Air compressor basics - help needed

Newton

Newton

AzB Silver Member
Silver Member
Typically me I spend normally a lot of time investigating things before I decide to
buy something. It includes functionality and how things should be done.

Now my wife has bought me a air compressor for Christmas and I have not had the time to use it
and of course not done any pre-work before any thing was bought...
However I did a small test run during Easter and it is obvious that it's a good machine
but it has a small tank.
The machine delivers 218Litre/Min of air (2.5Hp) but the thing is that it has just a
20L tank.
So it's kind of small but the amount of air/min is OK.

Now for doing normal cleaning of machines and possibly cooling when coring
this machine is OK, but for spraying I have my doubts.

Since it's hardly tested I'm amble to return the machine and swap to a $1000 big
brother which is a 3Hp - 435Litre/Min - however still only 20 litre air tanks (2x10Litre).

The question I'm chewing on is : Is their any point changing/upgrading since the
tank is still so small?
I was also wondering if there is any point of buying a larger tank to attach to
my current machine or it's bigger brother? Like a 30-60L tank which acts like a buffer
between the compressor and the equipment I'm using??

I have not had the time to ask Mr.Google to much - so I thought I could check
with you guys which most likely has been using your machines for quite some time...

Any comments would be appreciated.

Kent
 
Yes and No

If you know the consumption of the air tool then compare it to your compressor's out put. If the tool consumes about the same as compressor's out put the compressor will be running most of the time. The larger hp compressor will recover faster. Adding tank capacity helps by not having to hear the compressor run all the time.

If your tool, such as sander (DA or board sander), uses more air that the compressor's output, you end up waiting for it to catch up. Generally jam guns don't take much air.
 
You need to find the air requirements of your spray gun. Your compressor should produce more than your gun requires. It sounds like you have a construction/ nail gun type of compressor whichis usually used to produce air intermittently, such as for nail guns. I assume you are going to be using a mini-gun or A detail gun which do professional jobs with a lot less air than big guns.

A bigger tank is nice but I have been spraying for 35 years with 20 gallon tanks and 2-3 hp compressors. The $1,000 is a lot for a compressor. More than double what I ever spent.
 
Paul Dayton said:
You need to find the air requirements of your spray gun. Your compressor should produce more than your gun requires. It sounds like you have a construction/ nail gun type of compressor whichis usually used to produce air intermittently, such as for nail guns. I assume you are going to be using a mini-gun or A detail gun which do professional jobs with a lot less air than big guns.

A bigger tank is nice but I have been spraying for 35 years with 20 gallon tanks and 2-3 hp compressors. The $1,000 is a lot for a compressor. More than double what I ever spent.
Click to expand...

Paul, your spot on regarding the compressor-it's a high quality nail gun compressor- both of them.
Remember though that the tank is only 20L=5,3 US gallon tank which is i mini me
of your 20...
My better half has shelled out quite a bit of cash for the one I have, so I Xpect it's decent stuff.
The spray gun I have is on the borders of the machenes capacity- so this is the biggest reason for considering the biger brother. But then it has only 5,3 Gallon tank as well, but higher capacity.
I for sure dont plan any sanders or what ever on this thing, I only would like to shoot clear and keep my temperatures under controll while coring...

So I guess buying a larger tank and hook this would not work?

Thanks guys for taking U're time.

Kent
 
Hi,

It's all about CFM. With that small receiver tank, coring will take a long time. If you can get a 30 or 60 gallon receiver tank and mount it downstream of the tank you have now you can build up reserve capacity ( volume ) to get some work done without having to wait for the little tank to build up volume while doing a job.

As long as your compressor meets the PSI requirements for your applications, the volume tank can be filled before you do the work. Basically you are storing up the volume and PSI potential you need before you start the work.

Eventually you will need a big compressor if your shop grows. For now try to find a 30 or 60 gallon receiver on Ebay or Craigs List for cheap. You will always have a need for it even if you get a bigger unit later.

Good Luck,

Rick
 
Last edited:
scdiveteam said:
Hi,

It's all about CFM. With that small receiver tank, coring will take a long time. If you can get a 30 or 60 gallon receiver tank and mount it downstream of the tank you have now you can build up reserve capacity ( volume ) to get some work done without having to wait for the little tank to build up volume while doing a job.

As long as your compressor meets the PSI requirements for your applications, the volume tank can be filled before you do the work. Basically you are storing up the volume and PSI potential you need before you start the work.

Eventually you will need a big compressor if your shop grows. For now try to find a 30 or 60 gallon receiver on Ebay or Craigs List for cheap. You will always have a need for it even if you get a bigger unit later.

Good Luck,

Rick
Click to expand...


I was going to say the same thing. I see large stand up compressors for really cheap on craigslist, many times under $200, but I'd say for $500 or less You can find a really good compressor on there. I've passed up many deals for lack of space to store them. I have 3 compressors, and they are all portable units. They suit My needs for now, but would like to get a really nice unit one of these days. The Ridgid that I have doesn't seem to bad for what It is. Very Large motor, but the tanks could be bigger for My needs. Still The compressors that I have get me by. I saw a decent little Speedair on craigs list last week that was setup for spraying cars, and they only wanted around $50-$75. It looked brand new. I probably should have picked that one up at that price.

Greg
 
The tank size is not really relevant. More important is the air delivery volume at pressure.
A secondary tank can always be added with a dryer in between to give dry air.
Often I see places with small diameter delivery lines and small couplers from the compressor, and then wounder why the delivery is not there.
If you are using alot of compressed air, a larger tank in the system means more time to get the system up to pressure, with a longer initial run time. But once there, the compressor does not run in short bursts all the time.
I have found that the 20 litre tank is enough when using the 1/2 inch supply line for everything I do.
The regulator is set to 85 psi and the compressor is between 110 cut off and 95 cut in.
Other devices that use low pressure, have their own pressure reg on them. Like the dust gun is at 40

Remember to make regular oil changes to the compressor, and add a decent air intake filter as well.Then it will last for a very long time.
 
Last edited:
The post above are spot on regarding cfm and tool size. I have painted boats with that size compressor and found them wanting.. For a small gun they would be fine though. DA's and the like use a lot of air as well. Maintenence is simple. Keep oil in it and drain the water from the tank on a regular basis. If you don't have some sort of trap system you will have water.... Whether that matters is up to u.
 
You must log in or register to reply here.
Back
Top