Am wondering if anyone has set up a small air compressor rig, 110V,
similar to the ones used by divers for hull cleaning services. I assume
just a small oil-less compressor and couple it directly to a stock dive
regulator? I only need it dockside in a marina with 30A seervice.

THANKS for any input

BajaJim wrote:
Am wondering if anyone has set up a small air compressor rig, 110V,
similar to the ones used by divers for hull cleaning services. I assume
just a small oil-less compressor and couple it directly to a stock dive
regulator? I only need it dockside in a marina with 30A seervice.

THANKS for any input


So you are saying that you want to set up a surface supplied diver air
system?
In other words ya want to breath the stufff pumped out of the
compressor?

Common Air Breather Bob

I've been using a system like this for 14 years - an invaluable tool.
Here are the details:
http://www.yandina.com/hints.htm#Compressor

Actually I stole the idea from Andina who used to be my "dockmate" at CBYC
about 100 years ago.
How are you and Lea? Sure was good seeing you last month.
MMC

"Andina Marie" wrote in message
oups.com...
I've been using a system like this for 14 years - an invaluable tool.
Here are the details:
http://www.yandina.com/hints.htm#Compressor

BajaJim:

Let's try to ignore all of the irrelavent BS that was recently posted to
this topic. An oil less air compressor is perfectly safe to use with a
simple filter to trap any particles that get through.

But your stock dive regulator won't work. It is designed to work with about
200 psi air supply. A typical Home Depot oil less compressor won't supply
enough pressure.

You need a "hookah" regulator that will work with about 25-50 psi supply
air. I bought mine from an outfit that sells equipment for small scale gold
mining. Google around and you should find one.

David

Am wondering if anyone has set up a small air compressor rig, 110V,
similar to the ones used by divers for hull cleaning services. I assume
just a small oil-less compressor and couple it directly to a stock dive
regulator? I only need it dockside in a marina with 30A seervice.

The diver that cleans my boat does it that way and I know of one other in
this area.


Leanne

The compressor might work, but I would use a dive tank.
Cheaper, easier, claener air, more reliable.
You can get a new one for under $100, a used one for half of that.
One air fill will last you hours when you stay as shalllow as the hull
of a boat. If you like the setup with th long hose, use it and leave
the tank on board.
You are going to buy 90% of a full set of scuba gear anyway, why stop
at the tank?

BajaJim writes:

Am wondering if anyone has set up a small air compressor rig, 110V,
similar to the ones used by divers for hull cleaning services. I assume
just a small oil-less compressor and couple it directly to a stock dive
regulator?

Yes, we do this in our swimming pool. I run an old ScubaPro regulator 2nd
stage ($25 on eBay) off 90 psig shop air from a standard piston/oil type
compressor. Despite all the dire warnings (from people just reciting
paranoia they've heard, who've never tested for oil or tried it), the air
should be OK if your compressor doesn't consume oil such as from bad piston
rings. And the pressure is fine for feeding a 2nd stage.

The fear of "any oil in air will harm you" is silly. First, it is mineral
oil, which is non-toxic. Second, if were that bad, a whiff of 2-cycle
exhaust would kill you. I run this compressor for hours and hours,
thousands of cubic feet, and it loses only tiny amounts of oil, most of
which condenses in the tank.

I suppose an oilless compressor would eliminate even the possibility of
entrained oil. Although they're hideously noisy. You would want at least
a 2 cfm compressor rating, since you typically breathe about 1 cfm. But 2
cfm at 90 psi is only about a 1/2 (true) horsepower unit.
But see my essay http://www.truetex.com/aircompressors.htm on horsepower
ratings.

You need an adapter from the SAE scuba fitting to NPT pipe thread and
thence to a shop air quick-connect, which all then goes on your regulator
second stage hose where it would have connected to a first stage. You now
have a scuba regulator that terminates in an air tool quick-connect. I
made my own threaded adapter on my machine shop lathe. The only source for
such a part otherwise that I can think of is the adapters made for buoyancy
compensator connectors to shop air for filling tires or running tools from
scuba tanks (although this is the opposite direction of adaptation, it
might have the critical SAE-fitting-thread to NPT-pipe-thread conversion).
You could do it by simply splicing hoses with a hose barb if you were
willing to cut up the regulator feed hose.

Here is my drawing of the adapter essentials:

http://www.truetex.com/scuba_lp.pdf

Shallow water hookah diving is easier than most open water scuba diving.
The dive gear industry makes everything but this year's model sound like
it's going to kill you. The old 2nd stage regulators were very simple and
easy to repair yourself. They too were once the thing you had to have and
all the old models would kill you.

If anyone wonders if this is unreliable and therefore hazardous, I would
only use it for shallow diving, like working or practicing diving in a
swimming pool, or working on a boat hull, and I would insist on having a
trustworthy person for a topside tender. Being suddenly out of air is not
a problem with some simple training; we as tenders routinely disconnect the
air unexpectedly to our diving family members to help them practice the
drill (a habit I got from my first scuba instructor in the 1970s, who liked
to turn off your main valve when you weren't expecting it).

To anyone suggesting you just go full scuba instead of improvising a
topside compressor, I would say that full scuba is absurdly cumbersome and
expensive compared to hookah for shallow diving on a fixed location, and in
my opinion, no improvement in risk.

Of course this is diving, which takes training and recent diving experience
to minimize risks.

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.

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