How To Pick An Air Compressor For Your Woodworking Shop
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I started out my woodworking career with a quarter-sheet electric sander, quickly transitioned into a random orbit electrical disk sander and finally realized that I could substantially shorten sanding time with an air palm sander. I settled on a 5" Dynabrade sander and Sears 3HP air compressor. It would run out of air pressure almost immediately and the air sander would slow down to the point of being useless.
To make matters worse, I had three people hired as sanders and so I would need to keep three machines running at top speed all day long. I did some math and discovered that I would need a ten horsepower air compressor with a large tank to do this. I was lucky to find a used one for not too much money but it required three phase power and lots of it. The big air compressor was so loud it could be heard all over the building and down the block but it powered those three sanders from dawn to dusk. The good news is that it paid for itself in saved sanding time very quickly.
Air sanders are aggressive and efficient. They are light in weight when compared to their lesser electric cousins. My sanders took to them immediately and production took off. I was as happy as they were. Soon there was another machine besides the air compressor required having large amounts of air in the shop: an Onsrud inverted pin router. It was also great to be able to blow sawdust of benches and machine while cleaning upon the shop at the end of the day. The compressor was also used to spray finishes on the completed furniture.
Years later, I built a smaller woodworking shop in my home which only required one air sander running at a time. For that shop, I purchased an air compressor half the size and isolated in a soundproof room in one corner of the shop. I ran 3/4" galvanized pipe under the store floor to three regulators at three different convenient places. The machine I purchased for that shop as an 5 HP Ingersoll Rand model with an 80 gallon tank. In the 80 PSI demanded by my Dynabrade sander, the compressor would create enough atmosphere all day . I have to say that this compressor has been well built. All I needed to do was keep an eye on the oil level in the sight glass. At night, I would turn off the master air valve on the face of the device, leaving the power on, to silence the compressor for the evening.
I must assume that, having read this far, you have some interest in using a air compressor to power air tools in your store. Most probably, a 2-stage reciprocating air compressor will fulfill the requirements of a small to medium shop. As a rule of thumb, a 5 HP air compressor will power a single air compressor, a 7.5 HP machine will power two and a 10 HP system will be needed for 3 sanders.
The size of the compressor's air tank is a significant consideration: The bigger the tank, the more frequently the compressor will need to cycle off and on, This is hard on both the motor and compressor pump over time and it uses more electricity. I would not even consider an air compressor used to power an air sander with less than a 60 gallon tank and I would feel much more comfortable with an 80 gallon tank.
The type of electric power required by an air compressor is another consideration. If you've got three-phase electricity available at your location, fine. Three phase motors have a tendency to use electricity a bit more efficiently than single-phase motors. Large air compressors will all require 3-phase power but the 5 HP versions come either way. If you don't have 3-phase power available, you can manufacture it using a rotary or electronic phase converter as I did in my smaller store. Whether you utilize single or three phase power, you'll require 230V AC power for single-phase motors and 208 or 220V AC for the three-phase selection. Be sure to check the voltage and amperage needs of almost any air compressor before you buy it. Electricians can be costly.
A two-stage compressor pump is a must to get a system of this size. Two-stage machines have 2 cylinders, one bigger than another. Air is introduced to the massive cylinder where it is partially compacted and sent to the more compact cylinder for final compression into the tank. As air is compressed, heat is created and so a good machine will have a finned intercooler built in.
Compression not only generates heat but squeezes water out of the atmosphere which winds up in the tank. Tanks can rust internally over time and when this isn't kept in check, the rancid atmosphere tank can finally burst causing tremendous damage and even death. That's why it's critically important to drain the tank of water every single day. Most machines come equipped with a drain valve at the lowest point of this tank. If you don't wish to spray water over the ground under the compressor, then you may want to consider piping it in the valve to another place such as beneath the ground or to a drain. Piped water will flow uphill into a sink because it is being pushed out of this tank by compressed air
I started out my woodworking career with a quarter-sheet electric sander, quickly transitioned into a random orbit electrical disk sander and finally realized that I could substantially shorten sanding time with an air palm sander. I settled on a 5" Dynabrade sander and Sears 3HP air compressor. It would run out of air pressure almost immediately and the air sander would slow down to the point of being useless.
To make matters worse, I had three people hired as sanders and so I would need to keep three machines running at top speed all day long. I did some math and discovered that I would need a ten horsepower air compressor with a large tank to do this. I was lucky to find a used one for not too much money but it required three phase power and lots of it. The big air compressor was so loud it could be heard all over the building and down the block but it powered those three sanders from dawn to dusk. The good news is that it paid for itself in saved sanding time very quickly.
Air sanders are aggressive and efficient. They are light in weight when compared to their lesser electric cousins. My sanders took to them immediately and production took off. I was as happy as they were. Soon there was another machine besides the air compressor required having large amounts of air in the shop: an Onsrud inverted pin router. It was also great to be able to blow sawdust of benches and machine while cleaning upon the shop at the end of the day. The compressor was also used to spray finishes on the completed furniture.
Years later, I built a smaller woodworking shop in my home which only required one air sander running at a time. For that shop, I purchased an air compressor half the size and isolated in a soundproof room in one corner of the shop. I ran 3/4" galvanized pipe under the store floor to three regulators at three different convenient places. The machine I purchased for that shop as an 5 HP Ingersoll Rand model with an 80 gallon tank. In the 80 PSI demanded by my Dynabrade sander, the compressor would create enough atmosphere all day . I have to say that this compressor has been well built. All I needed to do was keep an eye on the oil level in the sight glass. At night, I would turn off the master air valve on the face of the device, leaving the power on, to silence the compressor for the evening.
I must assume that, having read this far, you have some interest in using a air compressor to power air tools in your store. Most probably, a 2-stage reciprocating air compressor will fulfill the requirements of a small to medium shop. As a rule of thumb, a 5 HP air compressor will power a single air compressor, a 7.5 HP machine will power two and a 10 HP system will be needed for 3 sanders.
The size of the compressor's air tank is a significant consideration: The bigger the tank, the more frequently the compressor will need to cycle off and on, This is hard on both the motor and compressor pump over time and it uses more electricity. I would not even consider an air compressor used to power an air sander with less than a 60 gallon tank and I would feel much more comfortable with an 80 gallon tank.
The type of electric power required by an air compressor is another consideration. If you've got three-phase electricity available at your location, fine. Three phase motors have a tendency to use electricity a bit more efficiently than single-phase motors. Large air compressors will all require 3-phase power but the 5 HP versions come either way. If you don't have 3-phase power available, you can manufacture it using a rotary or electronic phase converter as I did in my smaller store. Whether you utilize single or three phase power, you'll require 230V AC power for single-phase motors and 208 or 220V AC for the three-phase selection. Be sure to check the voltage and amperage needs of almost any air compressor before you buy it. Electricians can be costly.
A two-stage compressor pump is a must to get a system of this size. Two-stage machines have 2 cylinders, one bigger than another. Air is introduced to the massive cylinder where it is partially compacted and sent to the more compact cylinder for final compression into the tank. As air is compressed, heat is created and so a good machine will have a finned intercooler built in.
Compression not only generates heat but squeezes water out of the atmosphere which winds up in the tank. Tanks can rust internally over time and when this isn't kept in check, the rancid atmosphere tank can finally burst causing tremendous damage and even death. That's why it's critically important to drain the tank of water every single day. Most machines come equipped with a drain valve at the lowest point of this tank. If you don't wish to spray water over the ground under the compressor, then you may want to consider piping it in the valve to another place such as beneath the ground or to a drain. Piped water will flow uphill into a sink because it is being pushed out of this tank by compressed air
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