electronic anti-rust device

[forestraven]

I live in an area of Canada where they use a lot of salt on the road to remove snow. A device was introduced first by Toyota, then Canadian Tire that changes the electrical charge in the metal. As I understand there are a large number of electrons held in weak bonds that give steel a positive charge which interacts with the negative charge in salt to speed up rusting. The anti rust device creates a neutral charge in the metal thus reducing, or eliminate rust. I am not sure that my explenation is correct, but I had this device in my last car, a Toyota Camry which had no visible rust on it when I traded it in for another car when the transmission went. My question is if this system might also work for OWB? Wouldn't it be great if a $250. piece of equipment would reduce corrosion and rust in the boilers of our outside stoves extending the lifetime of these stoves. Does anyone know the chemistry behind these devices, and do you think they would work for OWB? I know that they are used by ships, which is where the idea cam from apparently. J

 

[forestraven]

I should add that I had the car fourteen years. I kept it because it did not rust out like our cars up here do, even when they are undercoated. The Camry had been undercoated, but it also had this device installed when it was new, before it was drven on our winter roads. Jamie

 

[jimbom]

I have used cathodic protection on various metal structures in the ocean and buried/touching the earth.
http://en.wikipedia.org/wiki/Cathodic_protection

I don't have an OWB, but I take from your post it they corrode if the metal is in contact with the ground. There are a lot of design guides out there, but this is kind of a black art. The best chance for success might be for you to talk to the local water company, pipeline, power plant, highway department or fuel farm. Those people would know what works in your soil and climate. If you are close to the ocean, you can find someone that operates anything steel in the ocean.

If you can find a sacrificial anode such as a lump of magnesium, electrically connect that to your steel and bury the anode in moist soil. Use copper wire and exothermic welds. There is a lot more to it, but that should do the trick. Five pounds will last a long time on a small stove. If you want to see if it is working, put in a test box and check it after it has had a few months to get going. You should be able to measure a few milli-amps flowing between the stove and the anode. All depends on your local soil conditions.

The USDA soils maps identify soils that cause corrosion. You can search right down to your property and read all about it.

 

[PassionForFire&Water]

I have used cathodic protection on various metal structures in the ocean and buried/touching the earth.
http://en.wiki.org/wiki/Cathodic_protection

I don't have an OWB, but I take from your post it they corrode if the metal is in contact with the ground. There are a lot of design guides out there, but this is kind of a black art. The best chance for success might be for you to talk to the local water company, pipeline, power plant, highway department or fuel farm. Those people would know what works in your soil and climate. If you are close to the ocean, you can find someone that operates anything steel in the ocean.

If you can find a sacrificial anode such as a lump of magnesium, electrically connect that to your steel and bury the anode in moist soil. Use copper wire and exothermic welds. There is a lot more to it, but that should do the trick. Five pounds will last a long time on a small stove. If you want to see if it is working, put in a test box and check it after it has had a few months to get going. You should be able to measure a few milli-amps flowing between the stove and the anode. All depends on your local soil conditions.

The USDA soils maps identify soils that cause corrosion. You can search right down to your property and read all about it.

This way of protection against corrosion (galvanic) is know under; Cathodic protection by means of a "sacrificial anode".
You sacrifies the zinc, to spare the steel.
Each domestic electric hot water heater has one these days.
It gives your water heater protection for as long as ..... there is zinc or something to sacrify.

 

[Bad Wolf]

Actually I think he is talking about an "impressed current" system. Which is one better than a straight sacrificial anode. A sacrificial anode just give the system something thats higher on the corrosion zinc corrodes more than steel. There must be a an electrical path both ways which is why is works so well in salt water. Basically its a battery. (remember your copper/zinc battery is science class?)
An impressed current applies a small charge to the part to make the electrons move in the right direction. Used widely on underground tanks and pipe lines.

Try http://www.corrosion-doctors.org/CP/Impressed.htm

 

[forestraven]

Great information, but after reading the information on the sites it is clear that one needs to get it right. It clearly is something that should be used on the boilers where:
-dissimilar metals are often used setting up galvanic charges
-oxidization occurs due to have oxygen absorbed in open systems
-the effects of certain types of soils on metal structures