My familiarity with manufacturing hardwood furniture has taught me that about half the time involved in constructing each chair, table or cabinet is taken up with sanding. When you are trying to make a livelihood in the woodworking industry with hourly employees you must cut inefficiency to a bare minimum. This does not mean becoming a tyrant but, instead, removing any and all impediments that may be slowing construction, sanding and finishing.
I started my woodworking career with a quarter-sheet electric sander, quickly graduated to an orbital electric disc sander and finally realized that I could substantially cut sanding time with an air palm sander. I settled on a 5” Dynabrade sander and Sears 3HP air compressor. It took me less than an hour to realize my faux pas: The small compressor I bought could not begin to keep up with the air requirements of the air sander. It would run out of air pressure almost immediately and the air sander would slow down to the point of being worthless. I would then have to wait for several minutes for the pressure to build up again to get another minute of sanding.
Compounding the problem was the fact that I had three people hired as sanders and so I would need to keep three air sanders running at 10,000 RPM all day long. I did some arithmetic and discovered that I would need a ten horsepower air compressor with a large tank to keep up with the demand. I was lucky enough to find a used one with a reasonable price tag but it required three phase power and lots of it. I had to consider the additional expense of an electrician to wire it up to the building’s 208 volt 3-phase power. The enormous air compressor was so loud it could be heard all over the building and down the block but it powered those three sanders continuously. The good news is that it paid for itself in production efficiency very quickly.
Air sanders are aggressive and effective. They are lightweight when compared to their lesser electric cousins. My sanders took to them immediately and production took off. I was as ecstatic as they were. Soon there was another machine besides the air compressor that required having large amounts of air available in the shop: An Onsrud inverted pin router. It was also great to be able to blow sawdust from benches and machines while cleaning 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 it in a soundproof room in one section of the shop. I ran ¾” galvanized pipe under the shop floor to three regulators at three different connection locations. The machine I purchased for that shop as a 5 HP Ingersoll Rand model with an 80 gallon tank. At the 80 PSI required by my Dynabrade sander, the compressor would produce enough air from morning to night. I must say that that compressor was very well built. All I had 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 side of the air compressor, leaving the electricity on, to silence the compressor until the next work day.
I must assume that, having read this far, you have some interest in utilizing an air compressor to power air tools in your wood shop. Most likely, a 2-stage reciprocating air compressor will fill the needs of a small to medium shop. As a rule of thumb, a 5 HP air compressor will power one sander, a 7.5 HP machine will power two and a 10 HP machine will be needed for three sanders. industrial air purifier