Electrolysis - Thank You All

[8man]

I got another of Grandad's old vises from my Dad. This one is a pipe vice and I'm doing it for my Dad. When I picked it up from him, it was so rusted that I didn't think there was much chance of cleaning it up. So I put it in the electrolysis bath for 48 hours and WOW, what a difference.


I used a rubber mallet and whacked the handle lightly 2 times and the handle broke loose. A couple more times and the main bolt broke loose and I could raise it and lower it. When I get some more time I'm going to "bathe" it some more and then wire brush it to clean it up and paint it.

Now for an electrolysis question or two.

1. I used Tri-sodium Phosphate in the bath (got it at a Big Box). I've read to use washing soda. Is there any difference in the outcome?

2. Since the rust was BAD, would leaving it in longer help?

3. My old Sears battery charger goes up to 8 amps. When it started the soak, it registered "Taper" or less than 2 amps. After 24 hours it was up to "Taper or less than 4 amps. By the time I pulled it after 48 hours it was up to almost 4 amps. Is that normal? Did I have it hooked up wrong? should the amps have been higher from the start if I had made a better connection between the vise and the wire?

I want to thank all of you who have written about electrolysis. I would never have thought I'd have this vice actually working in 48 hours. It's not pretty yet, but it worked. The threads on the main bolt were really rusty, yet after the electrolysis once they started to move, it worked all the way up and down. The handle was rusted in place, but now it slides through like it's supposed to.

So thanks to all that have helped!

 

[YukonXL04]

From my experience with it.
The amperage will go up because the longer it sits the more resistance forms in the charger connections because they start to corrode. Clean them once a day or so.

I used washing soda and it worked well for me. Cleaned a old cast iron fireplace parts up pretty good. This thing had been sitting outside for 30+ years when I got to it so it was really coated in rust. Ultimately I broke down and bought a sand blasting unit instead though. But it was a large project.

Good luck

 

[Lassen Forge]

I've been playing with this for a few weeks now with an old 2a charger, using some old mild steel rods for cathodes (the part hooked up to the red clamp)...after a few days they get rusted to heck, an i dry them and hit them on a wire wheel... it takes 90% of the work out of it, and i have 90 year old parts that clean up looking like new steel... just the ticket fur those rusty antique tools - i may have to take some before and after shots.

I read somewhere about "hydrogen embritlement" when doing this, tho, so is it a problem, and can it be counteracted? i don't need my bike front end failing on me!!!

 

[metalmagpie]

Use washing soda rather than TSP.

I have burned out two small battery chargers. I don't think they are really built for continuous service over several days. You can do what you want, of course, but I
decided to buy a proper DC power supply. I would use quite a bit more current if I
had to do a post vise. Maybe 12-15 amps.

Hydrogen embrittlement could be a factor depending on what you're derusting. Think of it this way. A steel thing at the atomic level looks like a bunch of tennis balls stacked up. Then it gets exposed to a bunch of marbles (hydrogen atoms). They work their way into the crystal lattice and stay there for awhile. But, being really small, they continue moving and generally move back out again (escape) or diffuse all throughout the steel where they are in very low concentration and not enough to do any damage. You can bake your parts which is like making all your tennis balls a bit farther away from each other, letting they hydrogen concentrated at the edges move more easily. Not generally a problem.

metalmagpie

 

[8man]

Thanks guys, that is exactly the type of info I need.

Metalmagpie, what type of DC power supply did you go with?

 

[jkwilson]

From my experience with it.
The amperage will go up because the longer it sits the more resistance forms in the charger connections because they start to corrode. Clean them once a day or so.

Increased resistance would cause the current to drop. Cleaning the electrodes is still a good idea.

 

[E.Marquez]

Consider using carbon electrodes, it leaves almost NO coating that must be removed in a second operation.

I buy them in bulk on ebay for cheap.
Use the Arm & Hammer washing powder, or HDX pH+ Sodium Carbonate from Home Depot

 

[8man]

I got Arm & Hammer Washing Powder and the carbon plates for sacrificial electrodes. The "soup" seems pretty clean compared to what I've read.

I'm still interested in what to use other than my old Craftsman battery charger for a power source.

 

[exmaxima1]

I'm still interested in what to use other than my old Craftsman battery charger for a power source.

I hooked up a tank for some vises a few months ago and made some current measurements. I started out using an Radio Shack 12vdc bench supply rated for 3 amps. With 5 anodes the draw was about 3 amps. So I then tried another supply rated for 30 amps, but the draw remained the same.

This is not surprising since it is the VOLTAGE that limits the current. Since both supplies were 12 volts, they pushed the same current. If anyone wants to try running their tanks at higher currents they will either need more volts or reduce the resistance. Moving the proximity of the anodes closer to the cathode (rusty part), or possibly better electrolyte, reduces the resistance.

I used sodium carbonate, but maybe there are more efficient solutions. I think that using a higher voltage would be easiest.

 

[AMCguy]

You will have good luck by observing a couple of rules of thumb.

Have a sacrificial anode array that is as large as practical. Not bulky but but as large a grid as you can get. Try to surround the part being cleaned. If the object is hollow try to get an anode right inside. The idea is to have many lines of sight for the current to flow. I have found the best cleaning action is line of sight.

You have to use washing soda. You get more current to flow the more you add. I used an 8 amp charger for a while. It was putting out the full 8 amps. It was so cool to see it working the second I turned it on.

I've only done small parts and tools to date, but when it warms up a bit I'm going to be doing and engine block I'm hoping to save. I have an old stick welder that I'm going to try using as a power supply.

 

[dogdog]

I got Arm & Hammer Washing Powder and the carbon plates for sacrificial electrodes. The "soup" seems pretty clean compared to what I've read.

I'm still interested in what to use other than my old Craftsman battery charger for a power source.

I have done about five 50-60's style radiator about 100 lbs each this Summer. took about 1 week each.... side by side between the craftsman 200AMP manual charger and the HF charger 2/10/50 AMP... and an 24v 12.5 AMP inverter power supply from medical surplus... The HF unit kick *** in over all performances, but I did have to replace that 20AMP automatic reset fuse inside because the ones comes with the unit burned out. otherwise it out performed the craftman. The 24V inverter Unit worked on the ones that most rusted that either HF/Craftman unit's won't do cause layers of old lead paint and rust on it, and was afraid of too much voltage generated Hydrogen that it would embrittlement on these cast iron... but at end of day it cleaned it pretty well after 3x tubs of water change each. Remember reading on some forum that this action is almost like line of sight so the farther away the rusted part from the electrode it will take forever and almost never get to it... you'll have to move the electrode around some times. and more electrode will draw more current as well....


the sears one is this one. now discontinued.
http://www.sears.com/diehard-gold-wheeled-battery-charger-with-timer-control/p-02871240000P

the HF unit is this one.@ 10AMP setting.. just make sure you change out the internal automatic reset fuse when it blows requires drilling off the rivet, (you''ll see everything working except no voltage on the output).... it's cheap fuse so it will burned up after few use but it's at $3.99 for a quality brand item from auto zone.

http://www.harborfreight.com/10250-amp-12v-manual-charger-with-engine-start-60581.html

The 24v inverter base medical surplus is from e-bay... make sure the fan is running. I almost had electrical fire cause I forgot to hook up the fan...obvious a long lead to keep it far away from water and moisture.

Astrodyne MMK320S-24
http://www.astrodyne.com/products/data-sheets/mmk320/

 

[metalmagpie]

Sorry it's taken a bit to reply. The power supply I use now is this one:
http://www.mastechpowersupply.com/v...30a-over-voltage-over-current-protection.html

I started out using steel for anodes but got frustrated when the rusting slowed the process. Then I tried graphite electrodes obtained from an EDM shop. They worked OK but got eaten away and the solution turned inky black. To be fair, I may have run them at too high a current, don't know. At any rate, I started using lead sheet and it seems to work great. The lead sheet discolors but the process doesn't slow down, and the solution remains crystal clear. I use strictly washing soda and water for the bath.

The easy way to clean dirty anodes is to reverse the connection and let electrolysis clean your dirty plates. I do that with my lead sheets every so often. I did a lot of electrolytic derusting in a recent project which I also wrote up. Have a look:
http://nwnative.us/Grant/shop articles/MEC275/projectWebPage.html

metalmagpie

 

[8man]

Thanks guys, great information.

 

[AMCguy]

Great write up metalmagpie.