Edge discharge characteristics are well known in the electro plating industry. Even 40 pound rectangular electrodes eventually assume a v shape with rounded edges. Corners have 5 edges and 2 points. Points erode faster than edges. A coin only has edges. A wire only has a point and will gradually sharpen itself out of existence like a pencil. Bending the wire ends away from each other like an inverted V with a slightly more pronounced bend away at the lower portion helps distribute the erosion. Ken
At 06:22 PM 5/31/02 -0700, you wrote: >> Russ Rosser wrote: >> >> replied that flat bar eventually assumes a "V" shape due to an "edge >> effect." Therefore, A QUESTION TO ALL YOU WHO USE SILVER COINS: DOES >> THE ANODE REMAIN ROUND OVER ITS LIFESPAN on their way to becoming a >> piece of silver foil? > >Hi Russ, > >My silver coin started out about four years ago at 1.53" in diameter by >.125" thick. It is presently 1.36" in diameter by .08" thick in the >center and .05" around the edges, and still quite round. The leading and >trailing edges in the water current of the stirrer are the same >thickness, and the coin appears to be eroding(?) pretty equally all the >way around. > >This coin had a big eagle head on the front which was about flush with >the raised rim around the edge. The edge (and eagle head) was about .02" >above the flat surface of the coin. A very soft image of the eagle head >is still discernible and this accounts for the difference between middle >and edges. The back of the coin had some light artwork nowhere near as >substantial as the eagle head, and the back is essentially flat. > >I suspect the raised and knurled edge might raise the surface area >substantially when the coin is new, so there would be an initial rapid >fall-off in surface area as the edge became smooth, and ideal current or >time set for a ridged coin would be different than for a smooth one. >Anyone? > >I use 30 VDC with a stirrer motor in a quart jar, silver round for the >anode and .130"x4" stainless rod for the cathode. Run until the current >rises to 1mA which takes several hours. Much higher than 1mA and silver >starts rapidly precipitating on the cathode. Wipe the cathode but not >the anode. No special reason for the size/shape cathode; it just >happened to be what I had and I never replaced it when I replaced the >silver wire with the silver coin. > >Ron KC7ZWA > > >-- >The silver-list is a moderated forum for discussion of colloidal silver. > >Instructions for unsubscribing may be found at: http://silverlist.org > >To post, address your message to: [email protected] > >Silver-list archive: http://escribe.com/health/thesilverlist/index.html > >List maintainer: Mike Devour <[email protected]> > >
