Monday, November 18, 2013

Air Compressor Upgrade FTW!

8:03 PM Comments 0

Over the past year or so, we have been slowly improving and upgrading all kinds of items in our shop…shop carts, assembly tables, work stations, and machinery. The most recent addition to our shop is an new air compressor. Previously, we used two 5hp Ingersoll Rand piston air compressors, one for the shop and one for the paint room. They have served us well over the past 25 years, but as we have grown, we are demanding more CFM than a single 5hp air compressor can deliver.

The need for more air volume was also driven by our desire to upgrade to pneumatic sanders in the sanding room. We are constantly burning through the consumer model electric sanders, no matter the brand. They just aren’t made to run for 8 hours a day, 5 days a week. Either the on/off switch or the internal brushes fail, or the random orbit action just breaks down. These sanders are also bulky and heavy, causing all kinds of hand fatigue for the user.

It was at this time that I discovered many of the manufacturers of pneumatic sanders also make electric versions. These high-end electric sanders are designed to mimic the pneumatic sander in their size, weight, and action. They have all the advantages of their pneumatic cousins, but run off a 110V outlet, rather than an air hose. This option was quite attractive, since it offered a simpler solution to our problem. We could buy two electric sanders now and focus on finding a newer 5hp air compressor later. But, after doing more research and analyzing all our options, we decided that a 15HP compressor and the pneumatic sander route was the way we needed to go.

At this point I began really diving into the wild world of compressors and, in a nutshell, here is what I learned. Piston compressors are less expensive than similarly sized rotary screw models, and are less expensive to maintain, but are not made to run continuously. A 65% duty-cycle is optimal, while rotary screw models prefer 100% duty-cycles.

I began my search in the used machinery market and quickly narrowed the field down to two candidates, a rotary screw 15 HP Gardner Denver and a 15 HP piston-style Champion. The Gardner Denver only had 10,000 hours on it, which meant it had another 20,000 or so left in it before it would begin reaching the end of its usable life, had been regularly maintained throughout its life, and came with a 120 gallon storage tank. The Champion was a 2006 model, which was 3 years newer than the Gardner Denver, looked brand new, came with a 100 CFM Great Lakes air dryer, and was about $1,000 cheaper.

Champion Air Compressor

In the end, we chose the Champion over the Gardner Denver for all of the reasons listed above, and because of two other factors mentioned earlier; duty cycles and maintenance costs. Our shop never requires a steady amount of air from the compressor. One day we may only be using one pneumatic sander and the random air hose, while the next day we may be running two sanders, an edgebander, an up-cut saw, and an air router running simultaneously. This kind of fluctuating demand would be detrimental to the rotarty-screw compressor, shortening its overall life because of the constant on-off cycling required. A piston compressor, on the other hand, can more easily deal with these wild swings in production demand. Rotary-screw models also need their maintenance done on-time, or catastrophic damage can occur. Piston compressors also need regular maintenance, but tend to be a bit more forgiving if they are ignored for a little while.

After using the air compressor for about a month now, I can unequivocally say that the shop is better off by having a larger air compressor. With the increased CFM, we can run two pneumatic sanders and a pneumatic router with no hesitation in any of the tools. We also use to have random air pressure drops, which would shut down the edgebander mid cycle. Thankfully, that is a thing of the past.

My advice to any shop looking to upgrade an air compressor is to do your homework, educate yourself on the different types of compressors, learning all pros and cons. Know what your shop will require and use that knowledge to decide which machine will be the best fit. There is no “one-size-fits-all” solution.