What tools do you use for BGA soldering? I’ve seen people (well, dosdude1) using board preheaters and hot air stations, but I could never justify the expense for the amount of board rework I actually do.

I have Chinese hot air station and I am super happy with it. Airflow is nice, temperature constant. Simple manual control. The device has writing 998D on it. This device also has soldering iron attached, but it is very bad, does not have enough power for usual soldering tasks.

Hot plate, flux pen, hot air gun.

Important caveat: The downside to this is you can't inspect it (without an x-ray machine), and if you screw up, you're going to need a new chip (Re-balling does not look approachable/time-efficient)

Thank makes sense, thank you! Is there a rule of thumb for how high you set the hot plate? I’d be worried about SMD components on the side in contact with the hotplate.

You're right that that is a concern. I think I set mine for 190C? Don't remember. But as you infer, my goal is to get it slightly below melting temperature so the the other components' solder doesn't melt. (Disaster if they do, then the board gets jostled or you knock a component with tweezers). Then when you hit it with the air, just that component melts.

Also, it seems to not melt if you don't flux the pads prior. Not really sure why.

Reballing isn't too difficult. It's mostly about buying all the special tools and supplies. You need a specific template for each BGA pad layout and jars of the right size solder balls.

Some people also just put solder paste on the PCB with a stencil and reflow that into solder bumps that you then solder the chip to. I find that method suspect but if it works it works