Automobile radiators are cheap and available (talking prohibition and depression era, here) and readily adapted for use as ethanol distillation boilers, and it’s my understanding that this is a true “hillbilly liquor makes you go blind” trope.
If you are a diligent engineer, you wash the radiator really well before cooking. But I have to wonder how possible it is to clean a radiator under low-budget field conditions. And I assume some cooks don’t clean their boilers because they don’t know or don’t care.
UPDATE (and tip of the hat):
@Purplecat observes:
Washing them out would get rid of the traces of anti-freeze, but the main problem with using radiators in a moonshine still was the lead solder which would gradually leach into the product. Also, the product would inevitably be a bit sulphurous, if you’re using less copper in the set-up.
