I've had this Maine 'buoy bell' wind chime for about eight years now. It has the haunting melancholy sound of a bell buoy at sea being tossed by wind and waves. It is made of COR-TEN steel which is designed to rust on the surface to create a protective barrier against further rusting. It came painted black on the outside and was supposed to develop this rich rust patina naturally over time.
Seeing it was taking so long, I decided to take things into my own hands and, ah, "help" mother nature along and accelerate the process. I searched the net and found mostly dangerous methods to induce rust on steel using highly caustic or acidic chemical solutions. However I finally did find a simple safe method, using on-hand household chemicals, buried deep within a thread on the subject at a metalworking forum.
I got spectacular results which have not only withstood the wind and rain of the southwest but have actually improved with the help of mother nature. Over time, the oxygen combines with the metal forming new compounds collectively called rust. The best-known of these reactions involve oxygen, hence the name "oxidation". The terms "rust" and "rusting" only mean oxidation of iron and its resulting products. Many other oxidation reactions exist which do not involve iron or produce rust. But only iron or alloys that contain iron can rust.
However, other metals can corrode in similar ways. It occurs when iron combines with the oxygen in the air causing it to corrode. Rust is the orange-brown discoloration that builds up on metal. Rust can affect iron and its alloys, including steel.
Whenever you have iron, water and oxygen together, you get rust. Although iron and steel structures seem solid to the eye, water molecules are able to penetrate microscopic gaps in the metal. If salt is present, for example in seawater, the corrosion will be more rapid. Exposure to sulfur dioxide and carbon dioxide will also hasten the corrosive process.
The fast and DIY way to rust metal on purpose is to make a mixture in a spray bottle of white vinegar, hydrogen peroxide, and salt. Spray the mixture onto the metal surface several times, letting it dry between coats and your metal will take on a rusty patina almost instantly. Rust is formed when oxygen comes into sustained contact with iron in a process called oxidation.
Oxygen is delivered to the metal from water, either from liquid water or water vapor. The free oxygen bonds with the dissolved iron to form iron oxide or rust. Oxidation catalysts, such as saltwater and air, acids and acid rain, soils, and airborne sulfur compounds, will accelerate rust formation.
Rust formation is also encouraged by architectural crevices that trap liquids. Once rust forms, its porous surface will trap additional liquids and lead to further corrosion. This is accomplished through hot-dip galvanizing or electroplating. The iron or steel object is coated in a thin layer of zinc.
This stops oxygen and water reaching the metal underneath but the zinc also acts as a sacrificial metal. Zinc is more reactive than iron, so it oxidizes in preference to the iron object. The zinc oxide layer prevents the formation of iron oxide, thus eliminating the possibility of rust forming. Pour two cups of hydrogen peroxide, four tablespoons of white vinegar, and one-and-a-half teaspoons of table salt into a plastic spray bottle. Once the salt has dissolved, spray the solution over the object to coat it partially or completely, depending on the desired effect.
The peroxide should begin to bubble on contact with the metal, and rust will start forming immediately. Let the object air-dry in the sun for another five minutes or longer, depending on the size of the object. Degrease the stripped metal with a commercial degreaser to remove grime, dirt or remnants of finish that will prevent the chemical reaction that causes rust.
Wear protective goggles and gloves every time you handle chemicals during the rust patina process. Do not handle a degreased piece of metal with your bare hands, to avoid any skin oil residue, which repels the rusting solution. When iron is in contact with water and oxygen, it rusts. If salt is present, for example in seawater or salt spray, the iron tends to rust more quickly, as a result of chemical reactions. Iron metal is relatively unaffected by pure water or by dry oxygen. As with other metals, like aluminium, a tightly adhering oxide coating, a passivation layer, protects the bulk iron from further oxidation.
The conversion of the passivating ferrous oxide layer to rust results from the combined action of two agents, usually oxygen and water. Given sufficient time, any iron mass, in the presence of water and oxygen, could eventually convert entirely to rust. Surface rust is commonly flaky and friable, and provides no passivational protection to the underlying iron, unlike the formation of patina on copper surfaces. Rusting is the common term for corrosion of elemental iron and its alloys such as steel. Many other metals undergo similar corrosion, but the resulting oxides are not commonly called "rust". Corten steel is a steel with added phosphorus, copper, chromium and nickel-molybdenum.
These alloys increase the corten steel's resistance to atmospheric corrosion by creating a protective patina on the surface. This patina usually forms in 1 to 3 years, depending on the environmental conditions and the alternation of wet and dry periods that help the patina adhere. Due to the presence of phosphorus, this protective layer regenerates continuously on the surface and forms a barrier against moisture, oxygen and pollution. Working in a well ventilated area, pour the peroxide into the spray bottle. Spray the tin or iron with peroxide, misting generously. Rusting should begin almost immediately, and is sort of fun to watch.
Allow items to dry completely, and then rub to remove salt. Different effects can be achieved using more or less salt. I also achieved some nice rusting by letting the items dry, and then remisting them with peroxide to start the process all over again.
Rinsing the rusted item in cold water removes some of the rust, and gives a smoother surface. This is definitely a technique to experiment with fully before you plunge in with a big piece. First, you'll need to create a rusting solution by combining 16oz hydrogen peroxide, 2oz white vinegar, and ½ tablespoon of salt. If possible, mix this solution in the spray bottle with some of the leftover white vinegar.
Shake it up so that everything mixes well, and then start spraying down your object. First, you'll need to create a rusting solution by combining 16oz hydrogen peroxide, 2oz white vinegar, and ½ tablespoon of salt. In some applications, particulate residue from a plain steel or iron workpiece may be transferred onto the surface of a stainless steel part or basket. These plain iron or steel particles can disrupt the protective oxide layer of a stainless steel workpiece—ruining its corrosion resistance so that it starts to rust.
When metal parts are properly stored with VCI Packaging products, VCIs activate and fill up the vapor space inside the packaging. The VCI ions form a shield of protection on the surface of metal that displaces moisture and eradicates rust. VCI Packaging safely prevents corrosion on protected metals without the need for messy grease, oils, protective coatings or other time-consuming methods.
The rust process is exactly the same for corten steel, except that it doesn't regenerate itself. The addition of the alloys mentioned above produces more stable rust that adheres better. The succession of wet and dry periods acting on corten steel thus produces corrosion on the surface until a layer of resistant and protective metal oxide forms. When this layer matures, it no longer gets any marks and makes the steel less permeable. After a few days, the solution should be ready to use. The copper wire will still be there, but you should see that the acid has chewed into it a bit.
Once the acid has got some copper in it, the greenish acid/copper mixture will deposit a bright layer of copper on a piece of clean steel that you dip into it. The coating is extremely unstable and will soon be replaced by rust. You don't really want to use it like that anyway, as it will go a lot farther and be a lot less dangerous if you dilute it with water. You may have to play with the ratio, but somewhere between 20/1 to 100/1 of water to acid/copper solution should work well.
If you apply it with a spray bottle, just realize that it won't be long for the world. The acid will eat the spring in the bottle, so it will quit working after a few days. The only thing I've found that really works longer is a little plastic hand-pump Hudson sprayer that has no metal in it.
Believe it or not, you can pickle metal with the same ingredient that is used to pickle cucumbers. Place your object where you can spray it from all sides, away from anything you don't want to get sprayed, including people, pets, and other objects. Not too much, just enough to cover the object several times.
Placing the object in direct sunlight will speed drying. The acid in the vinegar will etch the surface of the metal so chemicals can penetrate. If you skip this step and proceed with the next step or don't like the results of the next step, just come back to this step and spray again with vinegar. The acid in the vinegar will dissolve most of the rust. You will be using an acid, vinegar, and an oxidizer, hydrogen peroxide, so do wear the safety goggles and gloves.
It is mildly corrosive and will rust anything made of iron or steel. Do this outdoors preferably in a place sheltered from the wind and away from people or pets. Do use common sense and follow common safety practices.
Do not spray chemicals at anything other than the object you are trying to rust. Obviously don't spray it anywhere near people or animals. If you do get some in your eyes, go and rinse your eyes with cold or lukewarm water immediately. Although the chemicals used are relatively safe, common sense should prevail.
If you do not possess common sense, please don't try this at home, or anywhere else for that matter. Finally, maintenance will have an effect on the metals ability to resist rust. The chromium in stainless steel reacts with oxygen in the air to produce a protective chromium oxide layer across the surface. Although very thin, this layer is what protects the metal from corrosion.
How To Make Corten Steel Rust Faster Some chemical reactions in which bacteria participate are harmful rather than helpful to industry. Bacteria are major agents of metal corrosion through the formation of rust, especially on metals containing iron. During the early stages of rust formation, hydrogen is produced, and it acts to slow the rusting process. However, certain bacteria use the hydrogen as a nutrient with the result that they greatly speed up rust formation. For this next step, you're going to fill each spray bottle with a designated solution. Add two cups of hydrogen peroxide, four tablespoons of white vinegar, and one tablespoon of salt to the second spray bottle.
Many spray bottles have measurement markers that eliminate the need for a measuring cup. You may use a funnel to transfer all three ingredients into the spray bottle. Once the ingredients are fully incorporated, cap the spray bottle. Use a Sharpie or small piece of painter's tape to mark the bottle. Shake the bottle until all of the ingredients are mixed and the salt is fully dissolved.
Set the degreased object outdoors or in a well-ventilated area on a piece of cardboard. Work in an area where you can spray rusting solution without affecting nearby surfaces. Spray your metal object with plain white vinegar, soaking the surface and letting it dry before reapplying.
The acidic vinegar lightly etches the metal surface so the piece will rust faster. The term stainless steel is a reference to the alloy's tendency to resist rust under normal conditions. Paints will also create a protective layer over metal objects and prevent moisture from reaching them. Of course, no barrier can completely stop moisture from getting through, but painting can be a simple and easy way to slow down rust. If you already want to paint the object a different color or get a different finish, this is an ideal solution. Dry coating rust prevention products such as ARMOR's Dry Coat Rust Preventative can be applied via spray, dip or wash.
Once they dry, the protective barrier is in place. The metal won't look or feel any different, so its applications remain the same. Dry coatings can also be used in combination with other ways to prevent rust. For example, you might use a dry coating over a painted or powder coated object to increase the level of protection.
