In most industrial buildings
it takes very little time at all to cover every girder and rafter with the dust of the manufacturing process.
I have been in the habit, for many years, of hitting things as hard as i can, with my bare knuckles. I do this because I spend a lot of time on my hands and knees under machinery, and the callouses on my knuckles have helped protect my hands. This has an added benefit: if you have to hit someone, their jawbone feels like a pillow after thirty years of hitting steel and brick and concrete.
A year or so back, I was leaving the factory of one of my customers, thumping the building columns as i went, and then I came to column L14.
Years of remodeling and layout changes in the plant has left L14 floating, just standing there supporting nothing. it is still connected to a network of lateral supports, but the roof has been resupported by a different structure, at that one location.
So I thump L-14, and instead of giving me a hard “bang” that makes no sound but I can feel it through the bones of my hand, it goes “Thrummmmmmmm!” and an area about twenty feet wide by about 12 feet long gets showered in dust.
Yesterday, a tour of people came through the shop looking at some new processes; these people were predominantly competitors, and I recognized them all as people who have caused me some trouble in the past.
I waited until they got in just the right spot, and then I whacked L14 a hell of a whack.
Sometimes I’m a real stinker.

I spent just long enough as an electrician at Stewart-Warner to know exactly the kind of dust and cruft to which you refer…and yes, you are indeed a stinker :)
You SURE you ain’t related to me somehow?
Don’t ya just love it when a plan comes together???
You, my good fellow, are a freeking genius!
Don’t you love it when you can really ding someone in a sly, crafty, intelligent way? Any fool can punch or yell, and any fool usually does, but there’s nothing like pulling off a “muahaha” moment. “Oops, sorry guys, I just slipped and tried to catch myself *evil grin*.”
Long as you got it on their machine and not yours. If you just got it on them, kool!