Metal is the primary substrate in which we may want to instigate rust to create a patina effect. Rusty metal is the foundation for many automotive fauxtina (man-made patina) projects, and the aesthetic foundation of the entire “Rat-Rod” style of custom car building in the automotive aftermarket. The act of taking a decades-worn vehicle and enhancing the deteriorated metal and paint has become a genre of custom car creation, and it bears acknowledgment and legitimate praise in the industry for expanding the way cars and customizing can be appreciated.
These processes take a lot of time in nature. Thick iron beams will remain strong for hundreds of years while steadily rusting. Copper or bronze will slowly change outer coloration and develop beautiful patina over the years. We simply don’t have another 50 or 60 years to let vehicles ferment and degrade, so we must come up with techniques to accelerate time or fool the eye to give the appearance that we have. A simpler, more natural, and more passive approach to accelerated rusting simply involves exposing the metal to chemicals and letting time and chemistry take its toll, although not the decades-long time frames that nature demands.
Basic Chemistry
Oxidation is not always rust colored on iron. In most cases, the oxidation process will deteriorate completely through the metal, the top layer will flake off and expose underlying iron, and it will eventually disintegrate completely. Copper oxidation (such as the green patina on the Statue of Liberty) bonds to the base metal and forms a protective layer on top, creating a chemical seal against the outside atmosphere and slowing or stopping the deterioration process. You can speed up the process of rusting with acids and salts to create the appearance of natural exposure.
Adding an acid to metal produces hydrogen gas, which promotes faster oxidation. When you add a couple of tablespoons of salt to a cup of a mild acid, such as vinegar, you create a very corrosive solution that can then be sprayed onto bare metal products, such as fasteners and hinges. If you then have a container of ammonia sitting beside the coated parts, the fumes will affect the sprayed solution and set in motion a chemical reaction that will deteriorate the outside surfaces of these metals very quickly.
This Tech Tip is From the Full Book, HIGH PERFORMANCE AUTOMOTIVE COOLING SYSTEMS. For a comprehensive guide on this entire subject you can visit this link:
LEARN MORE ABOUT THIS BOOK HERE
SHARE THIS ARTICLE: Please feel free to share this post In Facebook Groups or any automotive Forums or blogs you read. You can use the social sharing buttons to the left, or copy and paste the website link:
https://www.musclecardiy.com/uncategorized/how-to-create-patina-on-metal/
Ventilation
Please take all precautions to maintain a well-ventilated area and to use appropriate safety equipment while mixing chemicals. While we show you how to mix certain simple chemicals together to gain an effect on metal, certain reactions could occur if care is not taken to be safe. Take the warning labels on these household items seriously! Have fun with this, but please stay safe. This will create the appearance that a particular part has been rusting for a very long time.
Accelerated Rusting
By using basic chemistry and common products, we can create a cool rusted surface that looks as if it has been rusting for years. Vinegar is a mild acid, ammonia is a common household cleaner, and table salt has obviously been around for millennia as a spice and flavor enhancement. Individually, they are benign compo- nents, but once we put chemistry to work, they work with and against each other to give us great rusty results!
To demonstrate how to create patina, we will apply some sim-ple household chemicals to a small piece of 20-gauge bare steel. Please be aware that even though these prod-ucts are available over the counter, mixing acids and corrosive elements can potentially cause harm or serious injury. Appropriate safety equipment is always necessary. Wear gloves, safety glasses, and protective cloth-ing in a well-ventilated area when practicing this method.
1 Our chemistry experiment involves very simple compo-nents: vinegar, ammonia, and simple table salt. You also need plastic mixing pails and a plastic spoon to ensure that no unexpected results occur. Our 20-gauge steel sample is cleaned but untreated and unsanded.
2 Add 12 ounces of distilled vinegar to the mixing cup. Vinegar is a mild acid, and in its distilled form, it is reduced to 5-percent acidity. This will normally pro- duce a nice patina if given enough time in a very safe manner, but we’re pushing the envelope in this case.
3 Wear gloves and safety glasses while pouring, just as a good practice. Bodyshop etiquette serves many purposes, one of which is obviously safety. Controlling your environment is another so you can safely track results and repeat them later.
4 Next, add 2 tablespoons of regular iodized table salt to the vinegar. This creates a much more aggressive solution. On a very small scale, adding the salt (sodium chloride) creates a mild hydrochloric acid that acts much more aggressively when it comes in contact with a metal surface.
5 Blend the salt and vinegar together thoroughly until you don’t see any salt in the bottom of the mixing bucket.
6 Using a brush, cloth, or sponge, completely wet the surface of the metal. This begins the chemical process of accelerated oxidation. You’ll probably notice an immediate effect of the metal “brightening” as it gets wet with the vinegar solution. This particular mix is a great way to clean up copper pennies and remove the patina from them as well.
7 Place the wet metal into a 1 gallon plastic bucket. It is now in a contained area where the sample can stay as wet as possible for as long as possible.
8 Add 2 ounces of ammonia to a smaller plastic cup. Ammonia is most commonly an active ingredient in household glass cleaners.
ContinUed 9 Set the small cup of ammonia in the 1 gallon bucket, making sure the chemicals and containers are separate! The fumes alone will create the chemis-try we’re looking for in a safe and controlled manner.
10 Ammonia mixed directly with or poured onto the vinegar solution will make a toxic gas called chloramine that can be danger-ous. There may already be a mix of odors present from the vinegar and ammonia. Make sure you’re in a well-ventilated area when doing this experiment or anything similar. Stay safe!
11 To speed the process, use cellophane to place a temporary lid on the large bucket. You do not want a fully air-tight seal, just a way to contain the fumes.
12 A wrap of masking tape will hold the plastic in place while still allowing air to enter or escape the bucket. Wear safety glasses (not shown) and gloves! This allows you to look over into the bucket to see the process happen without being exposed to any fumes.
13 After only 5 minutes, you can see a noticeable change in the metal. A nice film of rust is forming on the metal surface.
14 We allowed our sample to sit in the covered bucket overnight. You can see the amazing (and quite beautiful) layer of rust that has formed over the metal. A few hours and basic chemistry has taken the place of years of natural deterioration.
Bleach, Vinegar, and Steel
Metal responds differently to bleach and to vinegar. With the two effects in mind, you have a variety of surfaces and effects to play with in your creation of fauxtina. When you think about it, to be able to create the illusion of steel that has sat in the elements for decades in the space of a couple of hours or weeks is powerful! When you consider that a typical paint job takes weeks to complete, or even months and years for some DIY painters, a few weeks to create a great-looking patina on steel is not much time at all!
This Tech Tip is From the Full Book, HIGH PERFORMANCE AUTOMOTIVE COOLING SYSTEMS. For a comprehensive guide on this entire subject you can visit this link:
LEARN MORE ABOUT THIS BOOK HERE
SHARE THIS ARTICLE: Please feel free to share this post In Facebook Groups or any automotive Forums or blogs you read. You can use the social sharing buttons to the left, or copy and paste the website link:
https://www.musclecardiy.com/uncategorized/how-to-create-patina-on-metal/
To show the different effects that can be obtained, we did a bleach versus vinegar experiment. It was done with the metal panels inside, in conditioned air, and not exposed to the outdoor elements. The process takes weeks instead of hours, but the results are truly authentic and genuinely oxidized.
Wearing a rubber glove for protection, I wet my hand with vinegar. For safety and contamination purposes, we always use gloves to perform experiments like this.
Seconds after removing my hand, you can see the difference between the dry metal and the effect of the vinegar on the metal. A slight halo of rust is already forming.
I then placed my hand flat against the 22-gauge untreated steel panel. This produces a wet impression of my hand on the panel.
One month later, the effects of the vinegar are very clear. The acid has etched into the top layer of the metal panel and accelerated the oxidation process by quite a lot compared to the years it might usually take to create the same amount of corrosion.
We did the same process to a 22-gauge untreated steel panel using household bleach.
The bleach is much more aggressive, and it evaporates more slowly than the vinegar. A few minutes after contact, you can see the chemical reaction starting and the hand impression becoming very clear very fast!
Again, I placed my hand flat against the panel, leaving a clear handprint on the surface.
One month later, the panel is aggressively corroding and rusting at a much faster rate than with the vinegar. Bleach is a natural oxidizing agent, which means that it adds oxygen molecules to the chemical process, facilitating rust even faster when exposed to the hydrogen (moisture) that’s in the air and atmosphere that we breathe. Notice also that the rust extends past the handprint, which gives clues to the chemical process that affects the surrounding metal on a microscopic level, even outside the point of direct contact.
Written by Kevin Tetz and republished with permission of CarTech Inc
LEARN MORE ABOUT THIS BOOK!
If you liked this article you will love the full book!