Need help with air supply for painting - garage setup

Evil_Fiz

Promoted Users
I have spent the better part of today searching here and elsewhere but did not find any info on point. I am admittedly "search challenged" so forgive me if this is a redundant post. This will most likely be the only paint job I will ever do.

My current setup is a follows:
- Compressor
220 VAC / 3 HP / 12 SCFM @ 90 PSI / 60 Gal / rebranded 2-piston single-stage Puma (Northern Tool NorthStar). The compressor outlet is 1/2" with a 1/2" ball valve at the tank outlet.
- Aftercooler (located between pump and tank)
-B&M transmission oil coiler with 1/2" NPT fittings and a shrouded 1500 CFM fam pulling air through the cooler. 1/2" NPT in/out water trap between cooler and tank. The plumbing is 1/2" copper tubing. The temperature at the tank inlet is typicaly ~10* F above ambient.
- Paint Both/area
Plastic sheeting hung from the ceiling near the perimeter of a 2 car garage excluding the door opening. I will be painting with the door open. The car will be placed parallel to the door.
- Due to space constraints, the compressor is located at the corner of the garage adjacent to the door.

The plan is to run a 50' x 1/2" Flexzilla hose from the compressor to a backpack-mounted filtration system. From the filtration system, I will run a 6' x 3/8" Flexzilla hose to a gun-mounted regulator using 3/8" high flow fittings. I know I need a water separator, a filter, and a desiccant dryer. For filtration and oil separation I am considering a Motergard M60 with 1/2" fittings. I saw here in another post that an Arrow 2 Qt descendant dryer is a good choice.

- What is a recommended gun-mounted regulator?
- What is a recommended regulator for the compressor outlet?
- What other filters/devices should I consider? I don't want to go crazy spending on equipment that will be used for this job and most likely not get used again (or very rarely).
- I value the opinion of the members on this site so your critique of my ideas is encouraged.

Cheers,
Emil
 

Evil_Fiz

Promoted Users
I would seriously question the CFM ratings on that compressor. 3 hp is half the horsepower I have on my 2 stage 80 gallon compressor that is rated at 15 cfm.
What are you using for a spray gun?
I have not purchased a gun yet but will most likely look for a 9-10 CFM gun to ensure I have sufficient supply. I know the better guns require higher CFM for better atomization but I am willing to settle for a decent gun that will do an acceptable job, I am a novice and first-time painter. I fully expect to have a less-than-perfect paint job that will require a fair amount of pain correction to look decent. I have no way of verifying the actual output of the compressor but I suspect it is not too far from what it's rated at, but that is just my uneducated opinion.

Do you know where I can find an HP to CFM reference? I know physics has limits.

-----
Emil
 

sprint_9

Rookie
A good basic list, I used a setup similar to this.

Any quality Milton or Motor Guard wall regulator with a maximum psi of at least 120.

A quality Milton or Motor Guard Filter/Moisture trap

Motor Guard M-30 or 60 Submicronic Compressed Air Filter

Motor Guard RG4049 1/4 NPT Spray Gun Regulator

I would also spend the money on a good gun. A good gun is worth its weight in gold, take care of it and when your done you can sell it if you dont want to keep it.

That compressor will probably be at it's limit being a single stage. It might be fine for panel painting, but a complete all over at once will probably be taxing on it.
 

chevman

Oldtimer
Just a suggestion. Eastwood has a roll on set of the right rollers and a tray to get the primer on, and you could use a touch up gun with your set up for hard to get areas. Once you have it ready for color, then get all the paint and reducers you need and take all that and the car to Maaco. They have a lot of experience spraying, they just use inferior prep procedures and very low quality materials. Its your least expensive way out.
https://www.eastwood.com/optiflow-roller-and-tray-kit.html
 

Evil_Fiz

Promoted Users
A good basic list, I used a setup similar to this.

Any quality Milton or Motor Guard wall regulator with a maximum psi of at least 120.

A quality Milton or Motor Guard Filter/Moisture trap

Motor Guard M-30 or 60 Submicronic Compressed Air Filter

Motor Guard RG4049 1/4 NPT Spray Gun Regulator

Based on this recommendation I did some searching and am planning on going with the following items and installed in the order listed:
- 1/2 in ball valve at the compressor outlet
- Flexzilla Air Hose, 1/2 in. x 25 ft, 3/8 in. MNPT - HFZ1225YW3
(From the compressor to a mobile air treatment cart - Will replace ends with 1/2" NPT fittings)
- Motor Guard RG4520 1/2 NPT Compressed Air Regulator
- Motor Guard AF4510 1/2 NPT Compressed Air Particulate Filter
- Motor Guard CO4515 1/2 NPT Compressed Air Coalescing Filter
- Arrow D12-04XL Desiccant Dryer/Filter, 2 Qt, 1/2"
- Flexzilla Air Hose, 1/2 in. x 25 ft, 3/8 in. MNPT - HFZ1225YW3
(From mobile air treatment cart to backpack mounted filter - Will replace ends with 1/2" NPT fittings)
- Motor Guard M-C100 1/2 NPT Activated Carbon Compressed Air Filter (mounted in a backpack) Do I need this or is the M-60 enough?
- Flexzilla Swivel Whip Air Hose, 1/2 in. x 4 ft. (1/2 in. MNPT Swivel x 1/2 in. MNPT Ends), HFZ1204YW4S (Will replace gun end with high-flow fitting)
- Motor Guard RG4049 1/4 NPT Spray Gun Regulator
- Gun (not yet decided)

Please provide a sanity check on my setup

I switched the fan on the aftercooler to a pull configuration and the tank temp is slightly above room temp after several cycles. Do I need to run a copper pipe cooling loop after the compressor or am I good with the setup listed above?

Thanks, and cheers,
Emil
 
Do you know where I can find an HP to CFM reference? I know physics has limits.

-----
Emil

You need to look at the specs of that particular compressor. Notice the stickers on my compressor below. The first shows the total CFM the compressor puts out is 18.9 CFM but that is not under load. Air delivery is 15.6 Cubic Feet per Minute at 100 PSI and only drops .4 to 15.2 CFM at 175 PSI.

Another critical aspect is the RPM which on mine is only 1400.
The small HP compressors will often be running at more than twice that RPM in order to get the "ratings" they list. The higher RPMs generates more heat and will wear your compressor out much quicker.

You should also read the specs on your compressor to see if it has Duty Cycle rating. Some of them are limited to only 6-9 on/off cycles per hour.
P1010007.jpg

AirCompressor2.jpg


If you want physics go here: http://www.truetex.com/aircompressors.htm
 

Chris_Hamilton

Trying to be the best me, I can be
It's really not that complicated. In addition to '68's excellent advice about compressor size and cfm, I'll try to simplify things for you a bit.

First I'll describe my system, which had been rock solid reliable for me. This is for my small home shop.
7.5 HP 24-25 cfm IR compressor. Knowing what I know now I would have opted for a more expensive compressor that runs at a lower RPM. That being said the IR is reliable and has a 100% duty cycle. Previous IR I bought in 2001 for a Shop I had 20 years ago, stayed in the Shop after I left and lasted for almost 15 years of very hard use.

Around 50 feet of 3/4 copper pipe. Due to the small size of my Shop, I had to run it vertically up and down the wall in order to get the 50 feet of lenght that you need to have to cool the air down (assuming no aftercooler). I put three 3/4" ball valves at the bottoms of the piping runs to drain any condensation/water.

My system looks exactly like this with the exception of the pipe running up and down to get the 50 foot length needed before your first outlet.

So all you need for filtering are three items in this order,
Water coalescer,
Oil coalescer.
Dessicant dryer.
Follow this with your regulator.

Here is a pic of my setup. At the regulator the outlet is 1/2" so I have an adapter for the hose.whivh is standard 3/8" with 1/4" npt fittings.
The first two filters are Devilbiss Cam Air which I got at tooltooia. They still sell it. All you need for one person. I'll post a link.
I then added a 2 quart Arrow dessicant filter as seen in my pic. You can find a link to the Arrow at Zoro Tools here on this site. I'll post a link to that as well

20211124_204147.jpg
 

Chris_Hamilton

Trying to be the best me, I can be
Devilbiss Cam Air

Arrow Dessicant thread
 

texasking

Promoted Users
Another option to consider is a refrigerated dryer. Where I live, the desiccant dryer without a refrigerated dryer before it, becomes a maintenance nightmare. I tried everything after my last IR dryer died (after 18 years of continuous use) and finally gave up and bought a new one. Little to no maintenance and dry air, always. Used ones can be found very reasonable, or a new Harbor freight dryer is around $400, and works fine.
 
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Evil_Fiz

Promoted Users

@'68 Coronet R/T

Thanks for the info. My compressor does not have a similar label and the manual does not list motor or pump RPM. The current replacement model on Nother Tool's site lists the motor RPM at 3450 and the pump RPM at 920 which is close to what I remember for my compressor. I independently found the same link you provided and calculated my SCFM to be around 9. I spoke with Barry at length about my project and plans and he gave me several options for success.


@Chris_Hamilton

I ordered the Arrow dryer from ZORO.COM after reading your post on the subject.

Around 50 feet of 3/4 copper pipe. Due to the small size of my Shop, I had to run it vertically up and down the wall in order to get the 50 feet of lenght that you need to have to cool the air down (assuming no aftercooler).
Since I have an aftercooler, are you saying I can get away without the copper pipe loop, or do I still need one albeit shorter?

So all you need for filtering are three items in this order,
Water coalescer,
Oil coalescer.
Dessicant dryer.
Follow this with your regulator.
Is this unit what you refer to as a Water coalescer?
Motor Guard AF4510 1/2 NPT Compressed Air Particulate Filter

Some of the filters I am looking at are rated for a lower working pressure (usually around 120 PSI) than the 135 PSI my compressor puts out. Can I still get away with putting the regulator after the filters? I will be using a gun regulator as well.

In your opinion do I need a filter after the dryer? If so should I use the Motor Guard M-C100 or the M-60?

To all that have replied, please forgive my numerous questions.
The problem is that "I don't always understand all I know about that".

------
Emil
 
Like Chris, I have 3/4" copper piping running zigzag across a 12" length of wall to cool the air.
Then I saw a Refrigerated Drier for sale on craigslist that would handle 100 cfm airflow. It was like brand new and only $200 so I grabbed it.
Speedaire.jpg


I put a large Wilkerson M30-06-S05 pre-filter inline before the drier:
Pre-filterWilkersonM30-06-S05.jpg


It's really overkill for me living in Arizona but comes in handy during the Monsoon season when humidity levels are high.
 

Evil_Fiz

Promoted Users
Can anyone provide feedback on my previous post? (quoted below)
I am trying to make sure I understand the terminology and requirements in an effort to avoid buying the wrong products. In particular, I am unclear on the use of the term "Water coalescer".

-----
Emil

Begin previous post
Around 50 feet of 3/4 copper pipe. Due to the small size of my Shop, I had to run it vertically up and down the wall in order to get the 50 feet of lenght that you need to have to cool the air down (assuming no aftercooler).
Since I have an aftercooler, are you saying I can get away without the copper pipe loop, or do I still need one albeit shorter?

So all you need for filtering are three items in this order,
Water coalescer,
Oil coalescer.
Dessicant dryer.
Follow this with your regulator.
Is this unit what you refer to as a Water coalescer?
Motor Guard AF4510 1/2 NPT Compressed Air Particulate Filter

In your opinion do I need a filter after the dryer? If so should I use the Motor Guard M-C100 (carbon filter) or the M-60?
 
I have a couple questions myself. Any issues I have I know are moisture related. Trying to dry my air up. I’m going to install an aftercooler and water separator with auto drain on compressor. I hear that will help a lot. So, after that a majority of water has been removed from tank. Can I run right into a refrigerated dryer? Filter before or after dryer? I also need a couple full pressure outputs for tire machine, air tools etc so a regulated clean line would come after them. Any input? Also, I was stuck between desiccant and refrigerated unit. I’ve had desiccant in the past. As mentioned a maintenance item. Thought I’d use the dryer. Do these need to run 24/7 or do I turn them on in the morning and off when I leave? Thanks!
 

Dave C 5

Member
I run desiccant filter after my refrigerated dryer - bought the harbor freight one for $350 on sale - all problems solved ! Zero moisture now ! Tried all kinds of filters and set ups but the refrigerated dryer fixed it . The desiccant filters worked but I was going through 2 every paint job at $50 bucks a piece and maybe even 3 if it was middle of summer - turn it on when you go to the garage and off when you leave
 

Evil_Fiz

Promoted Users
I'm doing a final sanity check here before I buy my air supply filters.

Based on the recommendations I received here I currently have the following items in my amazon shopping cart:
- Motor Guard AF4510 - 1/2 NPT Compressed Air Particulate Filter
- Motor Guard RG4520 - 1/2 NPT Compressed Air Regulator
- Motor Guard RG4049 - 1/4 NPT Spray Gun Regulator
I already have:
- Arrow Desiccant Dryer/Filter, 2 Qt, 1/2"

Questions:
- Am I good to go with only the above or should I also get the "
Motor Guard M-C100 1/2 NPT Activated Carbon Compressed Air Filter" to put in a backpack just before a 4' whip to the gun?
- If I don't need the M-C100 for the paint line, is it a suitable filter to use with a DIY fresh air delivery system using the Allegro Industries 9910-D Tyvek Hood, a pancake compressor, and a non-gassing hose? (Based on the thread: My ~$100 Fresh Air Hood System" by Dean Jenkins)

Thanks again to everyone for all the help you have provided thus far.
-----
Emil
 

Chris_Hamilton

Trying to be the best me, I can be
I wouldn't use the whip hose. It will act as a restriction. Just connect your hose to your regulator. Use high flow fittings at the gun end
Your list looks good. Water coalescer, oil coalescer, dessicant , then your regulator. You would not need the activated charcoal filter in your air line. They are generally for purifying air. So yes it should work for a air purifying respirator. I'm not an expert on that though.

Remember to that you will need to run hardline of some sort from your compressor to the filters. 50 feet is a general rule. 3/4" is the minimum size. You need to include multiple water traps in the line as well.
I can post some pics if you need me to.
 

Evil_Fiz

Promoted Users
Thanks for the information, Chris.
I wouldn't use the whip hose. It will act as a restriction.
10-4, No whip or M-C100 needed

...Use high flow fittings at the gun end
Your list looks good.
I have the following on the shopping list as well:
- Milton 1/2" MNPT G Style Coupler and plugs
- Milton 1/4" NPT V Style Coupler and Plugs
- Flexzilla Air Hose, 1/2 in. x 50 ft, 1/2 in. MNPT Fittings. (This will be cut in half with new ends added; one half between the compressor and filters on a rolling caddy, and the other between the filters and the gun - reduced to 1/4" V Style fittings at the gun end.)

Remember to that you will need to run hardline of some sort from your compressor to the filters. 50 feet is a general rule. 3/4" is the minimum size. You need to include multiple water traps in the line as well.
I can post some pics if you need me to.
I have an aftercooler and water separator between the pump and compressor tank that bring the charge down to ~10* above ambient temperature. Do I still need to add the copper cooling leg? (60 Gal,/3HP compressor running at low pump RPM - about 9-10 SCFM actual flow)

-----
Emil
 
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