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.
Thanks for any suggestions
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.
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 am replumbing my air lines tomorrow. I want no water vapor in my paint
> area so heres what I am doing.
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
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.
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
"Lew Hodgett" < email@example.com> wrote in message
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.
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.
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.
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.
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
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.
Now what? Are you going to break the pipe dope seal every time you want
to get water out?
If your not doing that much finishing work and cannot have moisture in
the finish then you are going to have to bit the bullet and get a drier
( refrig ) or maybe nitrogen, How much of a problem if you have to
re-finish an item is it? You don't want moisture and you don't want to
buy the equipt to remove it.....well houston.......we have a
Call a welding supply house and find out how much for a tank and see if
it will do the work for you. Don't know of any other cheap air supply to
try. Good luck.
No, I think I had enough common sense to install a valve complete with 1/4
tube running to a drain.
Last year I had water vapor problem but it mainly occurred when I was
sandblasting a large item.I would occasionally get water dripping out of a
tool too, but the compressor was set up in a basement and really had no run
to condense the water out. I have since bought a new house and have set up
the shop and I just wanted to help get a handle on any water problems that I
may have here.I keep in touch when the humidity rises the I'll go out and
sandblast something, see how my efforts have paid 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?
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
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