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Desiccant dryer and oil separator?

#1
I have a 2-stage compressor with a refrigerated air dryer. They are connected with 1/2" pipe and hoses to a regulator/water separator. This feeds my 3/8" hose reel.

Just to be safe for painting I want to add a desiccant dryer.

Few questions.

1. Should I also include an oil separator? My understanding is that a filter capable of capturing particles as small as 0.01 micron will capture oil. Any recommendations?

2. As I have a refrigerated air drier I don't feel I need a high end desiccant dryer. Any recommendations?

Thanks
 

Barry

Paint Fanatic
Staff member
#2
I'm a little confused (normal).
An oil colislester is most important as oil vapors will go threw ANY water filter and the desiccant as well as the refrigerant.
best buy i know of is Motor guard for about $50.
All you need is one or other system.
Also all filters want 15 feet of pipe from compressor for mounting.
 
#3
I know the oil vapor won't be trapped by the desiccant or the water filter, which is why I'm actually considering the Motor Guard filter.

Given I'm using a refrigerated air dryer the desiccant might be overkill, but I tend to be a little OCD on this stuff.

I don't have 15 feet of pipe between my filter and compressor. My understanding is that the point of the extra pipe is to allow the water to condense after leaving the tank and before a coalescing water filter. My refrigerated dryer does that for me. It has a coalescing trap inside it already so the one I have after it is probably redundant.
 
#4
ok an oil filter should be between your compressor and refer dryer to keep the oil out of your dryer and the rest of your plumbing. if your refer dryer is sized right then you dont need a desiccant dryer. i have been running a refer dryer here in nj with 90+% humidity every day for 12 years and i have never once had moisture in my lines or problems painting. what you should have is just a particulate filter in your booth or spray area to catch anything that might come from the interior surface of the plumbing. corrosion, etc.
 
#5
Depending on what Ref. dryer you have it might have a filter built into it. Mine is a Hankinson "HIT" (Hot, Inlet, Temp) it has a built in aftercooler and filters inside before it goes to the Ref. section, the filter will auto drain when needed. It is designed to be placed close to the compressor because of the aftercooler. Most others have some level of filtration before entering the Ref. section. and require more distance from the compressor due to the lack of the built in aftercooler. After the dryer I also have an oil separator mounted before the desiccant to help catch crap before entering the desiccant it helps with not loading it up prematurely. Then like Jim and Barry said a Moto guard in the booth area as a last ditch effort to catch the last bit of debris. Just remember with the Moto Guard filter "DON'T USE A ROLL OF TOILET PAPER", you wouldn't wipe your butt with Moto Guard filter paper so don't use toilet paper in a Moto Guard. You wouldn't believe how many people use toilet paper in a Moto Guard because they are the same size and I just shake my head.

There are some other high end filter systems that cost an arm and a leg that can do better (in the ultra microns) but there is no need to go down that rabbit hole (I almost went down there just to see) when for this purpose there would be no benefit.

Doing it the ways mentioned you will have no more worries that it's because of your air supply.
 

Barry

Paint Fanatic
Staff member
#6
I was not referring to the m60 i think the number is for motor guard tolet paper one.

I was talking about the oil seperator with nylon filter inside.
Other than that bunch of good advice here.
 
#7
Thanks everyone. LOL on the toilet paper roll comment. I have never dealt with this type of equipment before, but I would think anyone with half a brain would know TP makes no sense. No filter prior to the cooler. Just a filter/water trap inside after the cooling take place.

Good call on the filter prior to the dryer. I have nothing but a hi-pressure hose from a regulator on my compressor tank direct to the refrigerated air dryer. After the dryer is a Speedaire regulator/filter/water trap. I was going to place the Motor Guard M60 after that. I think I should move the Speedaire to the tank eliminating the first regulator and placing the filter prior to the dryer. Then after the dryer I can place the Motor Guard for final filtration. At the gun I can use a small filter/desiccant trap as a final precaution.

I plan on adding an after cooler after the compressor and before the tank to help prevent moisture in the tank itself. This is to protect the tank from rust. Right now however I just want to produce clean dry air for my current project.

Make sense?
 
#8
One more thing get yourself an electric automatic drain for your compressor tank. They have a timer for setting how long between each time it drains and also a timer for how long it will drain. well worth the money, no need to worry if you drained the tank or need to.

https://www.ebay.com/itm/ATD-Tools-...826508&hash=item35eebf0065:g:3FgAAOSw9N1Vkh04

This is like the one I have on my compressor. There are others you my find better suited for your use but this one I have had no issues with at all.
 
#9
hey ! i use terd paper in my motoguard. recycle man ! an oil filter first out of the tank to keep vapors in check , refer to remove moisture then in my booth i have a small vapor trap/moisture trap then a reg .

but seriously i have used cheap truck stop terd paper in moto guard for over 30 years . i start fresh on every paint job . i also use to buy the brown hand dryer paper and cut the roll in half .
 
#11
The issue with using TP is it produces lint because it is soft and that it is designed to break down in water/septic tanks and with that if there is any moisture in the lines including oil over time it can break down and pass lint thru your lines that and it is not as tightly rolled as the filter is which can lead to letting oil and such pass thru your lines. So for me I use the filters, given that these jobs are not being painted 3-4-5 cars a day they will last quite a long time. No sense running the risk IMO for $30. Others have had no issues either so long as they remembered to change them more often then the proper filters.

Just my 2 cents.
 
#12
ever gone in a mcdonalds ? aint nothing soft about it :(. i use commercial grade . i like the paper towels the best . it gets changed every session .
 
#13
the other issue with tp is there is chemicals in it. not sure what, probably salts of some kind when processing the paper but it causes extremely bad corrosion inside in filter housing. shine might not get it if he changes the paper out every time and removes it as soon as a job it done but if you leave it in there it will corrode and pit the aluminum like crazy and rather quick.
 
#14
my first mcguard filter back in the 70's corroded bad. i used their filters and changed monthly. running a lot of vans then . when i get moved i will blast my filters and epoxy them. the cheap powder coat on them does not hold up well . my air for the booth will be separate from the rest so it will get little use .
 
#15
So sorry if I offended. Very surprised to hear a painter would use TP given exactly what Datec and Jim C said. I'm a novice so what do I know. My apologies.

Thanks for the advice though. Greatly appreciated.

The Motor Guard is a 0.01 micron filter. I have read it's important to run a larger micron filter prior to it to grab the larger items and prevent it from clogging quickly. My Speedaire regulator filter has an element with the number 40 on it. Does this mean it traps particles larger than 40 microns? It's an older unit, model 6ZC29A, and I can't find any specs on it. It's mint and appears to work great. The element is almost pure white so I suspect it's serviceable. Not even sure how to find a replacement and none of my searches produced any results for this model.

That all said, the speed air should come first followed by the Motor Guard and then the refer dryer. at my gun I plan on using a small filter/desiccant device. This will protect my dryer and provide clean dry air for painting. Make good sense?
 
#16
So sorry if I offended. Very surprised to hear a painter would use TP given exactly what Datec and Jim C said. I'm a novice so what do I know. My apologies.

Thanks for the advice though. Greatly appreciated.

The Motor Guard is a 0.01 micron filter. I have read it's important to run a larger micron filter prior to it to grab the larger items and prevent it from clogging quickly. My Speedaire regulator filter has an element with the number 40 on it. Does this mean it traps particles larger than 40 microns? It's an older unit, model 6ZC29A, and I can't find any specs on it. It's mint and appears to work great. The element is almost pure white so I suspect it's serviceable. Not even sure how to find a replacement and none of my searches produced any results for this model.

That all said, the speed air should come first followed by the Motor Guard and then the refer dryer. at my gun I plan on using a small filter/desiccant device. This will protect my dryer and provide clean dry air for painting. Make good sense?

No offense here as I'm sure that goes with the others too. It's all good.

Anyhow.. I don't have any filters before either of my ref. dryers with the built in filter I let that do the first round of filtering after that is where I have the other filters with the motor guard placed in the painting area with the painting hose attached there. I'm not so worried with the air lines that run the air tools, I see no need to over kill the filtration for that, but for the booth that is where you would really want the cleanest air you can get and afford to do. Like I had said in the previous post it can turn into a rabbit hole getting clean air. Here is what I almost bought for my painting area.

http://www.spxflow.com/en/hankison/pd-mp-dhw-series/

My compressor guy, that I have been dealing with for 27yrs, always jokingly calls me a d@#k head for always over thinking and over killing everything. He talked me out of it saying that is so much over kill It's retarded. My thought was if anything goes wrong you can't blame me or my equipment...

Back on track. I have been running no filtration before the dryer for years and have had no issues with build up in it but that's not to say having one before is wrong just that you might be changing or cleaning it more often.

As for filtration yes going from a larger filter to a finer filter would be good if you went straight to a fine filter it would clog faster then it should.

Depending on your budget, Hankinson makes some of the best with a huge choice of filter choices from large particles all the way to ultra micron filtration. There are other notable choices that do a great job also that will provide you with great results and no worries. SMC would be another good choice.
 
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#17
Your guess at 40micron would be my guess also. I myself don't think I would use it just because of the newer better units offered in today's market. That and the modular units are really nice, just connect them together and you have all the progressive filtration from large to fine in one location all connected to one another with pressure regulation.
 
#18
I've corroded out a Motor Guard 60 from leaving a water saturated roll of paper ( the filter) in the housing for too long. Ate through the black internal coating and destroyed it.
 
#19
Im on my second one as well. Since I only use it when painting the original sat for awhile with a damp roll. I have better water separation now but I still remove bottom when not in use
 
#20
when you get a new one epoxy the crap out of it. they are cheap pot metal and the coating is junk . i have a friend that is a stainless wizzard. he is making one for me .
 
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