[NewCandle] Quick update on my silver displacement experiments

[Keith Nagel]

Hi All,

Just a quick update on my on-going experiments with the silver/aluminum
system. I fabricated some electrodes; aluminum rods ground into lozenge
shapes, with a hole in the center to allow for support inside a test
tube. They were mechanically polished with aluminum oxide sandpaper
to a bright finish. The tubes contain .2M silver nitrate solution. This shot
shows three
tubes, all the same except for the size of the electrodes, after 8 days.

http://www.kpnconsulting.com/newcandle/download/k_silver1.jpg

The surface area of the electrode determines the reaction rate so
you can see roughly what the surfaces looked like at different points
in the 8 day timeframe. The black anode area coating eventually begins to
break off
along with gas being generated. Why this material tends to get stuck to
the silver is a puzzle to me, outside of the obvious fact that
it is getting stuck on the way to floating to the surface.
Yet it seems to "crawl" around to other parts of the electrode?
What is this stuff? I assume the gas in H2, but I haven't tested it
yet. Clearly the available silver has either been depleted or
enough aluminum is in solution to start a competing reaction
to the silver displacement.

K.