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Old 10-09-2006, 05:14 AM
LW Hiway's Avatar
LW Hiway LW Hiway is offline
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Default Using current to remove rust.

First off let me tell you, this process kicks butt for rust removal. If the item is made up of several items as in an assembly, it will work wonders. More so than blasting with sand or other grit materials. But remember, it's not an instantaneous process. It is for those projects of rusted worth that blasting or other cleaning methods would degrade or ruin the piece. It works well, but does so methodically.

It was a simple task to make up the connectors. But as usual and being the anal-retentive that I am, I used crimp connectors and couldn't bring myself to not solder the connections anyway.

I used what wire I had as I didn't feel it necessary to open a new roll when I had several feet rolled up and hanging on a nail.

The barrel is of the chemical type made of thick and fairly hard plastic/PVC/rubber(?) (they were free and don't glow in the dark anymore). Fairly sturdy for it's thickness.

Just make sure you cut inside the top and not on the outside of the top. Cutting inside the top allows the top ring to assume a stiffener type roll and keeps the barrel top "in the round". Other wise, the mouth will collapse in some instances, making it less useful.

Nothing special was done to the rods prior to welding the bolts. Just MIG'd the bolts at a 90 deg to the rods.

I had 3 pieces of 6' re-bar about a 1/2" in diameter. Cut into 24" lengths. Giving me 9 total pieces. I spaced the rods/holes on the barrel close to 9" or so and the spacing looked about close enough for the eye.

The height of the holes leaves about 2" of clearance from the bottom of the tank to the bottom end of the hanging rods. I allowed for the rods to not rest on the side of the barrel. I guess I wanted to have the complete circumference of the rod to be available to the solution.

Pics 1 and 2 show the wiring and rods with the final water level. Yes the rod ends are painted red to make sure the "charger hooker upper" makes sure to use the positive clamp.

I made a dash Saturday evening to Walmart and picked up a large box of the Arm and Hammer washing soda powder and a few boxes of the regular soda as well. Guess I wanted to see which would work better.

Ok, final check, rods bolted to the barrel, check.

Positive wire ends soldered and tight to the rod studs. Check

Fill the barrel with water and add 3 scoops of soda washing powder and a dash or 2 of the regular soda. (hell with using one or the other). Check

Try not to agitate the soapy water mixture while it is filling up. Let the hose and water swirl the mixing. You'll be scooping a cubic yard of suds if you do.

I kept the water level about 3" below the rod bolts just for leaks sake. I didn't seal the holes other than using a large area washer inside and outside of the barrels wall. No sealant. I wasn't making a submarine.

The battery charger was one bought from NAPA about 35 or so years ago and has had two different generations of puppies chew the cord and leads off but has been repaired several times. Dogs are gone now, but I've still got the charger with teeth marks and newer clamps and electrical cord. lol

The charger is of the low amperage type with a 6 volt/12 volt switch, some would call it a "trickle charger". I opted to use the 6 volt setting as the 12 kept the meter peg'd and the charger hum'd. 6 just felt better. I want to use the charger again. Note: While the charger was set at the 12 volt setting, I did notice that the action of the process was more pronounced in the amount of bubbling showing on the surface.

I dropped the rim into the solution allowing for it to be close to 3" or so below the surface. Making sure that I could swing it in all directions and it would not hit the anode rods. No problem. Having the metal to be de-rusted well clear of the anode rods is a must. Intermittent contact is not good for the charger and you can't see the sparks in the water/solution anyway.

Using an old pair of vice grips allowed for a good connection to the rim as well as a good place to attach/connect the negative lead for the charger. Welding a 3/16" bolt did the trick.

Before anyone says anything about the color of the ground wire, it is black, I can tell it's black and I'm telling you that it is black. So just except it as being black. It is a twisted black freakin wire.

Now while the rim looked in pretty rough shape initially, understand that this is a spare tire rim for the on the farm only trailer. It may see road use, but only being pulled with a tractor at tractor speeds and seemed to be a good candidate for this exercise.
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Last edited by LW Hiway; 10-09-2006 at 02:39 PM.
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Old 10-09-2006, 05:16 AM
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I placed the rim into the solution and hooked up the battery charger at 1am Sunday morning. Taking a few pictures at different times shows the bubbling effect and discoloration of the suds produced. Fairly colorful if you like old rusty things.

The following pics allow you to see the action of the anode rods as they are in the sacrificial process.

I took a nap between the 10th and 16th hour pics. I was getting tired watching red bubbles.
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God, if you would grant me one request through Prayer, please help me be the Man my Dog thinks I am. Please.

Quoting "The Hunt". "A man will walk into hell with both eyes and arms wide open. His dog will know better."

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Old 10-09-2006, 05:18 AM
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The last 3 pics are of the rim after it was removed from the barrel.

As I'd read, it was covered somewhat with a soft surface slime. Some of the old rustoleum was soft and brushed off easily. Some of the old primer showed good adheasion to the surface and did not brush off.

I did note that if I had pulled the rim, wire brushed it and placed it back into the solution for more cleaning that it would totally remove the evidence of rust, not the pitting, just the surface rust.

As I was running out of time and needed to head back to Lake Charles, I cleaned the slime and loose coating, dried with compressed air and a Mapp torch and brushed OSPHO on it. It's keep till next weekend.

Note that the last pic shows how well the process works. It hardly looks to be the same old rim.

Enjoy.
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God, if you would grant me one request through Prayer, please help me be the Man my Dog thinks I am. Please.

Quoting "The Hunt". "A man will walk into hell with both eyes and arms wide open. His dog will know better."

I never thought I'd live long enough to become a grumpy old bastard. Here I am, killing it!

Last edited by LW Hiway; 02-06-2010 at 12:34 PM.
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Old 10-09-2006, 06:24 AM
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The rim-to-vise transformer secret is out.

The to converter must remain a secret.
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Old 10-09-2006, 11:10 AM
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Very cool read here lwhiway. I can see where wirebrushing between soakings would be of some benefit, removing the thicker, less-attached material to flake off and expose new area.

My basic understanding of the process tells me that the rust transfers itself from the negatively charged piece onto the positively charged rods, correct? How badly were they covered when you were done, or was most of the rust still trapped in the solution?

How do you reckon this process would work with pieces that had been previously chemical treated, for example a chrome rim? Would the chrome be stripped or just the rust?





I don't have a vise at all, and it'd be pretty blingin' to have one of chrome!
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Old 10-09-2006, 11:32 AM
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Quote:
Originally Posted by dubby

My basic understanding of the process tells me that the rust transfers itself from the negatively charged piece onto the positively charged rods, correct? How badly were they covered when you were done, or was most of the rust still trapped in the solution?
The positively charged rods are sacrificial; they will not only be covered with rust, they will erode dramatically.
Accidentally hooking the leads up backwards will result in severe pitting of the wrong object. The best
stock for this use I have found is old lawnmower blades; they are not good for much of anything else. After
you use them for derustifying something they are not good for anything.
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Old 10-09-2006, 12:42 PM
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Okay, been thinking about this more.


Looking at lwhiway's setup, I notice that all the rods are chained together electrically on the outside. Having multiple rods to attract (and sacrifice) makes sense for a number of reasons, but wouldn't your setup be more efficient if all the leads were the same length, and connected to power at a central point? Seeing how electricity seeks out the shortest route to ground it seems that the voltage would drop before all the anodes were charged. Or am I just making it more complicated than it has to be?
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Old 10-09-2006, 02:59 PM
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Dubby, from what I've read on the subject, discussions on this board way back when and a few articles written by a few folks across the www, some seem to think that the process will not remove chrome that is still bonded to it's surface.

I did notice and did say that I saw well cured red rustoleum primer (thick and 10 years old), softened to the point that it easily scrubbed off with little wire brush action.

Another point to note, although the pics were taken at night, there were a few spots that had no rust at all and the metal in those spots were shiny as if the paint were chemically stripped. I'm assuming that the rim was clean and totally free of rust when it was primed so many years ago and that the primer had protected those spots completely.

On de-rusting chromed parts or rims. I'm reading that it can be done, as the process attacks/works on the rust only. But, be aware that they/some say that if the plating is somewhat loose or pealing on edges where the chrome has been marred, scratched or compromised in it's bonding and there is the formation of rust underneath the layer of chrome to the metal, some of the chrome may show further signs of lifting/pealing.

Not being the expert here, my suggestion would be to not de-rust items that you have not first done a few exercises before hand to better understand the process and it's effects on different objects of worth.

With it being so late last night, Sunday, I did not have much of a chance to do any looking at the rods and the activity of the process. Basically, my hands were washed after cleaning the rim and I didn't want to stick them back into that rusty colored mess. lol

But, looking at the Pic that Cutter offered, it's obvious that the action will reduce the anode to a state of invisibility after a few uses.

On the solution mixture and what to use, I would assume that pure Arm and Hammer soda in the box normally found in the kitchen or refrigerator for freshness would/will work readily, but that the washing powder might do better if as much old paint etc is to be removed as well. Further use will determine this.

LW
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God, if you would grant me one request through Prayer, please help me be the Man my Dog thinks I am. Please.

Quoting "The Hunt". "A man will walk into hell with both eyes and arms wide open. His dog will know better."

I never thought I'd live long enough to become a grumpy old bastard. Here I am, killing it!
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Old 10-09-2006, 05:46 PM
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GWIZ GWIZ is offline
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Quote:
Originally Posted by dubby
Okay, been thinking about this more.


Looking at lwhiway's setup, I notice that all the rods are chained together electrically on the outside. Having multiple rods to attract (and sacrifice) makes sense for a number of reasons, but wouldn't your setup be more efficient if all the leads were the same length, and connected to power at a central point?
Yes if he was using Hi current like over 100 amps.
The resistance of the wire would come into play.

Quote:
Seeing how electricity seeks out the shortest route to ground it seems that the voltage would drop before all the anodes were charged. Or am I just making it more complicated than it has to be?
Electricity does NOT seek out the shortest route to ground.

The current to each rod would be divided in proportion to the resistance of the wire to each rod, and the resistance of the liquid to the location to his part to the rods.
The resistance of each wire would be so low that calculating the current drop to each rod would not be worth the time.

=======
NOTE. I'm not an expert.
But when placing two electrodes of different polarity's in water, you will separate the oxygen and hydrogen from the water.

Hydrogen is explosive. It gets worse if you do this in a confined space like a garage.
(Look out for the water heater).
Samething as a car battery when its getting a charge, the bubbles are hydrogen and oxygen gas.

You don't want to be sparking your wires. if You get enough concentration of hydrogen gas you will blow your self up with the house.
Or you may find your self in the burn ward of an hospital.
And people making jokes about barbecue sauce.
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Old 10-09-2006, 06:26 PM
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Quote:
Originally Posted by GWIZ
Electricity does NOT seek out the shortest route to ground.

The current to each rod would be divided in proportion to the resistance of the wire to each rod, and the resistance of the liquid to the location to his part to the rods.
The resistance of each wire would be so low that calculating the current drop to each rod would not be worth the time.
Electricity finds the easiest route to ground. The soda and water solution is not the best conductor so the current will be relatively well dispursed across the electrodes.

Quote:
Originally Posted by GWIZ
NOTE. I'm not an expert.
But when placing two electrodes of different polarity's in water, you will separate the oxygen and hydrogen from the water.
Electrolysis is the term for separating hydrogen and oxygen from water, not the most efficient method from an energy stand point. There is a minimum voltage required to perform this, can't recall the value right now, guess I have to pull out the old text books for that one.
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