Replumb air lines question

"Shopdog" <[email protected]> wrote in message
news:UyLgg.4946$im3.391@trnddc01...
> I am replumbing my air lines tomorrow. I want no water vapor in my paint
> area so heres what I am doing.
>
> Running 25ft line across the ceiling in my shop to the adjacent wall, at
the
> wall I will have a 5ft drop for water relief, at the 2.5ft mark will be my
> inlet at the top will be my outlet going to various work stations, at the
> HVLP I will have a disposable dessicant attachment.
>

You can get as elaborate as you want but all you really need to do - winter
or summer, is install a simple water trap, drain cocks at the low points of
every drop, and then simply drain off any water in your tank and lines just
before you shoot. You don't have to drain the entire tank. You'll see when
it has purged the water. Do this every day you're going to shoot and you
have nothing further to mess with or maintain, and you won't get water in
your spray. I shoot an entire car without draining my tank more than one
time in the beginning so you certainly can shoot your workpiece. Oh yeah -
the most important part in my opinion - those little water trap bulbs that
screw into the air inlet of your gun. Don't leave home without one.

--

-Mike-
[email protected]

Shopdog wrote:

> I am replumbing my air lines tomorrow. I want no water vapor in my paint
> area so heres what I am doing.

<Snip>

I've posted this before, so this is a short hand version.

Buy a full 20 ft length of 2" black pipe, have it cut and threaded in 5
ft lengths.

Assemble using 2 run x 2 run x 3/4 side tees and 2x2x2 end fittings to
form a 20 ft run.

Hang assembly overhead with 1/12 pitch and 3/4 side fittings of tees
pointing up towards ceiling.

Install two (2), 3/4" street ells to form a "U" shape take off for air
hose connection. (This forces the air to first go up, then over, then
down and is a natural water trap)

Install a drain petcock in low point.

What I have described ism a very basic distribution that will eliminate
90% of your water problems.

Supporting engineering documentaion available, I'm just to damn tired to
post it tonight.


Good luck.


Lew

"Edwin Pawlowski" <[email protected]> wrote in message
news:ptXgg.4276$vq3.2285@trndny09...

>
> Sure they do. The humidity is the amount of water held by the air. The
> higher the humidity, the more water vapor in the air, the more
condensation.
> The longer the run, the greater the chance of the vapor condensing before
it
> gets to the point of use. Industrial dryers cools hte air using a
> refrigerant so the moisture condenses out at that point and is not carried
> in the system. If you have a 100' foor run it is more likely to condense
> the moiusture than a 5' run.
>
> Another factor in the moiusture at the point of use is the tank, and when
it
> is filled. If you start the compressor, bring the system up to pressure,
> then just leave it, the moisture will probably condense int he reciver and
> can be drained. If air flow is immediate and of large use, it is more
> likely to be carriesd out. Right now, our compressor air temperature is
275
> degrees. By the time it gets to the chiller, it is down to 100 degreess,
> then it h its a 40 degree thermal mass to condense out what is left. If
the
> flow was not continuous, it could condense in the receiving tank, but with
a
> use of 600 to 70o cfm, that does not happen.
>

I don't argue with the principles you explain Edwin, but with the real world
occurrances. I do a lot of spray painting and I'm not sure what your
experiences are, but mine are as I described. I live in Central NY which
enjoys a reasonably high humidity and as I stated in a previous post, I have
repeatedly painted an entire car with no moisture problems by following what
I had suggested to the OP. Perhaps your experiences differ? Certainly the
OP is not going to use as much air as I do when I paint a car, making him no
more susceptable to moisture issues than me.

>
> >
> > But - he will not encounter a problem with moisture in spraying if he
> > hangs
> > a water trap on the wall, uses a trap on his gun and drains the system
> > before each day of spraying.
>
> Perhaps. Every system, every use is different. Your method takes a large
> portion of the water out, but it may not work as well for a different
setup.
>
>

For the application in question it will work well. Moisture build up is
reasonably predictable and some simple precautions will indeed work.
Again - he's talking about a lot lighter usage than what I put my system
through, so he'll see less of a moisture problem. Of course - assuming a
reasonable compressor to start with, but even smaller ones will perform very
well for a long time. I used to shoot cars with a Sears 5HP/33gal unit.
With that compressor I used to drain the tank anytime I changed over what I
was shooting. Shoot primer - drain the tank. Shoot base coat - drain the
tank. Shoot clear - drain the tank. I never had a problem that lead me to
this ritual, but because the system was so small I took the precautions just
to be safe. It was probably a bit of overkill, but it didn't take too long,
and it didn't cost anything to do it.

--

-Mike-
[email protected]

"Shopdog" <[email protected]> wrote in message
news:UyLgg.4946$im3.391@trnddc01...
>I am replumbing my air lines tomorrow. I want no water vapor in my paint
>area so heres what I am doing.
>
> Running 25ft line across the ceiling in my shop to the adjacent wall, at
> the wall I will have a 5ft drop for water relief, at the 2.5ft mark will
> be my inlet at the top will be my outlet going to various work stations,
> at the HVLP I will have a disposable dessicant attachment.
>
> So, my question is, how will this fare to help rid my paint of water
> vapor. Right now I have no obvious water but summer humidity is not yet in
> full swing, so I am trying to stop a future problem.
> No, I cannot afford an air dryer, so that is out of the question. I am
> trying to minimize the cost so I can add to my tools.
>
> Spraying items will be few and far between.

You want water filter of some type as close to the sprayer as possible.
The water can condense anywhere in the air line including the hose connected
to the sprayer. The more the compressor runs during a spray session the
more condensation will be a problem from the heated compressed air.

"Mike Marlow" <[email protected]> wrote in message
> I don't argue with the principles you explain Edwin, but with the real
> world
> occurrances. I do a lot of spray painting and I'm not sure what your
> experiences are, but mine are as I described. I live in Central NY which
> enjoys a reasonably high humidity and as I stated in a previous post, I
> have
> repeatedly painted an entire car with no moisture problems by following
> what
> I had suggested to the OP. Perhaps your experiences differ? Certainly
> the
> OP is not going to use as much air as I do when I paint a car, making him
> no
> more susceptable to moisture issues than me.

I don't have much experience with spray painting, but I do run a 150 Hp and
a 75 HP compressor that feeds air operated controls on machines. The 150
runs 24/5. The 75 used to be the "big" compressor, but now is molstly
backup. The controls and machines (plenty of air operated pistons) don't
work as well when moisture is in the air. A machine can have as many as 50
air operated devices times 15 machines. We have a mechanical dryer that
can handle 1200 CFM. Thre are two receivers with automatic drains before
the machine. Take the dryer out of the system, you can shoot water from an
air gun. We also have an oil separator. Real world enough?

A few years ago I was having a lot of moisture problems with my compressed
air system. A friend suggested that I buy a special filter that uses a roll
of toilet paper as the filter media. I bought one at the local auto paint
supplier for about $30 and I connect it in the air line to the spray gun or
other air tool whenever I absolutely can't tolerate any moisture. A new roll
of paper (cheap stuff - you don't need Charmin) before each day's use
(remove it after use) and it has never failed to provide the dry air that
I've needed.

--
Charley

"Lew Hodgett" <[email protected]> wrote in message
news:[email protected]...
> Shopdog wrote:
>
> > I am replumbing my air lines tomorrow. I want no water vapor in my
paint
> > area so heres what I am doing.
>
> <Snip>
>
> I've posted this before, so this is a short hand version.
>
> Buy a full 20 ft length of 2" black pipe, have it cut and threaded in 5
> ft lengths.
>
> Assemble using 2 run x 2 run x 3/4 side tees and 2x2x2 end fittings to
> form a 20 ft run.
>
> Hang assembly overhead with 1/12 pitch and 3/4 side fittings of tees
> pointing up towards ceiling.
>
> Install two (2), 3/4" street ells to form a "U" shape take off for air
> hose connection. (This forces the air to first go up, then over, then
> down and is a natural water trap)
>
> Install a drain petcock in low point.
>
> What I have described ism a very basic distribution that will eliminate
> 90% of your water problems.
>
> Supporting engineering documentaion available, I'm just to damn tired to
> post it tonight.
>
>
> Good luck.
>
>
> Lew
>
>
>

"Edwin Pawlowski" <[email protected]> wrote in message
news:[email protected]...

>
> I don't have much experience with spray painting, but I do run a 150 Hp
and
> a 75 HP compressor that feeds air operated controls on machines. The 150
> runs 24/5. The 75 used to be the "big" compressor, but now is molstly
> backup. The controls and machines (plenty of air operated pistons) don't
> work as well when moisture is in the air. A machine can have as many as
50
> air operated devices times 15 machines. We have a mechanical dryer that
> can handle 1200 CFM. Thre are two receivers with automatic drains before
> the machine. Take the dryer out of the system, you can shoot water from
an
> air gun. We also have an oil separator. Real world enough?
>

Yeah baby! That's what I'm talkin' about! Now that's a man's toy. I
thought you must have been referring to usage and duty cycle similar to what
you just described when you first posted about my comments. Very real
world... just a tad different world than what we're working in.

BTW... have you considered one of those Harbor Freight sniffers for the
150HP compressor?....

--

-Mike-
[email protected]

"Edwin Pawlowski" <[email protected]> wrote in message
news:[email protected]...
>
> "Mike Marlow" <[email protected]> wrote in message
> >
> > You can get as elaborate as you want but all you really need to do -
> > winter
> > or summer, is install a simple water trap, drain cocks at the low points
> > of
> > every drop, and then simply drain off any water in your tank and lines
> > just
> > before you shoot. You don't have to drain the entire tank. You'll see
> > when
> > it has purged the water.
>
> It may work for your circumstances and can be a good starting point, but
it
> is not necessarily going to work for everyone. Compressor size, amount of
> air used, length of runs, ambient temperature and humidity all come into
> play.

You are correct - compressor size does have a lot to do with it. I
overlooked that in my response. The amount of air used is somewhat defined
though by the poster's question in that he intends to spray finishes.
Length of runs, temperature and humidity really don't have that much to do
with it - assuming enough compressor in the first place, if you drain the
water before a spray, and use a gun mounted water trap.

>
> The moisture in the line is a given. It is a product of compressing the
> air, increasing the temperature, and having the vapor condense. Adding
> traps does not change the laws of physics. If it was a mere matter of
> draining out drops, there would be no need to make a refrigerant dryer for
> ensuring dry air.

But - he will not encounter a problem with moisture in spraying if he hangs
a water trap on the wall, uses a trap on his gun and drains the system
before each day of spraying.

--

-Mike-
[email protected]

"Mike Marlow" <[email protected]> wrote in message
>
> You can get as elaborate as you want but all you really need to do -
> winter
> or summer, is install a simple water trap, drain cocks at the low points
> of
> every drop, and then simply drain off any water in your tank and lines
> just
> before you shoot. You don't have to drain the entire tank. You'll see
> when
> it has purged the water.

It may work for your circumstances and can be a good starting point, but it
is not necessarily going to work for everyone. Compressor size, amount of
air used, length of runs, ambient temperature and humidity all come into
play.

The moisture in the line is a given. It is a product of compressing the
air, increasing the temperature, and having the vapor condense. Adding
traps does not change the laws of physics. If it was a mere matter of
draining out drops, there would be no need to make a refrigerant dryer for
ensuring dry air.

"Edwin Pawlowski" <[email protected]> wrote in message
news:[email protected]...
>
> It may work for your circumstances and can be a good starting point, but
> it is not necessarily going to work for everyone. Compressor size, amount
> of air used, length of runs, ambient temperature and humidity all come
> into play.


Exactly. A good point to start. You have to remove all moisture to keep it
from coming out of the air lines. Moisture moves with the air and the
greater the difference in the hotter compressed air temperature than the
outside temperature the bigger the problem with immediate condensation as
it cools and when it exits the hose.

I listened to what everyone said and this is what I have done.

I ran 25ft across my ceiling added a water/particle trap. the intake is
2.5ft below the output, hoping that water will run down before going UP to
the outlets.
I sealed the pipe with pipe thread sealant instead of teflon tape.
Everything is leak free and I now have 4 air stations plus room for 2 more
if needed later.


Thanks again

Searcher

"Mike Marlow" <[email protected]> wrote in message

> Length of runs, temperature and humidity really don't have that much to do
> with it - assuming enough compressor in the first place, if you drain the
> water before a spray, and use a gun mounted water trap.

Sure they do. The humidity is the amount of water held by the air. The
higher the humidity, the more water vapor in the air, the more condensation.
The longer the run, the greater the chance of the vapor condensing before it
gets to the point of use. Industrial dryers cools hte air using a
refrigerant so the moisture condenses out at that point and is not carried
in the system. If you have a 100' foor run it is more likely to condense
the moiusture than a 5' run.

Another factor in the moiusture at the point of use is the tank, and when it
is filled. If you start the compressor, bring the system up to pressure,
then just leave it, the moisture will probably condense int he reciver and
can be drained. If air flow is immediate and of large use, it is more
likely to be carriesd out. Right now, our compressor air temperature is 275
degrees. By the time it gets to the chiller, it is down to 100 degreess,
then it h its a 40 degree thermal mass to condense out what is left. If the
flow was not continuous, it could condense in the receiving tank, but with a
use of 600 to 70o cfm, that does not happen.


>
> But - he will not encounter a problem with moisture in spraying if he
> hangs
> a water trap on the wall, uses a trap on his gun and drains the system
> before each day of spraying.

Perhaps. Every system, every use is different. Your method takes a large
portion of the water out, but it may not work as well for a different setup.