A Blast Cabinet and a point


Below is a ‘new to me’ very large blast cabinet I picked up a month ago. It was sitting, unused for many years, in another hangar on our airport. It came from a friend, a thank you for sharing the fundamentals of personal defense with his daughter, for whom he had purchased a S&W Airweight.  A shop tool someone had paid $3k for in the 1970s or 80s, swapped for a rewarding afternoon at my backyard range, showing a petite woman in her 50’s how the word ‘No’ is a command, not a pleading request, when you have the right tool in your hand.



Above, the cabinet and the separator are products of Zero Mfg. Once the finest brand of abrasive blasting, great products made in Missouri, today a relic, a victim of a very clever bankruptcy engineered by bean counters who thought nothing of the manufacturing jobs they threw away.  It is 40″ x 36″ x 30″, the whole front opens, the round discs are counterweights on the door.


Over many years at the airport, this cabinet had several owners, but none of them found it to work very well, and it eventually fell into disuse. This made little sense to me, as this was an industrial tool, it should have worked better. All the hoses and wiring were rotted from sitting, and I carefully replaced all of it. When going through the air lines to the foot pedal, I found the culprit. Some time, many years ago, someone had put an adaptor fitting in the air line with a restrictive internal diameter, about 1/8″. I replaced all the air lines with 1/2″, and made sure the smallest restriction in the line was 3/8″.  The nozzle in the BNP gun is 3/16″, the smallest orifice, as it should be. Set up this way the cabinet is now doing an incredible rate of work. Its performance was a tiny fraction of this for decades, all due to a single fitting that’s carelessly installed by someone now long gone.


The aviation Point:

Over the years, I have seen a dozen Corvairs where the owner was plagued by some issue, poor performance, overheating, rough running. Most of these people went to the internet to ask for feedback, and were provided with an endless array of highly improbable reasons, and equally arcane ‘solutions’. Just like the restrictive fitting in the air line, the answer was always simple; just ask what is different from other installations that are nearly identical, but have long proven to work, there lies the answer. It is almost always something ‘custom’ the builder included, often at the suggestion of a local expert or a mystery person on the net.  When I show this to people, something as simple as never having opened the nose bowl inlets on their plane, they express some disbelief, later a little thanks, but I’m yet to see one go back on the internet and tell everyone the solution was something simple, and just making it as I suggested in the first place.




About William Wynne
I have been continuously building, testing and flying Corvair engines since 1989. Information, parts and components that we developed and tested are now flying on several hundred Corvair powered aircraft. I earned a Bachelor of Science in Professional Aeronautics and an A&P license from Embry-Riddle Aeronautical University, and have a proven 20 year track record of effectively teaching homebuilders how to create and fly their own Corvair powered planes. Much of this is chronicled at www.FlyCorvair.com and in more than 50 magazine articles.

5 Responses to A Blast Cabinet and a point

  1. Kevin Purtee says:

    You got all the credit I could give you for improved cooling when you made me change the mailbox front of the cowl on Rosie to the swoopy cowl. And that’s not the first time I’ve publicly announced on the internet that you were irritatingly right.

  2. Kevin Purtee says:

    Of course, I didn’t start the troubleshooting process by asking advice from people I’d never met and who had never built a Corvair flight motor….

  3. Lane Seidel says:

    Something simple. Hmmm. Sounds like another case of Occam’s Razor. Can’t tell you how many times it has worked for me.

  4. mquinn says:

    ww check out TP tools. (https://www.tptools.com/) – they have great guns for the booth if yours is needing umph. I have 2 cabinets and have replaced the OEM with this one and made a WORLD of difference. Clean, dry air, and fresh media make a difference too!!!

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