alveoli with it and see
how long you last. The lungs have mechanisms for clearing particulates,
but not oils. And let's not forget that the oil has lots of other
charming things in it (like heavy metals from wear surfaces) by the time
it gets to your lungs.

You are breathing oil-contaminated air all the time, over a cooking
stove or around 2-cycle engines. No one thinks much of it, because it
isn't a hazard.

Well, I'd suggest that most people think more about it than you do. And
in most of those situations, you're getting particulates, not
volatilized oil. You're also breathing through your nose, which is
designed as a filter (i.e. impingement on mucosal linings of the nasal
and sinus passages), which you will not be doing underwater, unless
using a full face mask.

Using an oil sealed compressor to supply breathing air is just stupid,
unless you care nothing for your health.

Keith Hughes

Keith Hughes writes:

You are confusing heat and temperature, because compressing air does
not generate heat.

Nonsense. The "compression of air", i.e. the volume change alone,
does not change heat content(enthalpy), however mechanically
"compressing air" always does.

I correctly responded to a misstatement of your "does not". Your
"always" is irrelevant.

I'd just as soon not breath contaminated oil vapor.

Then you better not cook over a stove or grill.

Hardly the same context given the dilutional differences.

So you must agree. Some oil is OK. How much? And what shred of
evidence do you have that a shop compressor exceeds that?

Mineral oil is not toxic in itself.

In the gut, no. In the lungs, yes.

Aspiration hazards are not toxicity hazards. By your logic, water is
toxic since too much of it in your lungs will kill you.

You are breathing oil-contaminated air all the time, over a cooking
stove or around 2-cycle engines. No one thinks much of it, because
it isn't a hazard.

And in most of those situations, you're getting particulates, not
volatilized oil.

So you must think a particulate oil fog is OK when a vapor isn't? That
cooking or running a 2-cycle or fogging for bugs isn't generating a lot
of oil vapor? Come on.

Using an oil sealed compressor to supply breathing air is just stupid,
unless you care nothing for your health.

Calling something a hazard when you have absolutely no data on the
levels, and where the oil consumption suggests negligible levels, and no
standards for permissible exposure, is what is ... I don't want to say
"stupid", but let's call it California style environmentalism.

OSHA PEL for mineral oil mist is 5 mg per cubic meter. Show that this
is exceeded in shop air at the delivery point. Don't just timidly
speculate.

Dave wrote:
On 23 Apr 2006 03:24:48 -0700, "Bob" said:


I think temperature and heat might be similar. But how?
That is BTU = Degrees Fahrenheit.

Sorry, Bob. You're dead wrong on this one.


Hi Dave:
Okay........... I agree, most likely wrong. Im not sure about the dead
part, although I felt like sunday morning. Thats what I was wondering.
Let try this: How is BTU related to Degrees Fahrenheit?

If air is compressed doesn't it get hot? If so, how measure it? But I
guess what caught my eye was when a previous post said that compressing
air does not create heat. But I may be pretty ignorant about the term
HEAT.

Confused Bob