Dust in the shop, and I mean the really fine stuff, is insidious to the point of being nearly invisible.
I finally dragged out the stepladder to replace bad tubes in my shop lights, and boy was I in for a surprise. I knew the fixtures were dusty because I could see it from the shop floor, but I had no idea just how dusty. They were beyond cleaning in place – ever try to effectively vacuum a swinging light hanging from a 10’ ceiling? – so I took the extra step of bringing them down to the workbench for a thorough cleaning.
I honestly don’t remember the last time I cleaned these, but it’s been at least a year or two, and that would have been a few quick swipes with the vacuum extension. But bringing them down to benchtop level allowed me to give them the best cleaning, and examine the dust itself. Sure enough, it was that powder-fine stuff; really, it’s so fine you can’t even really call it dust anymore. This is the stuff the experts warn is the truly dangerous dust.
On the plus side, I’ve seriously updated my dust collection system in the past year. To begin with, I got a new collector with canisters instead of filter bags, and it’s rated for 1-micron dust particles. Second, all-new dust ducting runs to nearly every tool in the shop. And finally, I topped everything off with an ambient air cleaner that seems to do a great job on fine dust.
Since these lights were in place before all that, it’s no wonder they’ve got a coating of powder on them. However, I’m eager to check those fixtures in another year and see what kind of difference my more efficient dust collection system makes.