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Water Problem with Air Compressor

43K views 45 replies 10 participants last post by  71gtx 
#1 ·
Hello guys, I am pretty new to painting cars. I am working on a project spraying with a gravity feed gun. I have a craftsman vertical 33gallon air compressor. I purchased a craftsman water trap/filter and mounted it stratight off of the compressor before attempting spraying. I used a hose that has the hard plastic outer shell. Well, I got water bubbles heavily in the area I tested.

I then took a DA and ran it and noticed that water was coming out heavily, but no water is collecting in the water trap. i was told i need a rubber flex hose rather than the one i have, but why isn't water trapping in the first place? any tips on how to set this up to eliminate all water?

I was also told to mount the water trap higher than the compressor to help?
 
#2 ·
The reason its not catching the water is cuz when it passes through the filter right at the compressor, it hasnt FORMED water yet. The airs still hot and doesnt form condensation til it starts cooling off, further down the line. As a rule of thumb, the further from a compressor you put a filter, the better it will be utilized.
 
#3 ·
air compressor water

hi,i have a 60 gal vertical compressor.heres what i did to solve the water problem. at the fitting where the air hose would connect,i took 1/2 in galvanized pipe (hardware store,hd or lowes) and made a long U shape 1 piece of pipe 2ft long,,vertical,90 degree fitting, water hose bibb,6in long horizonontal(bottom of U shape,) vertical piece of pipe 20 in long air hose fitting on end. in use i start compressor,let it fill up,open water bibb till water drains out close bibb,and spray. every 10 minutes or so,i drain water again. i also use a toilet paper water filter in air line just before regulator.(close to gun)
 
#4 ·
What you have is a classic example of why it is nearly useless to mount a water separator on the compressor itself. To understand it a little better, the water in the hot air coming from the tank is still in vapor form so it will pass right through the separator unit and then as the air cools the water will then condense on the air line walls and then, well you know what happens then. To paint you NEED a complete system and the compressor and air hose are only part of this system you also need to cool the air BEFORE it reaches the separator and there are several ways of doing this with the most common being a fairly long properly run pipe from the compressor to the separator and then to the air hose, This pipe is very important to the system and should not be left out. The pipe must be routed in such a way that the water that collects on the walls will drain down into collection 'drops" where it will remain undisturbed by the air flow until it is drained. This may sound complicated and hard to do but it really is quite simple and has been covered here a bunch of times in detail so do a search first on "air lines" and maybe one on "compressor" and you will find in recent posts some info on how to do this. There are several good ways so check them out and decide which way is best for you or there are a couple of other tricks such as air coolers between the tank and separator. Do that search then get back to this thread with any questions you may have and you will find help from a bunch of guys who have already done this and have systems that work really good, if you do that search then yours will too shortly. :)
 
#5 ·
oldred said:
The pipe must be routed in such a way that the water that collects on the walls will drain down into collection 'drops" where it will remain undisturbed by the air flow until it is drained. This may sound complicated and hard to do but it really is quite simple and has been covered here a bunch of times in detail so do a search first on "air lines" and maybe one on "compressor" and you will find in recent posts some info on how to do this.

Your air line should slant slightly toward a 'drop' which would be, at least in my opinion, a tee (T) with the airflow going along the top part and a length of the hard line going down with a plug for easy drainage (this is essentially an improved version of an aforementioned setup). And if you have an air distribution setup with the lines going around the walls, have a real quality air dryer at the 'outlet'. Using a clean air hose is a good idea, sitting on the floor unplugged they probably get alot of junk inside of them, perhaps also some air tool oil? (put oil into air tool, plug into line, and some oil seeps back into hose and forms dirt holding residue is my theory)

The little disposable filters right by the gun isn't a bad idea either.
 
#6 ·
Ok it seems to be hitting me now. I am going to run a hard line from the tank about 15' or so? What type of line is this called, and will any bends or angles up or down help this? Then attach the filter to the end of this hard line, run 50' hose off of that with a disposable filter attatched to the gun. Is this correct?
 
#7 ·
71gtx said:
Ok it seems to be hitting me now. I am going to run a hard line from the tank about 15' or so? What type of line is this called, and will any bends or angles up or down help this? Then attach the filter to the end of this hard line, run 50' hose off of that with a disposable filter attatched to the gun. Is this correct?
You can never have too many filters but place them at the end of the pipe run before the plug in for the hose...

This is a picture of my temp setup - I'll still add an air-line dryer down the road when I build an outside shed for the compressor...

This is about 100 bucks worth of copper pipe and fittings with a 50' reel hose (Lowes not sure on price its about 4 years old), the filter/regulator is from HF about 30.00

My shop is 22x40 so the retractable hose reaches all corners easily.

Copper works better for condensing the water than galvanized pipe. IMHO

 
#8 ·
No, Actually the hose length is not important it is the pipe that should be about fifty feet. I realize this is not always practical and the are ways around it. Your goal should be to condense as much water in the pipe between the compressor and the separator as possible and have this water drain down into collection "drops" where it can remain until it is drained. This is not nearly as hard to do as it sounds and there have been literally pages written here on how to do this, basically you will use the pipe as a heat exchanger that will cool the air thus allowing for condensation of the water vapor BEFORE it reaches the separator.

For a small shop with limited space the set up Rambo has is just about ideal, heck that would work good in a big shop :)
 
#10 ·
71gtx said:
am i seeking 1/2" copper pipe? Rambo, how many feet of it do you hvae there?
Approx 26' total

I bought 32ft of 1/2 Schedule L (M will work but L is thicker)

Each down is approx 4' and there is 2 pet-**** drains plus the drain at the filter/regulator and the compressor.

I barely get any moisture at the filter - so far no matter how long it cycles (depends on the tool I'm using). There might be some issues when it gets hotter outside - but I'm going to add a refrigerated line dryer to the copper system later this summer.
 
#11 ·
Definitely use a flex line from the compressor to the hard pipe, a hydraulic hose is perfect. It will be rated far in excess of any pressure it will ever see on a compressor, it will last just about forever, it is available in any size or length and is easily found with pipe fittings. Also the lowest rated hose will be around 1500 to 2000 PSI or so and will be inexpensive so you will not need a more costly high pressure hose.
 
#13 ·
Ok guys, I purchased the goods and am about to set it up. Heres what I'm doing:

I couldn't find threaded copper pipe so I went with galvanized. I have 10 3' galvanized pipes, going to go up and down 5 times like in Rambo's picture. At the bottom of each I will have a 5" T going down to a ball valve drain. So there will be 4 drain valves and finally the craftsman filter at the end.
 
#14 ·
71gtx said:
Ok guys, I purchased the goods and am about to set it up. Heres what I'm doing:

I couldn't find threaded copper pipe so I went with galvanized. I have 10 3' galvanized pipes, going to go up and down 5 times like in Rambo's picture. At the bottom of each I will have a 5" T going down to a ball valve drain. So there will be 4 drain valves and finally the craftsman filter at the end.
Galvanized pipe does not cool as well as copper - but should still give you enough to condensate the water on your down runs

btw you have to sweat/solder copper pipe together I've never seen any pipe that had threads.

Make sure you use a ball valve from the compressor to the flex hose that hooks into this system. If you ever get a blowout you want to be able to cap it off!
 
#15 ·
I agree that Copper would have been a better choice however it is not so much so that you need to change plans, the galvanized should work just fine. Be sure and seal the threads really good and use GOOD quality fittings preferably made in USA because some of that import stuff is just plain junk. :mad:
 
#16 ·
i attempted to use galvanized pipe but had quite a bit of leaks, even with using pipe sealant. the problem being that i would tighten each fitting but they had to be positioned a certain way so there was a certain amount it could be tightened and anymore and it would be out of place.

so, any suggestions and if not, what does it take to sweat the copper? i have experience with welding and soldering, just never have done copper. other option would be to weld all galvanized fittings in place.
 
#17 ·
I'm no pro at sweating copper but cleaning both mating surfaces is paramount - they make nice tools that do this...

Clean it swab it with flux and solder the joint by pointing the flame in the direction you want the solder to go. When it is done perfectly the joint will acutally pull the solder into the seam. If you practice with just a few extra pieces you'll get the hang of it.

I would wonder if welding the galvanized would compromse the metal? Welding is a lot more heat than solder...
 
#18 ·
Now you know why plumbers are paid so much! :D I would not attempt to weld the pipe, especially the galvanized. Sweating Copper pipe is easy and like Rambo said cleaning is the key to it because any oxidation left on the joint surface will most likely result in a leak, this however is no big deal and is only a matter of paying attention since cleaning it is easy. You can probably get the brushes where you get the pipe or at most any hardware store.
 
#19 ·
Make sure your connections are doped with pipe dope & tighten them up with at least 18" pipe wrenches, I used 24" on mine & haven't had any problems. If you used pliers or something other than pipe wrenches to tighten it up the problem may be that they aren't tight enough.
 
#20 ·
Another problem may be the fittings that's why I said earlier to use a good quality fitting (such as Ward) which is not always easy to find. The pipe and fittings should be bought from a plumbing supply and not the local McHome store because of the cheap import fittings that all too often have very rough poorly cut threads that are hard to seal, same goes for the pipe make sure the threads are cut clean.
 
#22 ·
well, i finally got it all leak proof and i ended up going the copper route. it wasn't too bad sweating the pieces together, i used the fittings with the solder already built in so it just required flux and heat. so thanks guys for all your help. i built it pretty similar to rambo's setup. lastly, what psi's should i run before the piping and after the piping for best water filtration and paint work?
 
#23 ·
I put a coat of paint on and i had some problems. Maybe you guys can help some. I figured out after I painted that I added too much hardener, it called for 8:2:1 paint:reducer:hardener and i put in 8:2:2. But, what happened is I painted the enamel and there are tons of "craters" in the paint. Could this be caused by too much hardener, or is it perhaps another story? I had the piping set up but caught no water. I had two back to back filters at the gun so i doubt there was any water. Might I also add that I put a heavy coat of paint on since it was on a flat surface so no running was an issue. Otherwise, it looks shiny and good but the craters don't work for me.
 
#24 ·
Are you painting parts for the car or a test panel?

If its parts for the car you will want to take the paint off. Too much hardner will make the paint brittle and that's no good to paint over again.

The symptom you describe sounds like fish eyes - mostly caused by contamination on the surface. What did you wipe it down with before applying paint and what method did you use?
 
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