Professional Results From Cheap Air Compressors

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 whole 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.

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Kill the Exhaust, Not Your Lungs with the Fume Coffin

As if slinging around 40 watts of potentially tattoo-removing or retina-singeing laser beams wasn’t anxiety-inducing enough, now comes a new, scary acronym – LCAGs, or “laser-generated airborne contaminants.” With something that scary floating around your shop, it might be a good idea to build a souped-up laser cutter exhaust fan to save your lungs.

We jest, but taking care of yourself is the responsible way to have a long and fruitful hacking career, and while [patternmusic]’s “Fume Coffin” might seem like overkill, can you go too far to protect your lungs? Plywood and acrylic, the most common materials that come across a laser cutter’s bed, both release quite a witch’s brew of toxins when vaporized by a laser beam. The Fume Coffin clears the air in your shop by venting it to the outdoors after giving it a good scrubbing through an activated charcoal pre-filter and a HEPA polishing element. Both filters are commercially available so replacements won’t be an issue, and the entire thing is housed in a wooden box that gives the device its name.

Since it’s ejecting 200 cubic feet per minute, you’ll have to provide at least that much make-up air, but other than that the Fume Coffin should be a welcome addition to the shop. We’ve seen a few other attempts to handle LCAGs effectively before, including a DIY charcoal and automotive air filter design.

Breathe Easy with a Laser Cutter Air Filter

A laser cutter is a great tool to have in the shop, but like other CNC machines it can make a lousy neighbor. Vaporizing your stock means you end up breathing stuff you might rather not. If you’re going to be around these fumes all day, you’ll want good fume extraction, and you might just consider a DIY fume and particulate filter to polish the exhausted air.

15203365_644939182347358_619032134291602214_nWhile there’s no build log per se, [ZbLab]’s Facebook page has a gallery of photos that show the design and build in enough detail to get the gist. The main element of the filter is 25 kg of activated charcoal to trap the volatile organic compounds in the laser exhaust. The charcoal is packed into an IKEA garbage can around a prefilter made from a canister-style automotive air cleaner – [ZbLab] uses a Filtron filter that crosses to the more commonly available Fram CA3281. Another air cleaner element (Fram CA3333) makes sure no loose charcoal dust is expelled from the filter. The frame is built of birch ply and the plumbing is simple PVC. With a 125mm inlet it looks like this filter can really breathe, and it would easily scale up or down in size according to your needs.

No laser cutter in your shop to justify this filter, you say? Why not build one? Or, if you do any soldering, this downdraft fume extractor is a good way to clear the air.