Hello, resilient friends, let's open discussion on reducing electricity usage in the household. We'll come back to this topic room by room, but for today, let's look at the home workshop. This essay describes what I've learned so far, hoping that you would contribute what you know about air tools and reducing electricity use in the garage/workshop. More below.

I make do for now in our single-car garage with 120v power supply. Poorly insulated, as is the case mostly, and only propane heat in winter. But I got plans! I have the usual hand tools and power tools - electric, corded and 18v battery. A few years ago, I read a book about how the Amish live without electricity. The Amish are in many respects a model for personal and local community resiliency in the era of rapid climate change. They use air tools in their workshops.
Speaking of men with beards, there is only one men-with-beards-band :=) From Texas, as you know:

This is the book that I had read, which gave me loads of inspiration:

It forms part of a series by Stephen Scott on different aspects of Amish life.
Please buy books used. Please don't search with gargle; rather try DuckDuckGo: https://duckduckgo.com/

In chapter 24, the authors describe how a woodworking shop is powered with other means and in chapter 25, they describe how a manufacturing shop is alternatively powered.
One of the means of powering is compressed air, as used extensively in the automotive industry. The Amish use air tools and they are great macgyvers of converting electric power tools to compressed air and line-shaft drives.

So let's think about powering a workshop on air, in combination with solar-electric power.
(We'll come back to solar power and heating for the workshop in another post.) After reading the Amish book, I began to collect air tools at sales, clearances, used from kijiji, and so on. And I also put out the word for Christmas and birthday presents. That turned out well :=) More on specific air tools at the bottom of this essay.
I also began to research air power to learn more. I have no background in auto repair, but my brother-in-law is a mechanical genius and I asked him lots of questions. And good old internet searches. Here is some of what I have learned so far.

The Advantages and Disadvantages of Air Tools
From: http://www.thewoodwhisperer.com/articles/pneumatic-power-sanders/
Advantages

• The motor in your compressor is going to be more energy efficient than a bunch of tiny, cheaply made electric motors found in all but the highest grade power tools.
• The pneumatics never break down, since there are no motors in them; and because the air coming out of a compressor is super cooled, the machines never overheat (the biggest cause of electric tool failure).
• Look on craigslist and you’ll find 50-75 year old pneumatic tools that work just as well as the day they were made.
• Plus, once the cost of the compressor is absorbed, pneumatics are about half the price as their electric counterparts.
• Finally, the pneumatics have a much lower carbon footprint since they require less manufacturing, less copper wiring, electric components, etc.
• Actually, all pneumatic tools have a motor, albeit an air powered one, but they do last a very long time.
• They are also easy to maintain requiring only a few drops of oil once in a while.

Disadvantages

Dust control
Typically in larger shops pneumatic tools are used with large down draft tables to handle the dust.
Constant oil lubrication
But what we have found is that along with large volumes of clean dry air, we also needed a constant supply of lubrication for the air tools or they would not stand up. (and these are all Snap-on tools)
We needed to have an oiler installed in the main line.
My concern though, is this very light oil film going to be coming out the tools exhaust port contaminating the work surface and possibly posing finishing problems later on?

That persuaded me to keep going. I would love to hear about your experience with air tools and their pros and cons.

Compressors
This is where I got all the compressor info: http://www.sawdustmaking.com/index.htm
The main expense was the compressors. I started out small, being by myself. I have a small 2-gallon compressor for little jobs like tire pressurizing and other quick work around the house and yard. For bigger work, I bought a 20-gallon hobby class compressor at a clearance sale. I was restricted by my 120V power supply - and my budget. Sigh. They are Chinese-made, but have worked well so far for my limited needs to date. One fine day when my ship comes in (not the one with the black sails :=) I would like to find a serious compressor for peanuts.

Here are their specs and notes.

King Canada 20 gallon

Single phase
Duty cycle 50% i.e. 5 minutes on, 5 minutes rest
5HP, but actually 2HP
120V
14.5A, and 45A start-up
CFM @ 40PSI is 7.4
CFM @ 90PSI is 5.7
Max pressure is 125PSI
Operating pressure is 115PSI
RPM per no-load is 3400
Extension cord: no 12
Operating notes
Check oil level before use: red dot
Open drain valve after each use: not under pressure
Maintenance: Change compressor oil at 250 hours or 6 months

Campbell Hausfeld 2 gallon

Oilless
Empty tank after use
Open drain valve after use
Extension cord 25-ft 14 gauge

Insulated box
Compressors make a friggin racket like you will not believe. So my next party trick at the next place will be to build a sound insulated weatherproof box. I have to swot up the ventilation and electrical requirements. And can I fire up the 20 gallon with its 45A start-up from solar batteries? Lots to learn still.

HP Rating

The horsepower rating used to be a way of determining what size of compressor you would need, unfortunately the marketing guys are now exaggerating the horse power ratings to sell more compressors.
Check out how much electrical power it takes it to run, a true 5 HP motor will draw about 24 amps on a 220 volt circuit, (single phase power), whereas most overrated hobby compressors will run on a normal 15 amp 110 volt circuit which is only capable of running about 2 real HP.

CFM rating

Air Tools require a certain volume of air to run them.
The volume of air that a compressor produces is rated in CFM (Cubic Feet per Minute).
CFM ratings tend to be exaggerated just like HP ratings, but you should get 3-4 CFM per each real HP at 90 PSI.
The higher the pressure of the air that's already been squeezed into the tank, the harder the pump has to work to squeeze more air into it. So the same pump becomes less efficient at higher pressures.
That's why a compressor might be rated at 7.6 CFM @ 40 PSI but will only crank out 5.6 CFM @100 PSI.
Get a compressor with at least an 11 CFM rating so you can scale up as needed.
Air tools have a CFM rating on the box or in the paper work and should not exceed your air compressor.

Bars

In other countries it may be referred to as a Bar, one Bar being the atmospheric pressure at sea level, which equals 14.5 PSI.
Most hobby compressors are set up to run at 8bar. However, on most compressors the parts (check your equipment first) are rated to happily run at 10bar.
So you can crank the pressure up which will give you an effective larger volume.
Run through a regulator and dropped to around 5 bar will power most tools effectively without having to shell out for a larger compressor.

Tank

Usually measured in US gallons, this is not as important as it might seem.
A compressor tank doesn't produce air; it only stores air.
It is much more important to have a big enough pump and motor, because if you are producing as much air as you want to use, you'll never run out of air no matter how small the tank is.
If you want to run a tool steady, such as a sander, it is important to be producing as much air as you need.
A smaller tank is more portable and gets up to pressure quicker, whereas a compressor with a large tank doesn't start and stop as often and cools the air a bit better.

Single or two stage

Single stage compressors have one or more cylinders, and each cylinder pumps air directly into the tank.
Two stage compressors have at least 2 cylinders, and the air is pumped from one cylinder into another and then into the tank.
The main reason for buying a two-stage compressor would be if you need high pressure, but not too many applications need high pressure.
Therefore, you probably don't need a two-stage compressor. For most applications you would be better off to get a good quality single-stage compressor than a low cost two-stage compressor.

Drive and Oil

There are some very good compressors in both belt drive and direct drive versions.
The problem is that most of the direct drive compressors you'll see were designed to keep the cost down, and of course that also means low quality.
Direct drive compressors are directly connected to the motor shaft and therefore turn the same speed as the motor.
Engineers have designed some compressors to spin twice as fast so they could get more air out of them, and keep the price low but the life expectancy is cut down to about 1/4 of the low RPM compressors and the noise is almost unbearable.
If you don't need portability or if you need higher air volume, your best value will be a belt drive, oil lubricated compressor.
You should avoid high speed aluminum pumps, they have very low life expectancy and were built for low price, just like some of the direct drive compressors.
Most belt drive compressors are splash lubricated which means they have dippers on the bottom of the connecting rods to splash oil around in the crankcase. As long as there is enough oil in the crankcase, splash lubricated pumps should last a long time. Some of the best compressors have positive pressure lubrication, like in an automotive engine they use an oil pump to force oil to the bearing journals. This system allows compressors to be built to run at 100% duty cycle.

Duty cycle

The duty cycle is expressed as a percentage and tells you the number of minutes the compressor is allowed to run out of a 10-minute period.
For example, a low quality hobby compressor usually has a 50 % duty cycle, which means it shouldn't run more than 5 minutes out of any 10-minute period.
If you exceed the duty cycle the pump will get too hot and won't last as long as it should.
Most industrial compressors have at least a 75% duty cycle and some are as high as 100%, which means you can run them continuously.

Moisture

When air is compressed it gets hot, and when it cools water condenses out of it. The harder your compressor works the hotter it will get and the more moisture problems you will have.
Sometimes the best way to solve moisture problems is to get a bigger compressor.
Humidity can also cause you to have inconsistent moisture problems. A common moisture trap provides a low spot for water to collect but it's designed to collect droplets of water not water vapor so if the air is hot it will carry moisture through and then the water vapour will condense in the hose.
The trick is to cool the air before it gets to the moisture trap because if it cools after the trap, more moisture will condense out.
In a body shop they will usually use refrigerated air dryers to cool the air and remove the moisture.
It is important to have the moisture trap mounted at the end of the line as far from the compressor and as close to the tool as possible.

Start-up surge

There is often a problem using an electric compressor powered by a generator.
Most electric tools have a "start-up surge" they need more current to start than they do to run.
Electric compressors use about three times as much power to start as they do to run.
A compressor that runs on 15 AMPS may need 45 AMPS (or more!) to start.
The reason compressors don't blow your house's circuit breakers is that the demand is for a very brief time (thousandths of a second). The power lines have all the power your compressor needs, so the compressor starts, and the "spike" is so short in duration that your circuit-breaker doesn't have time to react.
But your generator probably doesn't have that starting power available, so it will make a valiant effort, fail, and shut down - and your compressor won't start at all. Make very sure your generator is big enough* to handle that huge start-up surge or consider using a gas-powered compressor.

*G: I got a good deal on a used 11KW diesel genny that I just love :=)

Air Tool System Parts

Hoses

The two common diameters of hose for home users are 1/4" and 3/8”.
Get a 25-foot long 1/4" hose, select a type that is flexible, pay a bit more if you have to, it is so nice to use you will be glad of it in the long run.
Any additional hose can be bargain 3/8" just put it between the compressor and the good 1/4" hose.
Even with a small portable 110-volt compressor there are times when the available power is not within reach of the project site, add more hose rather than using a long extension cord.
For exceptional distances use your larger diameter hoses at the compressor and step it down toward the end with smaller diameter hoses.

Connectors

A leaking air hose is usually caused by using cheap crappy quick connectors, spend a little bit more and get good ones.
Take a look at the male ends, are they molded in two parts or do they appear to be turned in a lathe, the molded ones will leak most times.
Add a connector directly to the compressor so it will be convenient to add more hose and keep your good hose at the tool end.

Air Consumption Guide

Air Hammer 4.0 CFM 90 PSI
Caulking Gun 4.0 CFM 90 PSI
Die Grinder 1/4" 4.0 CFM 90 PSI
Drill 3/8" 4.0 CFM 90 PSI
Drill 1/2" 4.0 CFM 90 PSI
High Speed Grinder 8.0 CFM 90 PSI
Impact Driver 1/2" 4.0 CFM 90 PSI
Impact Driver 3/4" 7.5 CFM 90 PSI
Impact Driver 1" 12.0 CFM 90 PSI
Jitterbug Sander 6.0 CFM 90 PSI
Nailer, Brad 2.0 CFM 30 PSI
Nailer, Framing 4.0 CFM 50 PSI
Ratchet 1/4" 3.0 CFM 90 PSI
Ratchet 3/8" 4.0 CFM 90 PSI
Spray Gun, Basic .5 - 3.5 CFM 20 - 45 PSI
Spray Gun, Commercial 4.0 - 7.0 CFM 30 - 70 PSI
Straight Line Sander 7.0 CFM 90 PSI
Upholstery Stapler 2.0 CFM 30 PSI

Rest schedule

It’s also good practice to stop using the tools for 5 mins after every 15 mins of use.

My Air Tools
Here's what I have so far.
Photo 1:

Left to right, then top:

• 5" Air Angle Grinder
• 3" Air Cut Off Tool
• 3/8" Reversible Air Drill
• Air Hammer
• 2" 2-in-1 Air Nailer/Stapler

Photo 2:

• Full-size Air Die Grinder
• 0.6L Spray Paint kit
• Vacuuming Air Sander

Photo 3:

• 1/2" Air Impact Wrench
• Air Hammer nr2
• 3/8 Air Ratchet Wrench
• 1/4 Air Die Grinder

Photo 4:

• Roofing Nailer

So that's as far as I've got in the quest for air power :=)

The next step for me is to figure out how to macgyver my own air distribution system: from compressor to a few work stations. I'll go look on Youtube and Instructables and see from there. At the moment, I have the compressor beside my workbench and things work fine. But things gonna change!

Then, comes the big one - setting up a workshop with air on the other side, after we have moved to our rural acreage next year (deo volente.)

I would love to hear from you about your experience and knowledge about air tools. And any and all questions are welcome. I don't know a whole helluva lot, but someone will.

Peace be with us, if we work to reduce our electricity consumption,
gerrit