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Electrolysis for rust removal

mickyd

I wanted to create this thread to deal with the topic of electrolysis. It's showing up in various threads and seems to have enough interest where we can devote a specific thread for it.

This thread is a continuation of the topic from the Navel Jelly thread https://forum.shopsmith.com/viewtopic.php?t=3301. It morphed into electrolysis.

From that thread, read posts #4 through somewhere around #28 and then pick it up again here. If there's not posts below, come back later.

We left off with a dialog about why it's recommended to use washing soda vs. baking soda.

mickyd

Good info

electrolysis.pdf

. Doesn't say exactly why washing soda is better that baking soda as the previous thread left off but thought it was worth posting.

beeg

From the PDF, here's the reason for using washing soda.

Electrolyte solution is made from water with a soluble salt

(usually sodium carbinate or washing soda) added to the

water to enhance the conductance of electricity. Household

lye can be used, however eye protection and gloves should

be worn when handling the solution.

Add one tablespoon of soda to a gallon of water. If you

have trouble locating the washing soda, others have

reported success with baking soda.

NOTE: It is the current that cleans, not the solution; nothing

is gained by making a more concentrated solution

heathicus

mickyd wroteCharger, craiglist, $10

Baking soda, supermarket, $1

Scrap sheet metal, craiglist, free

Plasitc bucket, home center, $5

Water, your faucet, $.0001

Results - Priceless

Unfortunately, there is no local Craig's List site. And even those that are somewhat close have very little on them. That's one of the few things I miss about living in the Northern Virginia area. Anything I wanted was on Craig's List at just about any time I looked for it and wasn't too far away.

I guess there are always garage sales, but my wife and I both enjoy sleeping in as late as the kids will let us on weekend mornings too much to get up and do the garage sale thing.

foxtrapper

I do use the elecrolysis method at times, but not always. Cleanlyness and surface area are *CRUCIAL* to making it work. Bigger is exponentially better.

The first time I tried it I used a piece of rebar. The results were quite disapointing. Then I tried it with an old hand saw blade. MUCH faster. My main tank has two sanded bare large flouresent lamp reflectors in it. You can watch the rust leaping off the pieces I place in this tank.

For fun, stick your hand in the tank. You can really feel the current, especially as you get close to either the anode or cathode.

After a few hours of use I'll reverse the current to clean the rust off my plates. Rust buildup essentially shuts down the process.

I've also used the chileaten method (beet juice) and acid baths.

A vinegar soak is my preferred method for smaller pieces, and I keep several gallons of vinegar around just for that purpose. It also works very well on awkward and recessed areas.

Chleaten works, but is slow and stinks to high heaven. I don't consider it worthwhile, except for dunking a complete engine or such.

mickyd

Here's an article that touches on why washing soda is preferred over baking soda of the electrolyte solution. It's PH related.

http://www.holzwerken.de/museum/links/electrolysis_explanation.phtmlr

Shows a massively rusted part cleaned up

http://www.davidbradley.net/ERR.html

Note: This guys talks about using high amperage. NOT NEEDED. All it does is heat the water. It doesn't amount to a hill of beans for doing a good / fast rust removal job.

A fellow woodworking guy

http://www.rickswoodshopcreations.com/Miscellaneous/Rust_Removal.htm

DON'T USE stainless steel for the anode like this guy talks about. It results in nasty hexevalent chromium getting into the solution which is NOT environmentally a good thing. Stick with regular magnetic carbon steel sheet metal.

iclark

mickyd wroteStick with regular magnetic carbon steel sheet metal.

just don't assume that

magnet-sticks-to-it = other-than-stainless-steel

martensitic stainless steels such as 410 and the 600-series will hold a magnet just fine. some shops keep those alloys around because they are easier to machine than the 300 series.

if someone here knows how to tell the difference between clean, not-rusty carbon steel and martensitic stainless, I'd appreciate hearing about it.

preferably methods that don't require x-rays or electron microscopy:rolleyes:

Ivan

JPG

iclark wrotejust don't assume that

magnet-sticks-to-it = other-than-stainless-steel

martensitic stainless steels such as 410 and the 600-series will hold a magnet just fine. some shops keep those alloys around because they are easier to machine than the 300 series.

if someone here knows how to tell the difference between clean, not-rusty carbon steel and martensitic stainless, I'd appreciate hearing about it.

preferably methods that don't require x-rays or electron microscopy:rolleyes:

Ivan

Set out in the great outdoors for a couple of weeks while wetting it down daily.:D

mickyd

Good webpage on the chemistry of electrolysis. http://www.holzwerken.de/museum/links/electrolysis_explanation.phtml

Should the website ever go away, here's the pdf version of it below.

electrolysis_explanation.pdf

Anomalocaris

I know it has been a long time since anyone posted to this page, but will the cheapo rebar at Lowes work as a plain carbon steel anode?

reible

I use rebar in my tank. I got mine at Menards but it is all the same stuff I believe.

I also use old chicken wire to clean the tank/rebar so it will last a very long time.

Ed

JPG

Any steel/iron will work. Stainless steel - NO! Works, but you lose the green chemistry award.

ERLover

I guessing here if it has an anti corrosion coating on it it is useless. Rebarr.

ljhhontx

I have used old brake rotors with good success, you can lay them in the bottom of the tank and turn them over when they get crusty on one side.

oldiron

I have tried several metals as well and I like using plain "All-THREAD". Plain rebar will work however, It is a much slower process. As others have stated, Higher amperage is not needed. And don't think using a much more concentrated mix of washing soda will do a better job.

As for cleaning smaller parts, It's hard to beat a vinegar soak. Just make sure the part you are soaking is "Completely" submerged in the vinegar otherwise you will have unwanted heavy rusting of any part which was not submerged.

If you want to use vinegar but need the part derusted quicker, Apple cider vinegar is by far better and faster........ I use apple cider vinegar for removing "Mill scale" from carbon steel prior to welding. I simply plan out my welding project so the steel has a few days to soak. The vinegar does a wonderful job and it is far safer than other acids... The vinegar soak should be done in a closed plastic container(5 gal. bucket with plastic lid, etc..).

I keep several gals. of Apple cider vinegar along with several gals. of white vinegar on hand at all times.

Mike