Several years ago, and I can't recall how it happened, I came into an inexpensive and easy way to clean rust and grease, and, in some cases, paint, from your rusty cast iron and sheet metal parts. Taking advantage of common household cleaning products, items many of us have laying around the garage, kitchen or laundry room, and some science, you can clean parts from a single bolt up to an entire trailer frame through a process known as "electrolysis".
What you need:
The science behind rust removal by electrolysis.
Using a plastic, or non-conductive bucket (not metal), mix a solution of 5 gallons water to 1/3 to 1/2 cup laundry soda. Mix well so all soda is dissolved. Do not try to use other salts. You won't get better results and dangerous effects may occur. Caustic soda, for example, is far too corrosive. Solutions of ordinary table salt can generate chlorine gas (toxic) at the positive electrode (anode).
Clean the electrodes so
they aren't too rusty - especially at the top ends - they need to make good
electrical contact with your wire or cable AND with the water. I take mine to a
wire wheel and give them just a real quick going over. Place electrodes in
bucket around sides, so the clean, rust free ends stick up above the bucket. Use
clamps or some means to hold them in place around the perimeter of the inside of
the bucket or container so that they cannot move freely or fall into center of
bucket. The electrodes must not touch the part(s) to be cleaned, which will be
suspended in center of bucket. I use small C clamps. Whatever you use, it
shouldn't be copper, and will get a bit messy if it gets into your cleaning
Suspend part to be cleaned into bucket so it hangs in the middle, not touching bottom, and not touching electrodes. I place a piece of rebar across top of bucket (see photo below) and bolt a small piece of chain to my part to be cleaned, and clamp the chain on the rod so that the chain hangs from the rod, and suspends the part into solution below. The part to clean then becomes the "cathode".
Attach battery charger - place NEGATIVE LEAD (this is critical!!) on the piece that is to be cleaned. Attach POSITIVE, or RED lead of charger, to electrode "grid" formed when you placed electrodes, or rods, into bucket and tied them all together.
Make sure electrodes and part to be cleaned are not touching each other, then turn on charger. Within seconds, you should see a lot of tiny bubbles rising from the part suspended in the mixture. Do not do this inside, or in a closed area - those bubbles are the component parts of water - H2O - hydrogen and oxygen. Remember the Hindenburg?
See how the rust and bubbles are attracted to the electrodes in the photo below? You will need to clean them from time to time - they will get covered with gunk; in fact, after many uses, they will have eroded down and need to be replaced. That is why I use rebar - it's easy to get, cheap, and most of all - SAFE FOR YOU and your environment! You can pour the waste solution on the lawn and it won't hurt it. Do watch out for ornamental shrubs, which may not like iron rich soil, however. No use making your spouse mad!
How large an item can you clean? Well, it's up to your imagination, your budget - because it takes water, your time and wife's patience. Terry Lingle demonstrated this process on a very large scale using a tank made of plywood and lined with plastic, a DC welder for power supply and hundreds of gallons of water. You will need to use more electrodes with larger parts and a larger "tank". The resulting photos can be seen here - along with an explanation of his setup.
How small? A student
recently used the description on my web site as the basis for her science
project in school. She used a computer power supply for the power source to
clean a small part in a plastic bucket on a table. (photos coming soon)
- Make sure
no spills can get to the battery charger. (electrocution potential as with any
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