The portable air compressors sold at big box hardware stores like Lowe’s and Home Depot are perfectly suited for the jobs they’re advertised for: namely throwing some nails into the wall or filling tires. But if you try to respray your car with that $50 Black Friday pancake air compressor, you’re going to have a bad day. The relatively small amount of air they hold is almost guaranteed to be contaminated with oil and moisture, making it unsuitable for painting or even just blowing the dust out of electronics.
But all is not lost. [Stephen Saville] has done an excellent job documenting his work to turn these low cost homeowner-grade air compressors into something suitable for spraying auto body panels. But even if you aren’t looking to put a sick pearlescent finish on the family minivan, these tips are worth checking out. From increasing the usable volume of air in the system to separating out contaminants, these modifications can unlock a whole new world of pneumatic projects.
The big one (literally and figuratively) is the swirl tube [Stephen] builds out of an old CO2 cylinder. The idea is that this will centrifugally clean the air, not unlike a cyclonic dust separator. As the air enters the top of the cylinder and spins around, contact with the cold metal will cause any moisture to condense out and collect down at the bottom. Oil and other particles in the air should also get spun out, leaving a central column of cleaner air. The collected water and contaminants at the bottom can be occasionally purged out by way of the cylinder’s original valve.
With a source of clean and dry air sorted, [Stephen] next wanted a way to get it around his shop. Using scrap metal pipes he puts together a system that not only gives him air where he needs it, but also increases the volume of compressed air he has available. By using large smooth metal pipes rather than something like flexible rubber hose, the plumbing puts very little resistance on air flow. The pipes therefore can be considered something of an extension of the compressor’s primary tank.
In the video after the break, [Stephen] shows off his new air system by laying down a very nice looking coat of paint on a car hood, but he also goes through the hold build process if you want to see the nuts and bolts of his system. He gives some great tips on welding and working with dissimilar metals which are worth the price of admission alone.
Outfitting the workshop with an integrated compressed air system sounds like the perfect second project to tackle once you’ve got the built-in dust collection system up and running.