What is a Cathodic Protection
#1
02-07-01, 08:56 PM
What is a Cathodic Protection, I just dont understand what the plumber is talking about with my drinkable water.
#2
02-07-01, 09:10 PM
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WHAT IS CATHODIC PROTECTION?
According to my Funk & Wagnalls, “cathodic” is a derivative of the word “cathode” which means “The negatively charged electrode that receives cations during electrolysis.” The definition of “anode” in the same dictionary is “The positive electrode toward which anions migrate in an electrolytic cell.” “Corrode” means “To eat away or destroy gradually as by chemical action.”
Quite simply put, corrosion is the deterioration of different materials caused by a chemical reaction with the environment. The field of cathodic protection basically refers to corrosion in structures such as pipelines, storage tanks, water towers, UST’s and various other metal structures. But many different materials can corrode such as wood, rubber and even plastic. When artifacts or treasures are exhumed, whether it is from land or water, they are immediately susceptible to more rapid corrosion from the new environment they are exposed to. Technology today has devised ways to try to prevent (a nice thought but not always possible) or limit or at least delay corrosion. That is what cathodic protection is. Probably for as long as man has been using metal implements, he has seen them corroding gradually and he has strived to devise ways to protect them so they would not deteriorate. From this desire and necessity has sprung a very complex field called cathodic protection. There are engineers and scientists who devote their lives to this endeavor. It is an extremely complicated field. It is a lot more than taking a potential and achieving a reading more negative than -0.850!
This best I can see forw what I found on the web, is it must have something to do with the water heater anode rod.
Was you and him talking about a water heater?
According to my Funk & Wagnalls, “cathodic” is a derivative of the word “cathode” which means “The negatively charged electrode that receives cations during electrolysis.” The definition of “anode” in the same dictionary is “The positive electrode toward which anions migrate in an electrolytic cell.” “Corrode” means “To eat away or destroy gradually as by chemical action.”
Quite simply put, corrosion is the deterioration of different materials caused by a chemical reaction with the environment. The field of cathodic protection basically refers to corrosion in structures such as pipelines, storage tanks, water towers, UST’s and various other metal structures. But many different materials can corrode such as wood, rubber and even plastic. When artifacts or treasures are exhumed, whether it is from land or water, they are immediately susceptible to more rapid corrosion from the new environment they are exposed to. Technology today has devised ways to try to prevent (a nice thought but not always possible) or limit or at least delay corrosion. That is what cathodic protection is. Probably for as long as man has been using metal implements, he has seen them corroding gradually and he has strived to devise ways to protect them so they would not deteriorate. From this desire and necessity has sprung a very complex field called cathodic protection. There are engineers and scientists who devote their lives to this endeavor. It is an extremely complicated field. It is a lot more than taking a potential and achieving a reading more negative than -0.850!
This best I can see forw what I found on the web, is it must have something to do with the water heater anode rod.
Was you and him talking about a water heater?
#5
02-08-01, 12:24 AM
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My guess about what your plumber means by cathodic protection for a water tank would be very similar to such protection for boat motors that all have sacrificial zincs attached to the lower units.
The electrolysis that corrodes metals - when mixing water and metal - is diverted to the zinc (the cathodic protection), which protects the other metal of the lower units.
Same-Same with the anode rods in water heaters.
He probably has something like that in mind.
That stuff is way beyond me, but it must work.
Of course, I believe in electricity, too, but don't ask me how THAT works either. LOL.
The electrolysis that corrodes metals - when mixing water and metal - is diverted to the zinc (the cathodic protection), which protects the other metal of the lower units.
Same-Same with the anode rods in water heaters.
He probably has something like that in mind.
That stuff is way beyond me, but it must work.
Of course, I believe in electricity, too, but don't ask me how THAT works either. LOL.
#6
02-08-01, 09:01 AM
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Both Plumber 2000 and Old Guy, are mostly correct. From an engineer's perspective, cathodic protection is an electrochemical method of corrosion control primarily used for corrosion protection of carbon steel in underground structures (pipes and tanks) and to protect ship hulls, off-shore structures, and water tanks. The idea is to make the equipment you are trying to protect (from corrosion), the cathode inthe electrolyte involved. The most common method of doing this is to use a "sacrificial anode", like Old Guy referred to on boat motors, and PB2000 referred to in water heaters. Sacrificial anodes are usually made of zinc, magnesium or aluminum, and must be in electrical contact with the metal to be protected. For underground pipeline protection, the anodes are usually buried in the ground. However, for ships hulls, water tanks, etc. the sacrificial anode is connected directly to the surface of the equipment you want to protect.
The other type of cathodic protection is the "impressed emf" method, which a direct current is appied to the system.
Now to your question:
"How would he apply Cathodic Protection to an already made product?"
To apply cathodic protection to your water tank, will require directly attaching a sacrificial anode, usually zinc or magnesium for water tanks. The success of the cathodic protection depends and a good electical contact between the cathode (water tank) and the sacrificial anode.
The other type of cathodic protection is the "impressed emf" method, which a direct current is appied to the system.
Now to your question:
"How would he apply Cathodic Protection to an already made product?"
To apply cathodic protection to your water tank, will require directly attaching a sacrificial anode, usually zinc or magnesium for water tanks. The success of the cathodic protection depends and a good electical contact between the cathode (water tank) and the sacrificial anode.
