Half a croissant, on a plate, with a sign in front of it saying '50c'
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The Anti-Tarnish Nub

Apply Cathodic Protection to Sterling Silver Utensils
  [vote for,

Sterling silver tends to tarnish after meals, particularly those containing a surfeit of sulfur, for it is untimely oxidized. Black grimey Ag2S, or silver sulfide (sorry, can't do the subscripts,) results. After a big meal with many houseguests, one could spend fifteen minutes of simply removing tarnish. This painstaking process could be eliminated, however.

Here's where Cathodic protection comes in. Cathodic protection, a simple process based on simple electrochemical principles, is used in many industrial applications, particularly those involving boat hulls and corrosive seawater. Simply put, attaching a hunk of metal that readily oxidizes to the metal that you wish to keep intact will cause the hunk of metal to oxidize in place of whatever it is that you don't want to tarnish.

Notches are to be cut on the hilt of the handles of a certain set of sterling silver utensils, making an "outlet" at the very base of the handle. Next, a metal that is more prone to oxidation, such as Zinc or Aluminum (ideally a metal with many valence electrons), is cut into a small nub with a protrusion, encased in a non-reactive metal for aesthetic purposes, and is fastened into the groove at the base of the handle. When the silver reacts with the sulfur in the food, electrons flow out of the nub, through the silver, and thus the silver is saved from tarnish. When the metal is completely oxidized, simply throw out the nub and fix a new one in its place.

Perhaps some sort of indicator could be used to check the remaining amount of non-oxidized metal in the nub. I haven't quite worked out that detail yet.

WordUp, Jun 25 2004


       So you're going to zinc plate your silver plate (after a fashion)? That should save you almost 13 minutes after dinner...
phoenix, Jun 25 2004

       Sacrificial anodes on silverware?
normzone, Jun 25 2004

       phoenix, I think you missunderstand. He isnt coating it, he is using another metal to prevent the damage. Of course the nub would need to be in circuit. But I like. Of course nothing beats Sold Gold cutlery ;)
not-arf, Jun 25 2004

       Take your tarnished silver and throw it all in a metal tray filled with salty water. Toss in a lump of zinc. Shake gently. Works better than the best silver polishes around. Still stinks to high heaven as the sulphur dioxide bubbles off, but it works.
Freefall, Jun 25 2004

       Interesting, [Freefall]. Is it important to the reaction that the tray be metal? What type of metal? Stainless?
bristolz, Jun 25 2004

       In order for the sacrificial metal to work, there must be a current path between the metals that flows through the liquid and another current path that does not flow through the liquid. If you put a zinc blob inside the handles of silverware, it would protect against tarnishing when the handles were immersed along with everything else, but would not provide protection when only the tip was wet.
supercat, Jun 26 2004


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