Shop compressor air dryer for DIY resto projects

Schroeder

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i know there are multiple threads on this. I have done my searches. The ones I was most interested in are out of date by a couple years though, so I wanted to make sure that the path I am going down is still good and valid. I am looking at two options.

#1- run 3'-4' of copper line from the compressor head into a B&M trans cooler or an AC condenser. There would be an inline water drain here at the condenser's exit that could be an electric/automatic unit. After that I'd run copper line out of the condenser to a motorguard m60 filter and then the standard water separator/regulator/oil separator set up. This would then feed my hose reel and at my paint gun I'd have a little online filter. I might get fancier by having a manually activated/switched fan over the condenser for increased cooling, heck, maybe it would be automatic set to run whenever the compressor ran. I'm guessing this would cost ~$400.

#2- run a line directly out of the compressor to a motoeguard m60 filter, run this to a HF refrigerated dryer, replace its drain with an automatic electric unit, run the line from the HF unit to a standard air separator/ regulator/ oil separator unit, and finally have a little in line filter. This probably is gonna be closer to at least a $700 charge.

Is the HF unit still good? There isn't any recent chatter about in on the internet over these forums. The only recent thing I have to go off is the HF reviews on their website.

I have a single stage 6.5HP 60gal compressor.
 

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Most guys here are using a bigger compressor. If you are going to do more painting in the future, save up $ for more air CFM. Otherwise, the recovery time is going to be slow on a big spray job. Faster recovery time = longer air cooling time. That makes it easier to get dry air. Water vapor can not be removed from the air 100% until it cools to the dew point (cooler than ambient air temperature).

If the air is already dry before the gun, I have read here that inline filters are not worth using. Otherwise, they don't last long before they are contaminated. I don't use them anymore, because I now have dry air. Before investing in dry air, I used to get little pimples in the paint from some kind of spatter. I wondered if it was water coming through after the line filter was saturated.

I can't give you feedback on on your options, but I would lean towards a refrigerated drier to capture the most water vapor possible. I may go that direction in the future. Currently, I run a 3/4" filter/regulator off the tank, then 3/4" x 20' copper coil through a 5 gal bucket of cold water. Then through a 3 gallon expansion tank, M60 filter. The expansion tank collects the water, the M60 filter is always bone dry. But, I live in a dry area usually 50% or less humidity. So far, I have not done any painting since upgrading my air supply, so I can't give feedback yet. I have done some blasting, and as far as I can tell, I'm getting dry air.

It is a slippery slope on upgrades. Truth is, most DIY'ers don't have a proper air supply, you're on the right track. Dry air is expensive $!
 
I have a Hankison HIT35 refrigerated air dryer (best unit on the market) after my compressor then it goes into another filter regulator which collects nothing because the air dryer has filters built into it and does an outstanding job. The HIT stands for "high inlet temp" which means it can handle the high temps that come out of a compressor that has been worked for extended times. Single stage compressors work harder then 2 stage which means they run hotter and pass more oil. HIT's also have a built in after cooler with fan before the refrigerated stage which cools the air to ambient air temps (very important).

If I was you I see a couple new HIT20'S on Ebay for around $450, I would grab one of those and not look back you will have nothing to worry about after you get one. I would also install an electric timed auto tank drain to your compressor too.
 
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MX442, I like your method. Any idea on how much cash you got in your setup? I'm guessing the m60 is the most expensive portion of your investment, and they're only like $75. I have higher humidities (at times) than you being as I'm in NW Ohio. If you have such good luck, maybe I just need to go that way. It seems like the guys who have made similar setups all have very good luck without taking the refrigerated route.

DATEC, the $450 unit I see on eBay right now has all kinds of disclaimers on it and caveats along with extensive warnings that he doesn't take returns and hasn't tested the united. The listing doesn't give me a warm feeling. I will have to pass on it, but I really appreciate you teaching me about a good brand to look out for!

My compressor may not be a professional grade unit, but it should feed my iWata LPH400 which requires 9.5CFM at 29psi if I remember right. I do have horrible moisture problems though. After the compressor runs awhile I get TONS of water spraying out my die grinders and other tools. I've been ready to paint some parts in epoxy for a couple weeks now and have had to find other things to do on my project, because I am aware of this water issue and haven't decided how to address it. I don't know how important it is to have perfectly clean epoxy, especially since what I'm painting are interior panels that are only binge rust-proofed, but I figured I may as well do all of it "the right way."

I kick all these ideas around and typically I just end up flipping a coin of sorts and just picking one. I think I'm gonna go the cheaper route with this. It seems this route gets the same results as going the expensive route, and yes, I may do another car....in 15 years. The need for perfectly clean air is NOT typical for me. I am a farmer and use the air all the time, and while clean, dry air is great to have, I don't NEED it EVER. This project is the only time I have been sand blasting and painting quality paint. So if I can get away by doing this clean, dry air setup at a DIY budget, I think I'd be best off.

With all that said, since you guys have pointed out that I may have additional oil problems with a single stage compressor, would it be in my best interest to invest in two m60 filters? I could have one right out of the compressor. Next the line would go through a condenser or small trans cooler. I'll probably set up a fan to blow over this. From the trans cooler I'll run the air through 20'-30' of coiled up copper tube in a 5 gallon bucket of water. Out of the bucket of water and coiled copper tube I'll run into an expansion/ dryer tank. This tank will just be an old portable compressed air tank I have laying around. This tank will have the water drain on it. It will be a manual drain if I have this whole system setup on a bypass leg for times when I need the super clean and super dry air, and it will be on an electronic, auto valve if I decide to leave the whole system permenant as part of my day to day setup. From here I'll go into the actual compressor 60 gal tank. Out of the tank will be an additional m60 filter. After this filter the line will feed a standard regulator. Out of the regulator will be the line to my paint gun. I'm gonna keep an inline filter at the gun when I first use this setup to make sure it's working 100%. How's all that sound?

On a side note, should I remove the manual petcock drain on the bottom of my compressor tank, which I believe to be rusted shut, and replace it with an auto valve if i don't keep the whole system I described above in the normal loop and bypass the said system?
 
Mustang408, thanks for the reply. I have seen those in line filters. I guess I wouldn't rule them out. I was looking for something a little more robust I think though. Somewhere in between your solution and a high end refrigerated dryer. How long did your inline filter last? How do you know when they're bad? Do you just pop an end off and look at the desiccant? From the little I have heard of them it sounds like they don't last that long.
 
I thought you were just looking for something to use for one car.
No, they don't last long.
Good for doing a single car. The M60 gets everything if the filters are kept changed.

I have 20 feet of 1" copper pipe before my M60 on my shop side(not the paint booth) and using a DA will overwhelm the paper element in a couple hours of continuous use.I don't have a particularly good 80 gallon 2-stage compressor, but if it runs continuously from heavy use it naturally produces a lot of heat/water and my length of pipe no longer works to condense it.

For my paint booth I have 35' of 1"copper to this: https://www.amazon.com/ATD-Tools-7888-5-Stage-Desiccant/dp/B000YOSLE4
Never had any problems because all I use it for is small stuff and a car or two a year, spraying only.

I personally wouldn't want all the complexity you talk about setting up.
Just get the HF refrigerant dryer with a M60 hanging off it before your hose and do some painting.

My 2 cents
 
I think may be complex but I think it will achieve the results of your $450 system, at half the price. How long does your desiccant last in that? So you don't run your DA sander off that system? If you did, do you think it would really eat through the desiccant. All my work done on my car will probably go through whatever system I come up with: sanding, sand blasting, painting, grinding metal and welds, etc. the farm work may go through a bypass, but right now I would have to say this system would see about 16 hrs of use. With your $450 system will I be eating m60 filters and desiccant like crazy?
 
I think may be complex but I think it will achieve the results of your $450 system, at half the price. How long does your desiccant last in that? So you don't run your DA sander off that system? If you did, do you think it would really eat through the desiccant. All my work done on my car will probably go through whatever system I come up with: sanding, sand blasting, painting, grinding metal and welds, etc. the farm work may go through a bypass, but right now I would have to say this system would see about 16 hrs of use. With your $450 system will I be eating m60 filters and desiccant like crazy?


You will kill any temporary fix doing all that. You will burn thru desiccant and slaughter an m60 filter. Look into getting at least a fan cooled after cooler (Ebay, there is nothing to worry about not working) mount that after your tank put a drain after that to remove the moisture, then you will have cooled the air down to ambient temp. Then put an oil separator in line from there do your work, use the m60 only for painting that way you have nothing to worry about getting into your paint.
Your best and easiest choice will always be a refrigerated dryer, there are other choices that will do the job if your not wanting the top of the line, but you want one that does hi temp.
 
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You will burn through paper filters and desiccant by using that as a primary water/oil filter for doing all the work. At that point the cost of replacing the filter material you would be better off just gating a dedicated dryer. Those items will be stopping all the water and oil which would fill them quick.

The cooler looks like that but that fan is 12v, you need a 120v fan, and while people have used them for air cooling they are not rated or made for that.
This one is (linked below). you mount it to the tube going to you tank from the head and mount the other end to your tank. That will allow the air entering your tank to be cooled dropping 75-80% of moisture to the bottom of your tank, that is where a auto tank drain comes in, spitting the moisture out. Now your entire tank air is cooled to ambient temp.

http://www.ebay.com/itm/UNIVERSAL-A...605827?hash=item3f452e5c43:g:K5UAAOSwCU1Yvaau

The above example is called a compressor mounted after cooler which is also a good way to go. The one I was referring to is a little more expensive with a dedicated 120v fan mounted after the tank.

http://www.ebay.com/itm/AIR-COMPRES...585832?hash=item41abd2b028:g:fxYAAMXQDK1RwzgO

They are not as big as they look in the pic. The one I linked is a large CFM unit that would be way over kill for even my needs. The first link would be the better choice at getting most the moisture out and would take up no floor space because it mounts to the compressor and it uses your pumps pully as a fan but if you like you can mount an external fan if you like, the more air flow the better. Atlas Copo sells them also. They all do the same thing and no parts to break.
 
My first compressor in a home shop was a 60 gallon 6.5 HP Single stage. While not ideal I did quite a few cars with it and it performed like a Champ.
I totally agree with DATEC but I will present you with a poor man's alternative. First with the size of your compressor no need for anything larger than 3/4" piping provided you are not going over 100' in piping. Copper throughout would be ideal but other materials will work as well (galvanized pipe black iron, even PVC provided you cool the air enough.) I have done this in the past and it worked nicely, not as good as a refrigerated dryer but I had the materials so it didn't cost me hardly anything. Get a 50 foot coil of 3/4" copper tubing. (copper has gone up so this may end up costing almost as much as the $450 dryer) make your run out of the compressor and to the direction you want the piping going. Join the 3/4' coil but have the coil in a bucket or tub (I used one of the plastic storage tubs you get at wal-mart) Re-join the coil to your piping and continue your run to your filters and outlet. Fill the tub with cold water, I cut a hole and bonded a drain plug to mine so I could drain the water and refill. Hot days I would use some ice. Like I said not the equivalent of a refrigerated dryer but it does the job in my home shop with a IR 7.5 hp 2 stage compressor. Cools it enough that I get very little condensate downstream even in the hottest most humid months here in Southern VA. And it allowed me to use PVC the rest of the run. I rarely have to change my filters.
Oh and don't forget to install a drop with a ball valve right after the coil to allow the condensate to drain.
 
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Chris, I already have delivery lines ran through out the shop. I think they're all 1/2". You're saying just the copper coil has to be 3/4"? Your point of the drain brings up a big question I was pondering all day yesterday after I wrote my long response here. How does elevation play a role in the system's setup? I would think that the cooling tank would have to be elevated and the end of the copper coil would have to come out of the bottom of the tank and then loop back up to the rest of the system. In the bottom of the loop there would be a drain.

This of course isn't easy. The easiest thing to do is to bend the line so the loop ends up being in the tub of cold water. Then you have to bend the line back up and out of the tub. This means that the water stays in the line in the cold tub though, doesn't it?
 
I'm not usually a harbor freight fan but I do have their refrigerated air drier. my drier is about a year old and does a good job. It runs 8-10 hours a day 5-6 days a week, the only issue with them is the drain sucks. Mine's mounted over head so I just put a length of pipe in it with a ball valve, but I'm going to put an electric auto tank drain on it soon.
 
So just run right out of he compressor into the HF drier, from there into the compressor tank, from the tank into an m60 filter, and from that to my regulator? Since the HF unit is probably not a high temp unit and I will have higher temperatures coming out of my compressor since it is a single stage, do I still need to have 30' of copper coiled up in an ice bucket?

The question also still stands concerning elevations of these coils and their drains with respect to the rest of the system.
 
I'm away from home for a couple weeks, but I'll snap a pic when I get back. There are some real smart guys here that do this everyday, though in a professional shop they need to rely on professional solutions. But for a one time paint job, I think you may be able to get by with a copper/ice water chiller followed by filters. I'm not a scientist, but I do have a minor in meteorology. If I remember one thing from college, air vapor condenses to liquid at the dew point temperature. Therefore your air supply must be cooler than the ambient temperature to have any chance of "filtering" out the water vapor. I don't think a radiator type cooler with a fan would be as effective as ice water.

To answer your question about cost, I think the copper coil was about $60 plus fittings. M60 about $70, and the filter regulator was about $100. I already had the expansion tank, and I spent about another $30 in hoses to plumb it.
 
On the other hand, if you found a used refrigerated dryer, you could probably sell it for what you paid for it when you're done. With a homebuilt copper / filter setup, they're pretty much worthless when you're done.
 
On my set up I have my compressor on 80 gal tank outside under an awning then its plumbed through the wall and goes about 15 ft to a second 80 gal tank. from there it goes to a motor guard m800 system (which is a oil coalescing filter, a particulate filter and regulator good up to 120 cfm). I have that regulator set to 120 psi. after that regulator there is where my refrigerated air dryer is located. By having the dryer so far from the compressor and after 2 tanks I have already pulled a lot of moisture out of the air which allows the dryer to be that much more efficient. after the dryer the line splits one feeding my booth which still has a sharpe desiccant system hooked up but really doesn't do much any more, I just leave as a just in case. The other line feeds the front of my shop where I need air for air tools.
 
Just a reality check here; one drop of water on the roof of a car can easily ruin several hundred dollars worth of work , even if you aren't valuing your time well. Coincidentally, this is about the same kind of money that you will find entry-level refrigerated dryers going for.

If this is a hobby that you love, invest in it and reap the rewards of having better, more consistent results. These kinds of things pay for themselves on the first few jobs through peace of mind and pride of a job well done, with few preventable mishaps.

But if what you are doing is just born of the need to get things done as cheaply as possible, you might possibly be in the wrong place. Even the pro shops I used to work for knew that the best way to get a job done cheap was to detrim, do the body work and primer, and send the vehicle off to Maaco for paint. For that, you don't need much in the way of an air system at all, since primers aren't as picky about a clean air supply (except the epoxy).
 
Ok ok, you guys all make good points. I had another thought. What if I coiled up 50' 3/4" copper line, put it in a bucket of water, froze the bucket before painting or sanding, and then put it in line with my system. After the bucket would be a dip and a drain. From there would be the HF refrigerated drier. From there would be an m60 filter and finally my regulator.

Does that sound like a solid, done right setup? Is it enough filtration for oil? Again, as someone mentioned, I have a single stage compressor where oil may be more of an issue.

Yes, I like to explore the cheapest option, but I am NEVER against spending lots of money if it's the only way to do it right and purchase peace of mind.
 
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