electrylosis

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  #1  
Old 09-10-03, 04:38 AM
boman's Avatar
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electrylosis

Need to know if anyone has experience with this method for cleaning metal. Not sure if I spelled it right for this application. I do not mean hair removal. I thought I read a post here about this procees to remove rust.

On anther note, I came across an article explaining how something similar to this can cause problems with some vehicles' cooling systems if the vehicle has a loose ground somewhere. Something to do with the small current in the coolant looking for a ground and causes the cooling system to rust. Anyone else know of this?

Article:

Electrolysis Problems Continue to Mount
There's a Downside to the Electronics Revolution


--------------------------------------------------------------------------------

Nowhere is the impact of electronics more obvious than in the automotive world. Today's cars and trucks are packed with motors, sensors, and task-specific microprocessors, and while the gadgets are interesting if not always practical, they have greatly complicated the task of diagnosing and repairing today's vehicles. In fact, the proliferation of electronic gadgetry, under the hood as well as under the dash, has triggered a whole new set of vehicle problems and diagnostic challenges.

Take electrolysis, for example. Before the days of front wheel drive and transverse-mounted engines, cooling system electrolysis was a rare occurrence. But today, with most cars and many light-duty trucks featuring electric cooling fans in conjunction with ungrounded plastic-tank radiators, cooling system electrolysis is becoming a frequent problem.

Electrolysis occurs when electrical current routes itself through the engine's coolant in search of electrical ground. Current can be introduced into the cooling system in many ways, but the two most common causes are a poor ground to the radiator's electric cooling fan, or a poor ground from the starter motor and engine block to the battery. Any vehicle with accessories bolted to the radiator support or to a nearby component is also a good candidate for electrolysis.

The Causes and Effects of Electrolysis

Electrolysis is a fast-acting menace that attacks not only radiators and heaters, but can destroy an entire engine in a mere 20,000 miles. Though a small amount of measurable voltage can be detected in most engine cooling systems, due to reactions between the coolant and cooling system metals, the detected voltage should never exceed a tenth of a volt in vehicles equipped with aluminum engine blocks and/or cylinder heads.

Cast iron engines and cooling system components can tolerate higher stray voltages, perhaps as much as three-tenths of a volt. But that doesn't mean three-tenths of a volt is acceptable. It's not.

In cases of electrolysis, a defective or missing ground on an electrical device causes the electricity to seek the path of least resistance whenever the component is energized. Sometimes the path of least resistance is a radiator or heater hose, or the radiator or heater core. As the current draw of the poorly grounded accessory increases, so does the destructiveness of electrolysis.

A poorly grounded engine and starter motor can zap enough current through the cooling system to blast apart a heater or radiator in a matter of weeks or even days, depending on how often the vehicle is started. A partially grounded electric cooling fan, on the other hand, may only shoot a small percentage of its supply voltage through a cooling system, and the effect may take months to reveal itself.

Evidence of electrolysis includes unexplained and/or the recurring pinhole leaks in a radiator or heater. Pinholes may form anywhere along the tubes or tank walls, but damage is often concentrated at tube-to-header joints, or in the tube walls near the center of the core, where the electric cooling fan mounts come in contact with the core.

Simple Shop Test for Electrolysis

To test for electrolysis, connect the negative probe of a digital D.C. voltmeter to the battery's negative post. Then submerge the meter's positive probe into the coolant at the filler neck. Be sure that the positive probe does not touch any metal.

Next, note the meter reading, which should be no more than 0.10 volts. If a higher voltage is detected, methodically shut off or disconnect one electrical component or accessory at a time while watching the voltmeter. When the voltage reading drops to zero, you've pinpointed the electrical component with the defective or missing ground. Since electrolysis might occur only when a certain component is energized, have a helper switch each vehicle component on and off while you observe the voltmeter readings.

To check components or accessories that don't have an on/off switch, use a long jumper wire connected to the battery's negative post to provide a temporary ground to each electrical accessory. Ground each component with the jumper wire and watch the meter. If the jumper wire restores a missing or faulty ground, the meter will drop to zero.

Be sure to check for intermittent voltage surges generated by the starter during cranking. To do so, watch the meter as you crank the engine. Any jump in voltage during cranking indicates a loose, faulty, or missing engine ground. Any electrical device with a huge current draw, like a starter motor or radiator cooling fan, will chew up a cooling system far faster than a trickle of voltage from a poorly grounded underhood relay or other low-amperage device.

Static Charges: A Second Cause of Electrolysis

A small number of electrolysis problems have been traced to static buildup somewhere in the vehicle. Likely sources would be rubber-mounted driveline parts, a plastic blower wheel spinning in a plastic HVAC case when the blower motor is improperly grounded, and certain tires. In fact, not too many years ago, Michelin received a rash of complaints from vehicle owners who were getting zapped whenever they stepped from their vehicles. The problem was traced to the tires, which generated a static buildup in the vehicle when driven under certain conditions.

Some of the newest vehicles coming off the assembly lines feature a different type of blower motor circuit which may actually increase the incidence of electrolysis caused by static discharge. Conventional HVAC blower motors are usually wired so that the motor is always grounded and speed is controlled by applying battery voltage to the positive terminal of the motor. Speed is varied by routing the battery voltage through a series of resistors before it gets to the motor. Some newer vehicles, however, are wired so that the HVAC motor is always "hot" with 12 volts from the battery. Speed is controlled by applying a variable ground to the ground-side terminal of the motor.

When an HVAC motor is always grounded, static charges that might form inside the HVAC blower case are likely to "zap" the motor's housing and then be routed harmlessly to the ground post of the battery. But on vehicles with a variable ground to the HVAC blower, static buildup has nowhere to go, or at the very least it must overcome higher electrical resistance as it travels toward the best available ground. By "best" we mean the "path of least resistance," a key concept in electronics and the diagnosis of electrolysis. Don't Ground the Heat Exchanger!

Early on, when electrolysis first cropped up as a problem in cooling systems, many mechanics attempted to solve the problem by grounding the heater or radiator in order to "collect" any stray voltage and route it to battery ground. But mechanics soon discovered that grounding a heat exchanger to "collect" stray current merely accelerated the damage to the heat exchanger. What they really needed, they found, was a way to draw the stray voltage away from the heat exchanger, similar to what boaters do when they install "sacrificial" zinc anodes that collect and dissipate stray electrical current before it chews up a boat's engine, propeller, or metal hull.

It isn't practical, nor is it advisable, to install sacrificial zincs to protect an automotive cooling system, though several rad shop owners with a knowledge of boating have inquired about the idea. Instead, the proper repair is to locate and eliminate the source of the stray current.

In a handful of cas
 
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Old 09-10-03, 06:24 AM
Joe_F
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Rick:

What is it you're trying to accomplish?
 
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Old 09-10-03, 10:13 AM
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Hi Joe. I thought this post might be a little confusing. I am trying to determine if electrolisis might be at the root of my cooling system staying full of rust as if it is being run without anti-freeze.

I intend to clean some cast iron stove parts with this process and am wondering if I clean my radiator the same way, if it is all metal.

If anyone is interested in reading about this process to clean metal, the addy is below.

http://users.eastlink.ca/~pspencer/n...ctrolysis.html

P.S. Sorry about the copy and paste of the article. I should have just posted the addy.
 
  #4  
Old 09-10-03, 10:24 AM
Joe_F
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If you maintain a cooling system properly, there's no need to do anything but flush the coolant every year and change the wear out parts (hoses, belts, etc).

If the radiator gets clogged, best to have it professionally boiled out by a shop. At this time, any and all leaks will be found.

Regarding flushing a COOLING system, use a Prestone Flush 'N' Fill kit. Best bet as it reverse flushes the system.

Hope that helps.
 
  #5  
Old 09-10-03, 12:29 PM
boman's Avatar
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been there, done that. Still had rust in the coolant. Thats why I thought electrolosis may have played a part.
Tx for the reply
 
  #6  
Old 09-10-03, 12:51 PM
Joe_F
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How often are you changing the coolant? If not yearly, it's too long.
 
  #7  
Old 09-10-03, 07:15 PM
boman's Avatar
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Yearly....I think.

I am pretty sure I have had vehicles that were not changed exactly yearly and I did not have this problem. I realy think I have backflushed this one more than once in the same year and still had the same problem. even changed the thermostat. If I can, I will see if I am getting any reading through the coolant. Then I will know.
 
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Old 09-10-03, 10:50 PM
mike from nj
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i've seen a few cars/trucks where the coolant was left in way too long, the green antifreeze resembled mud!

unfortunately, once it gets this far, it is very hard to get out. the rust settles into the bottom of the engine block and likes to stay there, i've tried chemical flushes and a hose into the open thermostat hole---no luck.

when it gets this far, the only way i know is to either take the cylinder heads off or take out all the freeze plugs and spray it out with a garden hose for a while until all that settled rust comes out.

i'll sometimes change my anti-freeze every 3-4 years, never had a problem. on customer's cars, with severe rusting, even with the block drain plugs removed, i never get all the rust out. just mix up the new antifreeze 50/50 with water and send them on their way, it won't freeze, it won't overheat and it cools the engine, what else do you need?

mix up a fresh batch, change it every year and keep an eye on the level, that's your 'short' option---short of taking it all apart.
 
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