What's the thinking about using an impact air wrench to undo tight nuts?
Thinking about crank nuts and clutch / gearbox nuts without having to put a bar through the con rod little ends.
I do it. Don't see a problem.
dont have a problem with an air gun in certain circumstances.
be aware of fine threads, dont F1 (car racing)the nut in the socket when putting back on , you risk cross threading.
I start on the lowest setting and work up, dont forget some threads left hand. My gun has the push button forward/reverse and I use that to try to jerk it loose.
todays modern equivalent is the Milwaukee impact gun which is battery operated but expensive, (Other makes available).
as for the crank and rods, need to hold it tight enough to use the gun. I often use for the engine sprockets. normally the gun comes out after a breaker bar is tried first, more control but the gun can be used by a single person if no help available.
Have used a Milwaukee 3/8 drive impact gun with good success. Mine has 4 torque settings and the torque can be varied using an app on my mobile.
Lovelly tool, but was not cheap. Justified as I need it for work
I have an impact driver, in fact I have 2, a 10V & an 18v, But I would hesitate to employ them to tighten anything screwing into aluminium! I also have one driven by compressed air and the only thing I would tighten with that would be things like wheel nuts etc.