Thread: Well, that went well, not!

hi Ken

you need to move the plates away from the lathe bed ..more distance = less current flowing . You might have to find a larger container , the container MUST be non-conductive eg plastic

BTW I use this method to remove rust and paint with caustic soda I have found that the laundry powder from the Warehouse works great as well .

I use a cheap K mart charger that must be 30 years old..you only need around 2-3 Amps .

Mike

If the water is fairly shallow to proccess the feet, and you tossed in a handfull of bicarb, the solution may be too strong, allowing excess current. My understanding is that the solution is generally fairly weak, with just enough concentration to allow limited current flow. There is nothing in the system to limit current flow other than electrolyte concentration, overdo the concentration and the solution is a short circuit.

Two suggestions;

1. Make a new solution with a similar amount of water and about a teaspoon of bicarb. Check the current flow and add very small amounts of bicarb til you get the current into the 2A range.

2. Use the existing solutuin and 12V source, but connect with 1 or 2 12V brake lights (parallelled) in series with the bath to limit current to the 2 A range.

Hi Ken,
When you say "In the bottom of the tub, I placed a sheet metal plate for the feet to sit on. Around the four walls I placed four more sheet metal plates, all electrically connected"
Does that mean you had the plate the feet were on connected to your sacrificial anode?
If so then I suspect that's the source of your problem.
Assuming the feet are rusty they will have high resistance to start with but this will drop rapidly as the electolsys progresses.
Put an insulator between the bottom plate and your feet or suspend them with string or wire above it and all should be ok.
When using electrolsys the larger the surface area of what is being cleaned and the anodes the higher the current will be, the strength of the electrolyte usually doesnt matter that much.

If I have misunderstood, my appologies and the best thing would be to reduce the size of your anodes or as Mike said increase the distance between them.
Sheet metal anodes probably wont last long, I use rail bed plates, the things that go betwen railway line and the sleeper, you can usually find some lying along the train lines. Watch out for the big rolling things though.
Some people use stainless for the anode but this results in cromium in your used electrolyte which is not a good thing.
Cheers,
Greg.

Off to the supermarket to buy some washing soda. In my first attempt at electrolysis, I used bi-carb soda (baking soda). Maybe that's why everything went pear shaped.

The Arlec battery charger is ok, must have tripped out on thermal overload. My 24v dc power supply blew a fuse, that was a quick fix.

I'll try electrolysis again tomorrow using the Arlec switched to low, and ditch the metal plate in the bottom of the tub. Instead I'll connect each foot with a cable directly, and do one at a time.

Negative lead to the work, and positive leads to the electrodes hooked up in series.

Wish me luck.

Ken

Whether it's baking, washing or bicarb soda you need a lot less than you think.

I start off with nothing except water and then slowly add small amounts of concentrated soda solution (mixing it in thoroughly) until the current is around 4 A.

Thanks BobL.

I'll give your method a go, the Arlec battery charger has a voltage & current meter on it, so should be a snap.

Watch for the smoke in my area.

Ken

HI,
Might be to many Electrode Plates as You said. I remember when I used the procedure I had only one Anode and that was a piece of 50mm x 8mm Stainless Flat bar about 350mm long (the anode stood upright in the Container). I have tried it with both Washing Soda and Bi-Carb Soda, I actually seemed to get better results with the Bi-Carb.

Ken
Have look at this thread started by BobL april 2011.

https://www.woodworkforums.com/f65/el...07/index3.html

Post 45 by Ropetangler suggests the use of stainless steel anodes produce "hexavalent chromium".
Remember the movie "Erin Brockovich"

I've used 2 strips of old lead sheet as anodes in a bucket & washing soda, works well. Try this site aswell =

Rust removal by electrolysis
This site warns about the use of SS aswell.

Regards
JohnQ

I'm now using only two ms electrodes, each about 100mm x 100mm, and am attempting to clean both lathe bed feet at the one time.

Initially the current draw was zero until I gradually added some dissolved washing soda (Lectric soda crystals). Steadily the current rose and is now sitting on roughly 3 amps.

Q1. Can I expect this process to remove the paint along with the rust?

Q2. How long will this process take, hours, days, weeks?

I'm getting all the froth and bubbles, so things are cooking.

Had to put a cloth over the tub to stop puss from drinking out of the tub. Didn't know cats like water, mine does.

I'll keep updating as things progress.

There's a couple of snaps just to keep AB from winging that I don't do anything on my Hercus restoration.

Ken

Originally Posted by neksmerj

I'm now using only two ms electrodes, each about 100mm x 100mm, and am attempting to clean both lathe bed feet at the one time.

Initially the current draw was zero until I gradually added some dissolved washing soda (Lectric soda crystals). Steadily the current rose and is now sitting on roughly 3 amps.

Q1. Can I expect this process to remove the paint along with the rust?

Q2. How long will this process take, hours, days, weeks?

I'm getting all the froth and bubbles, so things are cooking.

Had to put a cloth over the tub to stop puss from drinking out of the tub. Didn't know cats like water, mine does.

I'll keep updating as things progress.

There's a couple of snaps just to keep AB from winging that I don't do anything on my Hercus restoration.

Ken

If you start with clean surfaces, ie remove all oil and grease and if the rust is only surface rust, using 3 A you should get pretty well all the rust converted to FeO with 24 hours. If you want to be sure you can got to 48 hours. For thick ie mm scale, it can take 3-4 days at 3A - maybe up the A for this level of thickness.

I would be very wary about putting any sort of cover on the container as that may trap some hydrogen and oxygen.
Bubbles should be minimized as they will also trap some hydrogen and oxygen.
A while back I posted about a small [non-lethal] explosion that a poster in Home shop machinist experienced with too many bubbles and a short.
Make sure you disconnect all power etc before moving/removal of objects being treated.
For the information of others, Battery/crocodile clips can easily slip off and make sparks - connect my wires firmly with nuts and bolts so connections can't just slip off (just like you did).

Once it is done have your next treatment phase ready because the raw metal will start re-rusting in minutes.
Boiling in pure distilled water is a a good treatment - water must be ready and boiling furiously when object is put in.

Will it take the paint of , it might - depends on the type of paint and length of time used.

If you want to strip the paint off, and remove the rust , use Caustic Soda as the electrolyte . But don't get it on exposed skin, it burns .

It also helps to use hot water to begin with, this speeds up any chemical reactions .

Mike

Hi, Just a note about using this process. Hydrogen embrittlement is a side effect that increases with time spent in the process. I've had good items break in my hands from leaving them in for too long.
The solution is to bake the parts in an oven for a few hours after the process.
I don't pretend to know all the science involved but there is plenty of info on the web.

At the risk of boring everyone sh*tless, a quick update.

I did not leave the process running overnight, in case something went wrong. So far, no smoke. Power is back on now.

The paint is lifting off, and in light of what Morrisman suggested, could the stripping process be speeded up by also throwing in some caustic soda into the mix.

I ask not knowing if mixing the two chemicals together could be dangerous. ie washing soda and caustic soda together.

If I risk blowing up half the neighbourhood, maybe I should tip out the electrolyte and start again.

So far so good.

Ken

I sometimes wondered what the difference was, so I had a bit of a search...and I think it wouldn't matter.

"The difference between baking soda and washing soda is water and carbon dioxide.
Baking soda’s chemical makeup is NaHCO3 (1 sodium, 1 hydrogen, one carbon, and 3 oxygen molecules).
Washing soda’s chemical makeup is Na2CO3 (2 sodium, 1 carbon, and 3 oxygen molecules).
When baking soda is heated up to high temperatures, it breaks down to become washing soda, water steam, and carbon dioxide."