> He underscored that air loss due to the crack are insignificant. "This leak is like as if you’d drill the hull with a 0.2 mm diameter drill. I’m not sure such drills even exist in household.
I had to check my collection of PCB drill bits when I was reading it, and yes, I confirm that I'm a proud owner of a 0.2 mm drill at home, it was the smallest one in the box ;-)
The existence of a drill is no guarantee that you can actually create a hole. I once was a battle tank maintenance guy and we had to replace a cover placed in front of the armor. The replacement had holes in different positions, no problem, just drill a new hole, right? An hour and a few broken drills later we gave up. No doubt there are drills that work on that armor-steel, my point is, depending on the material just any drill may not be good enough. An hour of hard work barely caused a <0.5mm "deep" scratch to appear!
PS: We solved the problem by not solving it. Attaching three points instead of four was enough, de decided. That tank would never see a real battle but was only used for training anyway.
True. But if it's a PCB drill as (s)he said, then it's likely either solid carbide or has a carbide tip. Hold everything rigidly enough and run that drill at the right speed and feed rate, and there's a good chance that it will drill armor plate.
I had to check my collection of PCB drill bits when I was reading it, and yes, I confirm that I'm a proud owner of a 0.2 mm drill at home, it was the smallest one in the box ;-)