Compressor air water content

[DickyDoDah]

I'm considering doing some painting but I have no idea if my compressor and the DIY air cooler I have made is effective. I also have a PCL DropOut filter fitted just before my hose reel which seems to work well but I'm not sure. How can I test the water content of the air at the end of the hose? I will also be using this air for my plasma cutter which also needs dry air.

 

[winchman]

We do this at work but its a very expensive machine, I know some compressor or Air Dryer companies offer a testing service but I doubt its cheap.
I am sure Aliexpress will have something

 

[voipio]

As @winchman says, completely dry compressed air requires expensive hardware. Oil mist can also be an issue.

Try pointing a clean spray gun, without any paint in it, at a clean window or mirror, and do a dummy spray job, letting the gun run for a couple of compressor cycles. If there's a problem, it will become evident.

 

[DickyDoDah]

As @winchman says, completely dry compressed air requires expensive hardware. Oil mist can also be an issue.

Try pointing a clean spray gun, without any paint in it, at a clean window or mirror, and do a dummy spray job, letting the gun run for a couple of compressor cycles. If there's a problem, it will become evident.

A clean window in my workshop might be a challenge I'll try that. I do have an oil/water separator after the cooler and before the tank which does seem to collect a bit of both. I have fitted an auto drain as well that is on a timer to ensure no condensate sits in the bottom of the tank. Hopefully these should make it quite dry.

 

[carbon]

You can get a filter to add before the spraygun Filter

 

[DickyDoDah]

You can get a filter to add before the spraygun Filter

That looks interesting. I'm hoping my air is quite clean so will be ok for most things. That filter will be perfect if it needs just a little bit more.

 

[mightymig]

I think you would need a dew point sensor to measure it and they’re not cheap even from Chyna (don’t know accuracy of those ones either). People use them for air bearings I think and set alarms because the sensor is a lot cheaper than a new air bearing spindle

 

[mightymig]

A diy option would be to use a desiccant diy filter with a clear container so you can see the colour or how fast the colour of the desiccant changes

 

[the snooper]

It's recommended to have at least 18 feet of airline between compressor and water separator because the air heats them up and they stop working (condensing)

 

[brightspark]

and i wouldnt be using a coiled up hose reel airline there the worst thing possible for spraying and building up water in the coils then chucking it all though. there best been used strait

 

[brightspark]

i sometimes take the air from my twin compressor or the diesel screw comp for my airfed helmet .it goes through a decent water seperator then a filter and to the helmet .it has a nylon tube with holes in that goes around the front of the helmet spraying the air down over . ive wrapped it with white cotton sheet and check it every so often, its allways clean so i know im not breathing crappy air

 

[bricol]

Never seen any hint of water or oil after fitting my drop-out.

 

[julianf]

I find that, if I keep the water trap pressurized for long enough, without manually emptying it, my paint goes wrong, and (historically, although I'm wise to it now) I then spend an age trying to work out why, before realizing that the trap is full.

In this, I'd suggest it's quite obvious when things fail to work.

 

[brightspark]

i use a secondary tank on the end of the airline that catches 99 percent of the water then a short hose to my blast pot water seperator .it has a drain tap i put on under the bowl.all i do is leave it slightly open with a slight hiss of air and any collected water just blasts out it never gets in to the sand or the pot or a spray gun

 

[Erie Fred]

I think you would need a dew point sensor to measure it and they’re not cheap even from Chyna (don’t know accuracy of those ones either). People use them for air bearings I think and set alarms because the sensor is a lot cheaper than a new air bearing spindle

Like everyone else does ?

Just do as suggested with cooling, velocity reduction, deccasint & oil mist filtration, and you'll be just fine.

 

[premmington]

Dropout membrane fitlers is what I been using.

They work - they really do!

Not sure how many hours they will do thou

 

[DickyDoDah]

Thanks guys, I have a few things that I may change in my setup after all that advice. I reckon I'll be putting in another outlet so I can bypass the hose reel. I didn't think it would be best for spraying anyway as it's a bit heavy, I use it mostly for tools anyway. If I go ahead with spraying I'll probably use an inline filter just to be safe. Hopefully the PCL DropOut will be doing as hoped/expected and I'll already have good air.

 

[Erie Fred]

MotorGuard is popular....filter element is a .....a ......roll of toilet paper.

 

[henry Kadzielski]

MotorGuard is popular....filter element is a .....a ......roll of toilet paper.

As has @Erie Fred has suggested, down the line. They stop water as well as oil mist. And everyone has spare filter elements. They can also be easily inspected for contamination

 

[mightymig]

Like everyone else does ?

Just do as suggested with cooling, velocity reduction, deccasint & oil mist filtration, and you'll be just fine.

Was answering the original question. What do you mean like everyone else does?