Update: I stopped finishing broom handles by hand after 12 years, and a kid on my crew in Tulsa changed my mind
I used to hand rub every broom handle with a wood float because that was how my first foreman taught me back in 2011, and I figured machines always leave swirl marks. Then last month a 22 year old on my crew in Tulsa ran a magnesium float on a 40 by 60 slab and the finish came out cleaner than mine with zero chatter. I tried it on a driveway pour two weeks later and cut my time down by almost half. Anybody else make the switch late, or do you still keep the hand float for edges only?
You said "zero chatter" and that is the part I want to hear more about. Was the mag float brand new or broken in? I ask because I ran a mag years back on a garage slab and got tiny ripples where the blade edge caught, but mine was fresh out of the box. Did the kid do anything different on the passes, like angle the float or float it wetter than you would with a wood float? And when you tried it on the driveway, did you still hand float the edges after, or did the mag handle those too?