Just use Metcal fixed induction soldering irons. I just saw a power supply for an MX-500 for $100 on eBay and there is the hobbyist level PS-900 on sale new for under $300 on Amazon right now (which works just as well but might not last 30 years like an MX-500). Thermaltronics was started by some Metcal engineers after their patents expired so they’re a cheaper source of tips but I haven’t looked at their power supplies recently.
Unlike wellers and other soldering irons they don’t use a PID loop. They exploit the curry effect of the alloys their tips are made of and pump 2.6 MHz RF into the handle which keeps the tip heated the entire time with zero delay, even when contacting huge copper pours. The downside is that you have to change the (expensive) tips to change the temperature, but the upside is that it’s capable of delivering much more heat. Since the iron is capable of heating so fast, temperature control doesn’t really matter because it can melt the solder long before damaging nearby chips.
If you’re not using a solder oven, that’s the best option. It’s expensive but it’ll make a night and day difference to your soldering work. I’ve got a Metcal that’s almost 25 years old that still runs like a champ, is compatible with tips sold by Metcal and Thermaltronics, heats better than any soldering iron I’ve used since, and is easily repairable if it breaks.
I don't want to start a holy war, but the JBC system with integrated cartridge tips is at least comparable to Metcal for high thermal mass joints and (IMO) superior for very fine SMD work. The JBC system has the advantage of allowing one-handed tip changes while the tip is still hot. It's also very affordable to get in the door, thanks to the proliferation of cheap Chinese stations that are fully compatible with JBC tips. I do agree that the traditional style of iron with a separate heater cartridge and tip is obsolete.
The MX-500s have a design misfeature where power is constantly on internally. The switch only controls the output driver to the handpiece. Put these on a switched circuit for part time hobbyist use.
Unlike wellers and other soldering irons they don’t use a PID loop. They exploit the curry effect of the alloys their tips are made of and pump 2.6 MHz RF into the handle which keeps the tip heated the entire time with zero delay, even when contacting huge copper pours. The downside is that you have to change the (expensive) tips to change the temperature, but the upside is that it’s capable of delivering much more heat. Since the iron is capable of heating so fast, temperature control doesn’t really matter because it can melt the solder long before damaging nearby chips.
If you’re not using a solder oven, that’s the best option. It’s expensive but it’ll make a night and day difference to your soldering work. I’ve got a Metcal that’s almost 25 years old that still runs like a champ, is compatible with tips sold by Metcal and Thermaltronics, heats better than any soldering iron I’ve used since, and is easily repairable if it breaks.