On 13/09/2019 13:15, AJH wrote:
I need to solder a patch onto a rusty diesel tank, previously I used
60/40 tin lead solder but this is not readily available locally will a
lead free plumber's solder still wet fluxed steel?

AJH

brazing is more likely to last.

flux and brass wire or silver solder if you don't have a powerful enough
torch to heat it.