I hope you used an old penny, newer ones are only copper plated
A mapp torch will burn a lot hotter than a propane torch will, be careful not to get it to hot, good luck.
they still workI hope you used an old penny, newer ones are only copper plated
99% of plumbers use a flux called nokarode. its not a acid, nor corrosive. plumber for 15 yrs herePlumbers solder flux is corrosive. i hoped you cleaned it up really well afterward.
You should use a good rosin non-corrosive solder flux instead.