@Loony661 original post got me thinking of the 70s when I was keeping a fleet of Hyster and Clark forklifts running and it seemed as if I was down at the radiator shop every other month. I loved the simplicity then, a core and 2 tanks. I would watch the guys unsolder the tanks, dip the cores in the bath I assume was acid, clean them and patch them or replace the core and solder the tanks back on with miles of good old lead solder, then pressure test and spraypaint them black
I bet those poor bastards developed all kinds of health issues later in life from all the acid and lead fumes
A far cry from any modern radiator shop I assume, if there even is such a thing anymore