How Much Air Compressor?

[Lucid Moments]

So I am in the (very slow) process of having a shop built. My main purpose for the shop is in support of my Road Racing addiction. Most of the work I do is mechanical. Swap a motor, replace bent or busted parts. Very little if any body work, but I may do more when the shop gets built.

The point of all that is that I find I use relatively few pneumatic tools. Electrical tools have gotten so good that there is not much that can't be done with them. At least so far. I am pretty new at all of this though so the chances that I am totally wrong is a real possibility.

My current plan is to just go with a small ~2hp portable compressor. 10 or 15 gallon tank. Am I overlooking or underestimating a need? Should I go with a 5hp 60 gallon tank?

 

[drsung]

From my limited understanding of air compressors, the rule of thumb is "too much is never enough".

That being said, I have a portable twin tube compressor now that is great for airing up tires and running a nail gun. Other than that, it's pretty useless. I am in the market for a 60 gallon as soon as I build the shop.

 

[Radix2]

Sand blaster,plasma cutter.

Outside of those any compressor will handle the remaining airing up and misc.

you should know by now if air tools are your thing or if you want cordless.

 

[Leaflessshadetree]

Tools where I feel limited with a mid-sized (5-10 CFM) compressor. Using a cut-off tool or grinder (electric works but air is often better and smaller/mor ergonomic tool). Sandblasting is another big demand if you are doing large parts.

 

[gmtech]

Personally I think its hard to beat the 60 gallon Kobalt from Lowes for $500. Its a great compressor for a one man hobby shop. But Im sure here shortly there will be a lot of comments that you need to buy a million dollar compressor to air up bicycle tires.

 

[sberry]

How much an investment is all this? Does getting a real machine become a deal breaker? The standard is 5 hp 2 stage for running body tools. This will run grinding and sanding and limited sandblast. This can be a 1 shot deal. A 3hp used to be popular for mechanics tools and airing hi pressure tires but when costs changed and 100A service became standard it went to 5.
The advantage of a decent unit is,,, there is headroom for tools. This is just coming on and supplying regulated air at recommended tool pressure when a single is turning off, stores 2x the energy and has quick recovery and short run for many tasks.

 

[sberry]

The 500$ comp is good too, it has its place. The op already found a small unit limiting. The slightly better one is better, it will run plasma and it doesnt take great pressure to blast but it is limited to run tools.
I have seen very few people that do significant work regret buying a good comp.
A cheap 2 stage run short run tools well, not sure what the lifespan is.

 

[NUTTSGT]

Using a blast cabinet and even a die grinder will start eating up air. If you have a small compressor and have decent sized project, you are going to get tired of waiting on the compressor to catch up.

I'd recommend a vertical 60 gallon compressor. But a decent one and never look back.

 

[LS6 Tommy]

If you race, you're going to want a small portable compressor to take to the track and something more substantial for the shop.

Tommy

 

[StingRay]

Sandblasters, needle scalers, air grinders, air sanders, plasma cutters, etc can eat up air fast. My 60 gal upright can do quite a bit at 12 cfm at 90 psi but the sandblaster will eat that up right away. I run a second gas powered unit as well when I blast. It just keeps up with 24 cfm total. One of those tiny things doesn't belong in a car guys shop.

 

[Citation]

If you are on a budget and buying new a 3hp 60 gallon looks good. If you are including used and ok with around $500 I would take a look for a lower end (or high end if you find it) 80 gallon 5hp. This also assumes you have the needed power/wiring. From what I've seen of used compressor prices, a 60 gallon compressor that was ~$500 new is asking $300 to $400 used. 5hp, 80 gallon compressors of various types seem to go for only a bit more.

OP, an alternative path, look for a deal on a 120v used compressor. See if it does the job. If yes, your dinner. If no, sell it for what you paid for it and get a bigger compressor.

 

[Kaizen]

i got a 5hp 60 gallon husky unit when i started restoring a car. had about 11.5 cfm. 500 dollar machine. added another 250 bucks on piping and filters and regulator. while it powered everything including a pressure blaster. It did it for short increments. even a 3 inch cut off wheel would exhaust the tank in under ten minutes and it would not keep up with it. Thats in my old garage.
Started building new garage and needed a small compressor for air nailer. got a husky unit for 250 bucks. has oil in it. little ten gallon upright i think. it has handled all of my auto impact needs as well as nailers no problem.
those are imo stage 1 and 2. I'll be getting a stage 3 upright with 18 -20something cfm in the future. The body work really is the killer. those tools go through a lot of air

 

[WIKDRacing]

I just took delivery of a Bel Aire 60 gallon 5 HP 2 stage compressor for my “hobby” auto shop. I haven’t had a chance to wire it up or plumb it yet but I got a great deal on it while at SEMA so it was a no brainer for me.

 

[metaleltr]

Currently overworking a 34 year old 60 gallon 5hp compressor doing light body work and sandblasting. When it dies an 80 gallon 7.5hp will replace it. For mechanical work a 60 gallon would be enough to meet most people's needs. For even hobbiest level body work I feel an 80 gallon is the way to go.

I've seen one man Mechanical shops get by on a 30 gallon compressor but I wouldn't want to.

 

[Citation]

Just an FYI as we talk about pump hp. Remember that for a while the per numbers were getting heavily inflated. A "5hp" compressor from 1999 might only be a 3hp using current ratings. Motor current and flow rate are probably better comparisons.

 

[Lucid Moments]

The issue for me isn't so much the money. I don't mind spending the money if it will be useful, but I really dislike wasting the money if it won't be useful. Also the noise, I have been told that compressors have made some fair advances in noise, but I have been in shops where you couldn't think when the compressor kicks on.

 

[WhiskeyRanger]

I bought the 26 gallon Quiet Tech Kobalt and love it. Quiet (obviously) and enough to run anything I need it for. No body stuff and I use mostly cordless tools like impacts, drills, angle grinders, etc. If i needed more, it would be an IR 60 gallon 2-stage 240V 5hp because I know its quiet too. No more loud compressors for me.

 

[Augus7us]

I got a deal on a 5HP 80gal and I own maybe one air tool. Why wish you had more down the road. I also knew I would buy a blast cabinet and other air hogging stuff in the near future.

This really comes down to you. You don't have a blasting cabinet or die grinder or plasma cutter. Will you? Is it even a thought? If so and it were me I'd but a big compressor 5HP/60G. If you know you'll never mess with any of that and stick with battery tools then buy the small one and don't look back.

If I were into race cars, I'd already be looking at 5hp - 60/80g compressors.

 

[raferguson]

I use die grinders a lot. My right angle die grinder is one of my most used tools in my shop. Not knowing any better, I started with a high end 110V compressor. I spent more time waiting for the compressor than grinding. Then I bought a 60 gallon 230V compressor, roughly 10 SCFM. This was a huge improvement, but I still had to stop sometimes to let the compressor catch up. Of course, sometimes you set down the tool anyway, and the compressor can gain a little on the grinder. I now have an 80 gallon 230V compressor, draws 23 amps, puts out about 15 SCFM. I love it, it pretty much always keeps up; but if I get grinding continuously, it runs continuously, so I don't have any excess capacity.

My view is to forget the 110V compressors, go directly to a 60 gallon 230V compressor, and only go up from there if needed. As others have said, sandblasters require a lot of air, and die grinders use a surprising amount of air. 60 gallon compressors are pretty easy to find on craigslist, and are not that expensive.

 

[Lucid Moments]

I don't see myself ever having a sandblaster, but a die grinder, or cut off tool is a possibility, and a plasma cutter is something I really want.

 

[Citation]

Lucid,
Since you are in the Atlanta area (roughly) I took a look at Craigslist. Just a few thoughts on things I found...

Here is an example of a powerful, older compressor for not much money
https://atlanta.craigslist.org/eat/tls/d/150-psi-air-compressor/6717309646.html
7hp Speedair (Grainger).
Here are a few other "big" compressor. By big I mean typically 80+ gallon tank, 18+ amp motor, likely two stage etc.
https://atlanta.craigslist.org/atl/pts/d/air-compressor/6746862114.html
https://atlanta.craigslist.org/wat/tls/d/shop-air-compressor/6699443409.html

https://atlanta.craigslist.org/nat/tls/d/2stage-80-gallon-air/6713155205.html
This seems to be the same as the one I lucked into for my dad. It's falls into that ~$1000-1500 retail price range. It's only 4hp (something like 18-19A). It doesn't have a magnetic starter and if it is the same on my dad's got, it has front panel air connectors and a regulator.

For more money someone wants to sell you a 60 gallon "6.5hp" in newer, better condition for $775
https://atlanta.craigslist.org/nat/tls/d/devilbiss-air-compressor-60/6737074108.html
The speedair is likely a true 7hp while this one would be called 3hp today (230V, 15A).

Here are a few similar offerings.
https://atlanta.craigslist.org/sat/for/d/air-compressor-220volt-60/6741845278.html
https://atlanta.craigslist.org/sat/tls/d/air-compressor/6730172756.html
https://atlanta.craigslist.org/atl/bar/d/60-gallon-kobalt-air/6721692346.html

The $300 one may be worth a look since that's enough off the ~$500 that a new, similar compressor goes for. As far as I can tell this sort of compressor is typically 60 gallon, 15A, 230V, 10-12 CFM @90 claimed, single stage pump.

But if you want to start off smaller, well something like these 120V models will do a lot of things and aren't pricey.
This one for $80 is very similar to the CH belt drive compressor I have. It's about as good as any 120V compressor will get. If it all works $80 is a deal.
https://atlanta.craigslist.org/eat/tls/d/air-compressor/6730790447.html
This may also be reasonably serviceable and again at this price you could use it until something better comes along and not be out much
https://atlanta.craigslist.org/sat/tls/d/husky-air-compressor/6745033466.html

 

[Lucid Moments]

I hadn't even thought about buying a used one. I don't know why not. I am not ready to buy yet, the shop floor hasn't even been poured so I have no place to put it, but I will definitely remember this when I am ready.

 

[bowhuntr311]

I went back and forth on this when I built a few years ago. I had prior in my last house/garage; 120v single stage craftsman 15 gallon vertical. Loud as heck and constantly running. I vowed I'd have a big compressor and never look back. Then the time came to pony up the $$$$. I really had a hard time with it and kept thinking the 15gallon would be all I'd need for a tire here or there and electric would solve my problems. The compressor died on me and I went to the parts store and the 5hp 60gallon was on sale....I bought it and havent looked back. I dont think I will ever look back and wish I would have bought a smaller compressor.

 

[cspcrx]

Is there a such thing as a 60gal 110v? Seems like when you get to that size tank they jump to 220v.

 

[bowhuntr311]

Is there a such thing as a 60gal 110v? Seems like when you get to that size tank they jump to 220v.

I havent seen any newly manufactured 110/120v in a 60gallon tank. An old family friend had a 120v homemade contraption (110v 1hp motor with single stage pump Im guessing) on a huge tank (possibly an old LP tank)....I remember it banging away up on a shelf for a long time while he used air tools.

 

[sberry]

Is there a such thing as a 60gal 110v? Seems like when you get to that size tank they jump to 220v.

120v is such a limited circuit. You can make 2x by some changes to pump and motor and on a big tank it works so much better by allowing the pump to run longer and more volume delivery for more time. 3x in better cases with better machine.

 

[sberry]

Is there a such thing as a 60gal 110v? Seems like when you get to that size tank they jump to 220v.

The little ones are portable, designed for general circuits. Any decent work place that can afford space usually can get 240 and a dedicated circuit which is better than a general. Think electric dryer, could get one to run on 120V and 15A service but would take a lot longer, instead you provide bigger service for the appliance.

 

[sberry]

I don't see myself ever having a sandblaster, but a die grinder, or cut off tool is a possibility, and a plasma cutter is something I really want.

You need about 3 real hp to make that stuff function basically. If its on single stage some waiting on sanding but will run a plasma continuous.

 

[joe_padavano]

I finally got my 23 SCFM, 7.5HP compressor up and running early this year. I'm now kicking myself that I waited so long and wasted so much time waiting for that smaller compressor to catch up.

Unless you MUST have a brand new compressor, buy a used industrial three phase compressor. They are usually cheap since no one wants three phase. I bought a brand new Baldor 7.5 HP single phase motor on line for about $600 and swapped that in. I haven't looked back.

 

[f150skidoo]

I finally got my 23 SCFM, 7.5HP compressor up and running early this year. I'm now kicking myself that I waited so long and wasted so much time waiting for that smaller compressor to catch up.

Unless you MUST have a brand new compressor, buy a used industrial three phase compressor. They are usually cheap since no one wants three phase. I bought a brand new Baldor 7.5 HP single phase motor on line for about $600 and swapped that in. I haven't looked back.

I agree with buying a used industrial compressor. I recently bought a 80 gallon industrial compressor but it was built with a 5hp single phase Baldor motor and a canadian made 3 cylinder pump. A good industrial compressor will run at half the rpm as a cheaper home owner grade compressor so their not that loud when running. I can have a conversation with someone in normal talking volume standing beside my compressor while its running.

 

[Lucid Moments]

I finally got my 23 SCFM, 7.5HP compressor up and running early this year. I'm now kicking myself that I waited so long and wasted so much time waiting for that smaller compressor to catch up.

Unless you MUST have a brand new compressor, buy a used industrial three phase compressor. They are usually cheap since no one wants three phase. I bought a brand new Baldor 7.5 HP single phase motor on line for about $600 and swapped that in. I haven't looked back.

I am definitely going to look hard at used equipment when the time comes to shell out the money, but I can't get 3 phase where I am going to be.

 

[bamawildcat]

I am definitely going to look hard at used equipment when the time comes to shell out the money, but I can't get 3 phase where I am going to be.

You can swap the motor and pressure switch to single phase. It has to be a good enough deal to be worth that.

 

[sberry]

Take some time then and find a deal on something basically plug / wire/ and play, something ready made for single phase.
If we would have had net back in the day I would have shopped some used but,,, I can do the build. If I want to use it I look for teady made and dont fukk around at every chance.