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Letter 139
Why does this electrolysis
derusting trick work?
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I have been removing rust from metal tools by using a galvanized
bucket of water and suspending the tool in the water by a string. I
connect a twelve volt
battery charger [link is to product info at Amazon] to the tool
and the other side to the bucket. Overnight the rust turns to black
goop which I wash off and further buff out the tool. Works great. I
got it from a tip in a wood magazine. Can someone explain why this
works. What is the "electrolysis?" process here ? Thank You.
Dennis Slabaugh
Hobbyist Woodworker
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the rust on your tools is FeO, of iron oxide, when you run the
electricity through the tools the electrons reduce the FeO into Fe
and O2, oxygen gas. Every time and equal part of the galvanized
bucket which is Zinc is oxidized into ZnO or Zinc Oxide a white
powder. So every time you do this, a little of your bucket is blown
away, watch for holes! haha
Adam Hoalcraft
college student - usa
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+++++++
Getting rid of rust can cost a fortune in chemicals but
if you have the time and can fully submerge the item to be
de-rusted, here is a cheap way to do it. Submerge it in a
black molasses and water solution. 1 part black molasses to
9 parts water. I have 40 litres of the stuff mixed up.
Where I used to work on Norfolk Island (in the South
Pacific, halfway between Australia and Fiji - the place
where the majority of the descendants of the mutineers from
the Mutiny on the Bounty live), we had a 200 litre (44
Imperial gallons, 55 US gallons) drum mixed so we could dip
big stuff. Like any small island, because of salt spray,
rust is a real problem over there.
Really severe rusting will need a week or so in the
solution. I recommend removing the job after a few days and
wire brushing to remove the loosened scale, a quick hose
down and return to the pot for another go. It is essential
that the steel is fully covered. Unprotected steel will
corrode very badly at the air/solution interface where it
come out of the solution. Note: Some alloys e.g., zinc will
be severely corroded by this stuff so keep it for iron and
steel only or test it first.
I bought 5 litres of blackstrap molasses (stuff they feed
horses) from my local feed and produce store. It is quite
cheap.
Ron Beckett
- Emu Plains, NSW, Australia
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