[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Electrolytic Cleaning Experiment

Yesterday I removed the rust from a small Gibeon as an experiment
in electrolytic cleaning.

I took pictures, you can view them as I describe
the process.

My first impression is that this process is extremely effective at
removing rust. My second impression is that it can seriously
alter the surface of a meteorite.

Here is a 16x photo of one part to show the level of rust:

   <URL: http://www.arachnaut.org/images/meteor/electrolytic-cleaning/rust-16x-300x251.jpg >

Here is an 8x photo of a side of the Gibeon before I started:

  <URL: http://www.arachnaut.org/images/meteor/electrolytic-cleaning/side1-b4-400x330.jpg >

You can see the rust clearly as well as flow lines on the surface and
a small melt lip at the bottom.

Here is that same side after cleaning:

  <URL: http://www.arachnaut.org/images/meteor/electrolytic-cleaning/side1-after-400x358.jpg >

All the rust is removed, but so is a considerable layer of thickness.
An inner groove is revealed that wasn't there before, and the bottom
meted lip appears etched. Almost no features of the original
surface remain.

Another side before cleaning:

  <URL: http://www.arachnaut.org/images/meteor/electrolytic-cleaning/side2-b4-400x346.jpg >

and after

  <URL: http://www.arachnaut.org/images/meteor/electrolytic-cleaning/side2-after-400x362.jpg >

I took this picture 12 hours after cleaning, and already rust is starting to 
from again. That small amount of red wasn't there when I finished.

Here's a picture of the setup:

  <URL: http://www.arachnaut.org/images/meteor/electrolytic-cleaning/overview-of-setup.jpg >

I used a 10 amp auto battery charger, a teaspoon of sodium carbonate in a few
cups of water, a stainless steel bowl, a third hand widget to keep the negative
connection from touching the stainless steel bowl, and a stainless steel paper clip
to hold the meteorite in the solution.

I started at 5:00 PM yesterday with the charger at 6 volts. The setup drew about 2 amps
of current. I also tried the 12 volt setting and the current doubled along with a greater
amount of electrolytic reaction.

Here is the first photo when I started, you can clearly see the bubbling:

  <URL: http://www.arachnaut.org/images/meteor/electrolytic-cleaning/start.jpg >

The positive is connected to the stainless steel bowl, the negative to the paper
clip suspended above the solution.

At about 1/2 hour intervals I stopped the process and examined the meteorite.
Each time I touched the specimen, small black flakes, like dandruff, were seen
on my fingers, so I used an old toothbrush to clean it under running water.
Sometimes, rather large chunks the size of salt crystals crumbled off.
I re-filled the bowl with solution as the level sank. Then I reassembled
the setup and continued until I couldn't see any rust with the naked eye.

At about 10:00 in the evening after about 4.5 hours of running, I could
no longer see any rust, so I stopped.

Before it got too dark, I took a picture near the end of the process, when I had
the voltage set at 12V. Most of the time I had the setting at 6V, but it was
getting late and I wanted to finish. At this time the ambient temperature was 
72 F and the solution in the bowl was at 112 F, the bowl was quite warm to the touch.
You can see all the crud in the bowl.

   <URL: http://www.arachnaut.org/images/meteor/electrolytic-cleaning/finish.jpg >

This morning when I woke up, I took this picture of the settled waste solution:

   <URL: http://www.arachnaut.org/images/meteor/electrolytic-cleaning/crud.jpg >

The process definitely removes rust, but it also seems to remove metal that doesn't
appear to be very highly oxidized - perhaps by removing rust under the surface.
At any rate, a lot of the metal that looked good appears to have been removed.

I didn't think to weigh the specimen before I started to see how much was removed.

I don't think I want to try this again - if a meteorite is really rusted,
this might make it crumble into pieces. I think the rusty meteorite with its
surface features and flow lines looks better than the cleaned version.

--
Jim Hurley  Freelance graphics artist
Web page design; graphics; multimedia
  <URL: http://www.arachnaut.org/ >

----------
Archives located at:
http://www.meteoritecentral.com/list_best.html

For help, FAQ's and sub. info. visit:
http://www.meteoritecentral.com/mailing_list.html
----------