Electrolysis Advice (1 Viewer)

[coinoperated40]

Is it OK for the copper lead to be in the solution? Looks like it is, but can't really tell.

 

[Cruiserdrew]

Is it OK for the copper lead to be in the solution? Looks like it is, but can't really tell.

On the cathode, yes. If it's the positive lead, it will dissolve like the sacrificial steel rods.

 

[Coolerman]

Excellent idea securing the re-bar using the wire tie through the bucket and the wire nut to tighten it! I'm stealing that idea...

 

[Vae Victus]

Just found another excellent write up on Electrolysis, even more detailed than CoolerMan's (though we love you more Coolerman!)

http://users.eastlink.ca/~pspencer/nsaeta/electrolysis.html

Lots of good into, discussion, explanation, ideas. Reading it as I type this.

Just bought a BIG container to clean larger parts at Wallyworld. (Went to buy ammo, as it was rumored to be available again. This being one in a bad area, the ammo section was pitifully small, and no pistol ammo. But saw the container and remembered i0I needed one for parts cleaning).

 

[Vae Victus]

Looks like you have nailed the electrolysis technique. As early as you are in your project you could easily step up to a larger tank (rubbermaid totes work well). I agree that you should lose the plastic short protectors. I never found shorting to be a problem. I also got lazy and would often remove the parts , rinse them and use a hand brush to reveal fairly clean metal and shoot them with WD-40. That preserved them until I was ready to break out the grinder with a wire brush to prep them for primer. I would degrease them, wire brush them, degrease them again and etch prime.

Craig, be careful about shorting stuff out, I quote from the article posted above: "You could use a copper, stainless steel, steel or cast iron bucket, sink, pot etc. connected to the POSTIVE post as long as you are careful not to let the part being cleaned touch the side of the bucket (short circuit will occur)."

 

[Vae Victus]

A couple of significant quotes from that article:

the US Occupational Safety & Health Administration has a considerable write-up on Hexavalent Chromium (CrVI) and say CrVI is produced from the high tempertures produced when welding, grinding or melting stainless steel or other metals containing chromium. This has been echoed by people I have spoken to about this, all experienced, qualified PhD Chemists and Materials Engineers. I now believe that the temperatures that occur with electrolysis as described herein are not nearly high enough to pose a risk. If you disagree, send documentation written by qualified experts that address the process of electrolysis in a water bath. Heresay and rumours just don't cut it. The concesus among my learned friends is that there may bo NO hexchrome created in a water-based electrolysis bath, the temperatures are far too low.

But, use stainless at your own risk. Use in a well ventilated area. Also, don't weld stainless without a good breathing filter apparatus.

And

» A 12 volt battery or other DC power source with high current capability. A battery (in conjunction [parallel] with a charger) will always give superior results. A trickle (4 to 12 amps) battery charger can be used for small parts. A shop grade "booster" battery charger is quite effective for even large parts. 6 volt DC works as long as the current ability is high enough. Higher voltage DC sources will work of course BUT then it becomes a shock hazard. (see safety rules below) but moreover, higher voltage increases the risk of hydrogen embrittlement.

If you use a battery charger in combination with a charger, it is best not to connect the battery in SERIES with the charger since the highest current available is limited to the capacity of the charger; i.e. you can't push 100 amps of potential available battery current through a charger with a 10 amp capacity.

So use a 12v battery in parallel to clean up the DC power and get better, less pitted results.

Finally, don't use a wire wheel at all if you can help it.

Bill McCabe above explains it this way:

I know wire wheeling after electrolysis makes them look great, but you're burnishing the surface which is harder for paint to adhere to. The surface that comes out the tank, followed by the zinc phosphate acid treatment such as Metal Ready is an ideal paint surface. In fact I'm convinced wire wheeling is the worst way to clean rust off metal. Under an electron microscope, surface rust is going to look like Manhattan made out of jagged metal. Wire wheel flattens that out by folding it all over leaving tiny pockets of air and rust that are not visible to the naked eye. Looks great, just waiting to start rusting under your paint. POR advises against wire wheeling for any of their rust products.

 

[sarca]

Thanks for the encouragement - when I first looked at electrolysis; I was overwhelmed. It wasnt until Vae Victus' thread helped me to entertain that I could do this. (For those of you who dont know, I am a beginner mechanic - and I do mean BEGINNER!! The huz teaches me engine, mechanics, and how it works - but he detests body repair)

So in my typical learning fashion, I springboarded from this thread, to Coolermans and then I incorporated this Youtube Video on Electrolysis and finally an Instructable Step by Step . I needed a whole lot of knowledge and explanation and between all of these - this is what I made.

14 gauge Primary Wire Copper Insulated Wire (Red)

Steel Wire

5- 1/2 inch Rebar

Battery Charger (Kmart on sale $35) With adjustable 2-6 amps and 6-12 volts

View attachment 786432

I drilled holes in the bucket to pull the tie wire through and secure the rebar to the sides. (I wasnt too concerned about how much longer the rebar is than the bucket - especially they are considered sacrifical and assuming that this experiment worked - then I was automatically moving to a bigger tub.)
Initially the holes I drilled were 1/2 inch apart - this turned out to be too far apart - if I wanted to SNUGLY secure rebar.


Utilizing x-x-x-x-x I used the red insulated wire on the rebar, using an orange wirenut to designate the 'ending' and plus - the red wirenuts were to big for just the steel wire and one section of red wire. At the 2nd, 3rd and 4th I moved up to the red wirenuts as they were bigger and could hold joining 2 sections of insulated wire AND the rebar tied wire. The 'beginning' connection, I left red wire hanging from the wire nut exposed, to connect to the battery charger.


Using previous suggestions, I marked "2 gallons" on the outside of the bucket and dumped approximately 2 TBSP of of Arm N Hammer Soda in the bucket

The charger (unplugged, unpowered!!!) Red "hot" charger connector went to exposed hanging red wire. The black Charger (negative) had to be connected to the bracket I wanted to de-rustify I was so eager to get started, and I didnt want to use the copper wire, so I connected the negative cable to some of the steel tie wire, dangled it from a (non conductive, of course) plastic hanger


And thennn...

 

[sarca]

The black negative connected to tie wire, and then to another clamp which was in turn attached to the rusted bracket.( I wanted to specifically show this as this is where I was a little unsure in execution) The plastic hanger will be replaced as it is not stable enough..I have a bunch of granite slabs that are 2 inch by 24 inch - Ill probably one of them to secure the negative over the bucket.

Using the steel tie wire, there is no copper in the water solution.


Here are pics of the rusted bracket before



Connected all wires, suspended the rusty bracket in the water solution - and hit the power. The bubbles started slow at the 12V-2A setting..after about 10 minutes, I flipped it up to 12V-6A and it really started cooking - bubbles I'd liken to simmering water from the rebar pieces and the rusty bracket. I let it cook for an hour..

 

[sarca]

After 1 hour - below are the results. I was floored, flummoxed and seriously impressed When I pulled it out I initially used a wire brush - (against some opinions) But it was pretty darn obvious that most of the crap rubbed right off. . so I tossed the wire brush - wiped it down- washed it-dried it with a hair dryer-then I hit it with Rustoleum Professional Primer..two coats.
24 hours later its obvious that I shouldve used something to efficiently coat the surface before laying primer..This particular detail will require more research
I know some of these are repost from my inital post...but I wanted to explain it in the easiest way...so someone like me could read and understand.

 

[Cruiserdrew]

That's great. I'd let that piece go a bit longer but you're on the right road here. The step you left out is the metal passification step.

When I get parts out of the solution, usually everything left comes off with a bit of a rub down with some scotch-brite stripping pads. Anything that's black where the rust used to be, is good-that's magnatite and will not promote further rust or scale. Then coat the metal in metal prep and prime (like Ospho or equivalent) let it sit for 30 minutes and then wash off and dry completely. That step converts raw iron on the surface to Iron Phosphate which is also stable and a perfect surface to hold paint. It also prevents the flash rust you get otherwise.

I have done items as large as a 3 burner coleman stove case. You just need a bigger vessel, more electrolyte and more annode material. I have been using the old crapply leaf springs I have around.

Electrolysis is the only way to convert and remove rust that removes absolutely no good metal. You do need a very high pH solution to protect the good metal in the solution. You will get better results using Sodium Carbonate vs Sodium bicarbonate (baking soda) and even better results with Sodium Hydroxide (Lye). Unfortunately that makes a very toxic dangerous to handle solution and so I see the Sodium Carbonate (washing soda) as a good compromise.

After a few rounds the electrolyte solution will look super funky-like rusty sewer water. It's still good. Let it settle, siphon off the electrolyte from the funk and re-use.

 

[sarca]

Thanks man! Great ..Im going to do all my small parts before I paint the body over the next few weeks.

Im planning on going to habitat 4 humanity and looking for a cheap large rubber tub - depending on how my hardtop pieces look. Had some severe rust along the hatch crossmember but otherwise, it doesnt look too terrible.

Thanks again to all the contributors...Mud Rules!

 

[Vae Victus]

I read somewhere that I can't find now, that the ideal amperage is 6-7 amps (if you are using a charger that shows the amperage). The way to dial that in is with the amount of electrolyte in the water. Start with very little electrolyte, and keep adding it until you get up to around 6 amps on the meter. This assumes that you have a charger capable of more than 6 amps.

Roughly 1 tbsp per gallon if you don't have a meter seems to work fine.

I'll try to find that reference since I'm spewing stuff that I can't verify.

 

[Vae Victus]

Read that putting copper in the solution (ie in the alligator clips) is bad, and read the opposite.

Which is it?

 

[Vae Victus]

Hmm, wonder if I can find any waste rebar around my house.

 

[sarca]

Read that putting copper in the solution (ie in the alligator clips) is bad, and read the opposite.

Which is it?

I saw both views too and refrained from using copper in the solution to be safe.

 

[Coolerman]

Don't use copper, it will actually microscopically plate itself to your part enough to have a "dissimilar" metal corrosion issue.

The amperage that flows is directly related to the size in sq inches of your part, the size in sq inches of your anodes, the distance between the part and the anodes, the voltage applied to the system, and the amount of sodium bicarbonate or what ever you use in the solution. You can easily control the amount of current by inserting one or more +12V light bulb in SERIES with the cathode or anode lead. The bulb acts as a current regulator and also gives you a visual indication that the system is working.

In the pic is a tank I "built" for de-rusting drag links and other long skinny parts by laying a garbage bag inside a long cardboard box, filling with electrolyte from my main tank, lining the sides with pieces of old computer cases, then laying the part on the bottom with plastic insulators. ( The orange insulators are re-bar caps!) You can see the blue light I was using to regulate the current. The current was too high due to the rods being very close to the bottom anode. The bulb regulated it down to about an amp (depends on the wattage of the bulb used).

 

[sarca]

Coolerman, you're my hero.

 

[Coolerman]

Just KY ingenuity and a lack of funds!

 

[Vae Victus]

Coolerman, you're my hero.

I agree. Now, where is that tranny rebuild how-to? I'm lost without your guidance.

 

[sarca]

Just stopped to give a great thread a bump - Ive got more parts 'cooking' today. I went with the suggestion of adding baking powder as the last step to level up the amps more evenly and I picked up some Ospho. Ive got a non cruiser related project that has me debating a larger 'tub' for electrolysis. Might take a trip on down to the habitat and see what I can find!