Removing Tarnish From My Nan's 86 Year Old Silver Christening Cup

well my grandmother was given this cup by her uncle in 1927 when she was christened.   it was generally ignored and abused sicne then, and it had turned completely black.  we were talking, and looking over some old photos when she mentioned that she would love to have the cup be restored to its original luster.  or at least not look like horrible black. 

so, I had to research a way to remove the tarnish without polishing the hell out of it and destroying the delicate engraving.

I came up with using an electrochemical process using hot water, baking soda, salt and tinfoil.

this strips the sulfur from the silver, leaving the silver as it was before it tarnished.

It takes multiple applications to get  the cup back to it's original colouring but it is amazing at how well this works, while still being gentle on the silver.