HELP! Compressed air gurus

[StihlEchoingHusky]

Hello I hope alls well. I am not super knowledgeable (no *s-word) with compressors. And I have a feeling I already know the answer. I just want to get anothers input. Say I were to build a gasoline engine powered compressor, since it's already continuously spinning the pump, the only difference being weither or not the unloader is open or closed.
Would tank size matter if I had a compressor that was supplying 4 times the recommended CFM of the largest tool? I understand that the stored air is there For the tool to draw apon. So your pump and motor aren't on all the time. But using an engine vs a motor it would be on the whole time. I'm not thinking tankless. I have a very small shop and my plan its to utilize my Ingersoll rand grate mate 20gallon as a compressor base/storage and have the engine on a platform built outside. My current set up takes up a bit too much room. 20gallon as a "wet tank" feeding through 2 3/4 lines into a 27 then into a 33 with water separators between each one.

 

[Al Smith]

If you need more storage you can use any number of portable tanks tied into the system using quick connects .
My set up in my shop is a 5 HP electric two stage which can run on pressure or continous. Dumping into one or two 60 gallon tanks with a third 90 gallon if need be.. On at 130 psi off at 165 .Using the air to run a 13.5 inch air over hydraulic auto hoist that will lift a pick up truck at 60 psi I can run that thing up and down for 5 or 6 times before the comprsssor turns on .The entire DIY set up is just


junk I managed to find for next to nothing .

 

[StihlEchoingHusky]

If you need more storage you can use any number of portable tanks tied into the system using quick connects .
My set up in my shop is a 5 HP electric two stage which can run on pressure or continous. Dumping into one or two 60 gallon tanks with a third 90 gallon if need be.. On at 130 psi off at 165 .Using the air to run a 13.5 inch air over hydraulic auto hoist that will lift a pick up truck at 60 psi I can run that thing up and down for 5 or 6 times before the comprsssor turns on .The entire DIY set up is just


junk I managed to find for next to nothing .

I do have 3 tanks already. I wish To downsize number of tanks because of lack of room. 1 tank is taking up space where my welder will go and another tank is in the space my 240v lathe will be.

 

[OnlyStihl]

Kaboom!

What you describe sounds more complicated then warranted. Unless you are working out in the field, get a new bigger compressor. 240V, 80 gallons, etc. Space is tight, I get it, but with a thoughtful run to the dump (or two) and some shelving, space will magically appear. My 2cents.

 

[jacob j.]

You can also build a small shelter on the exterior of your shop and hard-mount a compressed air system there. At one of the dealerships I worked at - We had an 80-gallon 240v set-up that had its' own closet on the exterior of the main shop. Hard lines were run into the shop and terminals were placed at each workstation.

 

[RCBS]

You'll need a 100%/continuous duty-cycle pump. Will still generate heat while unloaded, just not as much.

Can you do an external tank?

 

[Al Smith]

Dan Henry AKA "Dozer Dan" in Pa. had a big old slow running monster of a compresser he had to move outside because it was so old and loud would wake the dead .Must have came over on the Mayflower .10 HP single phase motor the start switch went bad and he could not find another .I told him of a few places but also told him how to use a timer to start it .As they say there is more than one way to skin the same cat .
As a matter of fact I have a 10 HP three phase with a Speedaire 4 cylinder two stage comprssor sitting on a 120 gallon tank .It's a works in progress but I'll need to build a larger rotary three phase convertor .My present 5 HP unit won't be able to get-er-done

 

[Bill G]

I have to ask.......what consumption are you looking for?

 

[jacob j.]

I have to ask.......what consumption are you looking for?

He's gonna be painting ships - light cruisers.

 

[Al Smith]

Well since you mentioned it you could probably paint a lakes iron boat
using a 1 HP comprssor but it would take a long time .
However that aside I set up a three HP single stage unit with two 30 gallon portable tanks and 100 feet of hose to run two air nailers on the roof of my rental house . It did just fine but it never stopped running and did not over heat even in August .

 

[OnlyStihl]

Well since you mentioned it you could probably paint a lakes iron boat
using a 1 HP comprssor but it would take a long time .
However that aside I set up a three HP single stage unit with two 30 gallon portable tanks and 100 feet of hose to run two air nailers on the roof of my rental house . It did just fine but it never stopped running and did not over heat even in August .

I have used my compressor with a lot of different tools over the many years (>30) and I can't recall ever having to wait for the compressor to recharge the pressure. Yeah, it runs while I'm working, sometimes, but is never a problem. Last year I oiled the logs on the home (constant steady use over a good length of time), and that would have been the time to experience any short comings of the compressor. Maybe if I was running a sandblasting booth or sharing the line with other users, I might have interrupts in the air supply. My 25 gallon tank is probably more than enough for most all DIY users. I know it works for me.

 

[Al Smith]

You can get real creative about DIY compressers .For example use a smog pump from an automobile with a check valve but no tank and a 1/2 HP motor .A smog pump can put out 80 to 100 PSI ,it's small and often from a junk yard about $10-$15 . Using a clip on air nozzle it doesn't take that long to air up a flat tire .Then again a micro battery unit is usually less than 50 bucks and actualy does very well .Certainly beats a bicycle hand pump .

 

[Basher]

 

[legdelimber]

Speaking of the little portable rigs? My Sis bought one of those little "halo" brand jump packs with the compressor built into it. I pumped up a flat tire on her Honda civic and topped up the other three (5~8lbs).
The unit still had enough charge to kick over the engine after doing all of the tires.
The spring clamp jaws (plastic with a spring inside)) for the jumper clips have popped apart on two units though.
I just grabbed a spring clip/clamp out of the bag-o-clamps (Big-Lots store item) and used it to hold the wire/clamp jaw onto the batt terminal and carried on.
I usually have a couple of those clamps tossed in the cars anyways. Handy for hanging an extra paper on the too short sun visor or keeping the seatbelt from slowly choking me.

 

[StihlEchoingHusky]

He's gonna be painting ships - light cruisers.

Nope massive warehouses of industrial blow up dolls...... I mean tires ya we will go with tires i remember seeing your name on the list for "tires".

For real though. Large die grinders and sanders.as of now but Here soon I'll have a relatives large pneumatic tire changer along with vehicle lift. I do intend to paint those dolls, I mean "vehicles" as well. Ill be utilizing a after cooler going into a 10 gallon "wet" tank then into a 30 gallon main tank. I just want to build the compressor part of it once and call it. At lease until the pump needs rebuild or the engine.

 

[r7000]

Say I were to build a gasoline engine powered compressor...if I had a compressor that was supplying 4 times the recommended CFM of the largest tool?

looking at it if there was no tank, how would you achieve consistent pressure on the output supply line? an unloader can't do that, the unloaders purpose is to relieve pressure between the pump and tank after the pump has shut off so the compressor can restart while not under previous pressure. I suppose one could be rigged to be a pressure regulation mechanism but I don't know how well that would work.

the compressor is positive displacement, so without some large enough buffer tank in relation to demand the output psi would skyrocket, more so the larger the compressor output is to the demand size, the air has to go somewhere otherwise psi climbs... rapidly... until something gets overloaded... but the compressor connecting rod, overheat melt the piston ring, kill the oil, and so on. Not to mention air delivery performance regarding pulsation and heat and moisture.

I don't think you can get around larger cfm compressor output = larger buffer tank otherwise performance suffers in terms of the compressor kicking on and off more often and rapidly changing psi on the output side. but you would have to factor in the cfm's and utilization pressures in relation to the cutoff output pressure... tool use at 90psi with an output tank max psi of 150 where the compressor would cycle however often running output [tank] psi between 100-150. And the cycle time is calculate-able... cfm {minute} and PV = PV where V = cubic feet. so u should do that math... or start posting those numbers here.

 

[Bill G]

I believe someone is suffering with a serious case of overthinking over-kill

 

[Stihl036]

You can also build a small shelter on the exterior of your shop and hard-mount a compressed air system there. At one of the dealerships I worked at - We had an 80-gallon 240v set-up that had its' own closet on the exterior of the main shop. Hard lines were run into the shop and terminals were placed at each workstation.

The small shelter out of the shop is a good idea. It may end up out of the shop anyway.

 

[Boomer2230]

When I was painting semi trailers we used an airless paint gun. Sat on 5 gal pail of paint.