air compressor volume

[crazy@7]

I have 2 electric air compressors both are about 4 to 5 CFM @ 90psi, one will not keep up with my hi speed die grinder, and I want to get a blaster gun. Does any know if I can plumb these 2 together and would I get more volume, would the result be worth the effort?
Also would it require check valves.

 

[Felineman]

Nope you need at least 40-50 CFM to run even a small grinder and at least 85 PSI preferably 100 PSI and 60+ CFM. For a sandblaster you need a min of 110 PSI and at least 80 CFM. I know this because my compressor is going out to have the reed valves done tomorrow.

 

[KartFab]

You can plumb them together, but DO NOT put in a check valve. I just used some rubber hose and brass fittings that i found at harbor freight. cost like 10-$20.

Two male quick connect fittings
one "T" fitting with threaded end
one female quick connect fitting
a couple feet of rubber hose

(I also put an air filter on the "T" fitting it because i used it with my plasma cutter, then made a female plug for one end when i used it with just one compressor)

 

[Poboy kartman]

Nope you need at least 40-50 CFM to run even a small grinder and at least 85 PSI preferably 100 PSI and 60+ CFM. For a sandblaster you need a min of 110 PSI and at least 80 CFM. I know this because my compressor is going out to have the reed valves done tomorrow.

WRONG.......just WRONG.......not even close. ....CFM's are measured in the single digits usually. ...a 9 CFM compressor @ 90psi...is one bad mo fo.......

And you can run anything on any compressor that can build the pressure. ...it's just a question of duration. .....

 

[KartFab]

I was going to say something, seemed a ways off, but I don't use air tools much. My plasma cutter runs between 80-100 psi @ 6 cfm. My little 4.5 cfm compressor runs for about 45 seconds until it drops below 80 psi.

I also have a 60 gal 3 hp 11 cfm compressor, never runs out of air, just can't take it with me when I do work out of my garage... What cfm do most air tools need? Duty cycle probably plays a big role (e.g nail gun vs paint sprayer)

 

[machinist@large]

Wait a minute; those #'s just don't add......

Nope you need at least 40-50 CFM to run even a small grinder and at least 85 PSI preferably 100 PSI and 60+ CFM. For a sandblaster you need a min of 110 PSI and at least 80 CFM. I know this because my compressor is going out to have the reed valves done tomorrow.

WHAT KIND OF GRINDER/ SANDER ARE YOU RUNNING?!?!?

At 40 to50 CFM at 85~90 PSI I can run a pretty nice medium size CNC machine shop, with over 20+ machines. Most CNC machines will list a needed CFM requirement, somewhere in the ~ 4 to 5 range, but that's only for short bursts, like tool changes, which tend to be 60 seconds or less. With the correct size piping, you would only need to worry if you had 10 machines the all changed tools at the exact same time, every minute.

The usual small air tools, like a die grinder, don't even really show up in the #'s, because they're only used for secondary tasks.

 

[Poboy kartman]

To put it in perspective: my compressor is rated at 4.0 cfm @ 90psi.......I can spray paint with it...but not for more than about 5 minutes, but I like a lot of air and pressure when I paint.

A die grinder is about the same. ....an impact less than a minute. ....a sandblaster about the same. ....nail guns all day long.

It's not new and doesn't put out nearly what it did new.....but it's biggest set-back is the fact that it doesn't have very big tanks. ...

It's a one hand carry compressor and it takes less than a minute to fully recover from 40 psi to 125 psi.

 

[crazy@7]

Wow

Wow...uh...80 CFM...Wow, A Chicago Pneumatic 15 hp, dual compressor, 200 Gallon tank, for $5,599.99 only gives me 50.5 CFM. I guess I will have to get 2 of them, thats only 11,000 and some change.

No really guys thanks. You think that will double the volume? It sounds doable to me. And really I dont have $11,000 dollars layin around. If I did I would have one heck of a kart.

 

[Poboy kartman]

And really I dont have $11,000 dollars layin around. If I did I would have one heck of a kart.

No......I would make a quick trip to S.C. and visit your house while you were sleeping. .....

 

[machinist@large]

Wow...uh...80 CFM...Wow, A Chicago Pneumatic 15 hp, dual compressor, 200 Gallon tank, for $5,599.99 only gives me 50.5 CFM. I guess I will have to get 2 of them, thats only 11,000 and some change.

No really guys thanks. You think that will double the volume? It sounds doable to me. And really I dont have $11,000 dollars layin around. If I did I would have one heck of a kart.

Just tee them together like Grant suggested, and pocket the theoretical savings.

No......I would make a quick trip to S.C. and visit your house while you were sleeping. .....

I would pay money just to see how you were going to load up a pair of 50 CFM air compressors into the back of your truck, all by yourself...... That could be rather entertaining.....

 

[Poboy kartman]

Just tee them together like Grant suggested, and pocket the theoretical savings.





I would pay money just to see how you were going to load up a pair of 50 CFM air compressors into the back of your truck, all by yourself...... That could be rather entertaining.....

Not the compressors.....the cash.....Even old and decrepit as I am I can still lift $11, 000....as long as it's not in loose change. ...

 

[Felineman]

I run a 76 CFM 240 PSI compressor at my new shop and it can run almost every tool at once and still keep up, mind you its also 550 volt. Single digit CFM compressors are useless for air tools and only good for 2-5 min use or airbrushing. Sorry I disagree with you all I have use compressors for about 25 years and the more CFM the better so you don't run the compressor part constantly. For single use compressor for private shop I would get something around 12-20 CFM. so your compressor doesn't run constantly. For professional use get 30-40 plus.

 

[Poboy kartman]

Ummmmmmm- Yeah.....this isDIY gokarts forum. ......and while some are "Doing It Yourselef" for the he77 of it. ...not many have the means to purchase a $1000 compressor just to run a hand-held tool.

You are right. .....cfms are like money, women, and big boy toys......there isn't too much. .......but there is reality and B.S.......and to quote Clint Eastwood......:"A man's got to know his limitations. ...."

 

[Felineman]

I see compressors around 20 CFM all the time in the buy and sell papers for 200 try criagslist and kijiji. Might need rings or reed valve but those are easy. Getting that size in 120 volt is the problem.

 

[Poboy kartman]

Wow...uh...80 CFM...Wow, A Chicago Pneumatic 15 hp, dual compressor, 200 Gallon tank, for $5,599.99 only gives me 50.5 CFM. I guess I will have to get 2 of them, thats only 11,000 and some change.

No really guys thanks. You think that will double the volume? It sounds doable to me. And really I dont have $11,000 dollars layin around. If I did I would have one heck of a kart.

Oh- sorry.....got carried away there......but yes......you should double your output and also double your volume which I barely touched on.

Psi and cfm are one thing. ....but volume is another. ...it's like a squirt gun.....it may shoot hard and fast. ....but only for a brief second.....while a scaled down water tower will deliver much less pressure.....but do it forever. .

In a perfect world. ...the compressor would make more CFM than the tool can use......in my world. it just takes a little longer to get the job done. .

 

[fowler]

if u have to use a 30cfm compressor then u might wanna look at your work style
the power bill alone

might is 15cfm
and its on the bigger end of what i need
the compressor has a 50lt tank which is its only issue
too small
only takes a minute or 2 so to fill it but the air doesnt last long

so i added the 90lt fire suppression bottle as another tank

takes 5 mins to fill both but then doesnt run for 10 mins while it drains them both

two 4 cfm compressors together will be fine
may require a bigger tank though

if u wanna talk real air compressors
then the ones for the drill rigs in the workshop across the road at work
tens of thousands of cfm
but threy require there own truck to get around

or really u want a rotary compressor
once u use a rotary u realize piston is very inefficient

 

[OzFab]

My big compressor is the biggest 240v unit I could find; 3.5hp, triple head pump on a 100L tank; it puts out 12CFM @ 90psi; I can run my sandblaster flat out @80psi & it keeps up so, a die grinder, air sander, drill, even a rattle/impact gun, no problem...

 

[machinist@large]

Oh, to live in the perfect world....

I run a 76 CFM 240 PSI compressor at my new shop and it can run almost every tool at once and still keep up, mind you its also 550 volt. Single digit CFM compressors are useless for air tools and only good for 2-5 min use or airbrushing. Sorry I disagree with you all I have use compressors for about 25 years and the more CFM the better so you don't run the compressor part constantly. For single use compressor for private shop I would get something around 12-20 CFM. so your compressor doesn't run constantly. For professional use get 30-40 plus.

Ummmmmmm- Yeah.....this isDIY gokarts forum. ......and while some are "Doing It Yourselef" for the he77 of it. ...not many have the means to purchase a $1000 compressor just to run a hand-held tool.

You are right. .....cfms are like money, women, and big boy toys......there isn't too much. .......but there is reality and B.S.......and to quote Clint Eastwood......:"A man's got to know his limitations. ...."

It's probably a good thing you live in another juristinction; in some parts of the world, preaching to the choir can get you in trouble. Kind of like people proving that the emperor has no clothes....

I see compressors around 20 CFM all the time in the buy and sell papers for 200 try criagslist and kijiji. Might need rings or reed valve but those are easy. Getting that size in 120 volt is the problem.

Really? You have just noticed that most members of the forum will most likely never have access to 3 Phase power?

My big compressor is the biggest 240v unit I could find; 3.5hp, triple head pump on a 100L tank; it puts out 12CFM @ 90psi; I can run my sandblaster flat out @80psi & it keeps up so, a die grinder, air sander, drill, even a rattle/impact gun, no problem...

Back when I was just getting into high school, my Dad bit the bullet and started buying the materials for a 36' X 40' pole barn. Cash on the barrel head. Which meant we got it enclosed and weather tight just before I graduated. Just being able to close the door on the weather was awesome , and we got by with the 1/2 HP single cylinder compressor that he received as a Christmas gift the year I was born.

I had to look for work in town (I'm still there); I tripped over a closeout Ingersoll T5 5 HP for sale, and Dad bit. It's a really great unit; to bad it's so big that we now only fire it up a couple of times a year.

The biggest job we've used it for over the last 10 years has been cleaning out the seed compartments in our planting equipment. And just for the of it, he and I went in together on a 2.5 HP, 110 V 21 gallon tank unit from HF for ~ $150.00 on sale. Does everything we've asked of the big one for daily chores, and gave a good accounting of itself for the over the top job.

So here's were I'm forced to ask; why does someone "Have To Have" something so big that they would need a zoning exemption just to run the occasional air tool?

 

[Poboy kartman]

Oh, to live in the perfect world....






It's probably a good thing you live in another juristinction; in some parts of the world, preaching to the choir can get you in trouble. Kind of like people proving that the emperor has no clothes....



Really? You have just noticed that most members of the forum will most likely never have access to 3 Phase power?



Back when I was just getting into high school, my Dad bit the bullet and started buying the materials for a 36' X 40' pole barn. Cash on the barrel head. Which meant we got it enclosed and weather tight just before I graduated. Just being able to close the door on the weather was awesome , and we got by with the 1/2 HP single cylinder compressor that he received as a Christmas gift the year I was born.

I had to look for work in town (I'm still there); I tripped over a closeout Ingersoll T5 5 HP for sale, and Dad bit. It's a really great unit; to bad it's so big that we now only fire it up a couple of times a year.

The biggest job we've used it for over the last 10 years has been cleaning out the seed compartments in our planting equipment. And just for the of it, he and I went in together on a 2.5 HP, 110 V 21 gallon tank unit from HF for ~ $150.00 on sale. Does everything we've asked of the big one for daily chores, and gave a good accounting of itself for the over the top job.

So here's were I'm forced to ask; why does someone "Have To Have" something so big that they would need a zoning exemption just to run the occasional air tool?

LMAO- UH...HA! What I said from the get...

 

[fowler]

Ha

A while ago work started a bid on some old airman compressors
No reserve
Two weld and they'ed be scrapped

Running 40hp 3 cly deisel engines

No one really bid on them and one bloke got 6 for $100

U would think its a real deal

But what the **** is the average person going to do with these
I was going to get one for the farm but it's too big for that

They're super quite
But they weight 600kg and use 50lts of deisel a day

And it's not relay socially acceptable to have a quad bike sized rusty rumbling box on your front lawn

Might drop the local property value