Everything You Need To Know About Black Anodizing
What is Anodizing?
Before we can begin to answer the question “what is black anodizing?” we must understand what anodizing itself is.
Anodizing is the electrochemical process in which a metal surface is coated with a water-resistant oxide layer. Anodizing can be performed on a range of metals, such as magnesium and titanium, but is best suited for aluminum. There are three main types of anodizing: Type I-Chromic Acid Anodize, Type II-Sulfuric Acid Anodize, and Type III Hard Anodize.
Type I-Chromic Acid Anodize:
While chromic acid provides the thinnest anodizing coat of the three types, the metal is equally protected from corrosion when adequately sealed. However, chromic acid anodize absorbs less color when dyed and is not recommended for aesthetic purposes. It can be dyed black, but to do so, the temperature of the chromic acid must be increased.
As a result of health and worker safety concerns, environmental concerns, and costs linked to the continued use of chromium, boric-sulfuric acid anodize can be used as an alternative to chromic acid anodize.
Type II-Sulfuric Acid Anodize:
The most common method for anodizing, sulfuric acid, is especially beneficial in resisting abrasion. Sulfuric acid also has a porous nature meaning it absorbs dye well and allows for a large variety of colors.
Type III Hard Anodize (Hardcoat):
Hardcoat anodize is considerably thicker and denser than the more commonly used sulfuric anodize. Due to its durable coating, hardcoat anodize is preferred when a metal is exposed to corrosive or strenuous environments. It can also be used when advanced electrical insulation is needed.
What is Black Anodizing?
Black Anodizing is the technique used to dye the surface of a metal black. During the anodizing process, before the sealing stage, the oxidized surface of the metal has the ability to be dyed.
What is The Purpose of Anodizing?
There are a range of reasons one might choose to anodize a metal, including corrosion resistance, wear resistance, heat dissipation, surface lubricity, non-conductive properties, adhesion, and aesthetics. Anodizing is a porous structure, meaning it is also beneficial for absorbing colored dye.
How Long Does it Take to Black Anodize?
Anodizers usually require between a few days and a few weeks to plan, process, and invoice your request, but the wait time is seldom over six weeks.
How Much Does It Cost to Black Anodize Metal?
Various factors affect the cost of anodizing, including the dimensions of the metal, the anodizing types, the coating thickness, and any extra services you may require. It is best to speak to your anodizer directly for specific prices on your request.
Does Black Anodized Fade, Rust, or Scratch?
Anodized metals are made to resist corrosion better than natural, unfinished metal. However, fading and discoloration will occur over time. The two factors commonly understood to contribute to fading are the anodic coating dyes used and the sealing of the dyed anodize.
Organic anodic dyes are rated from 1-10 on their ability to combat exposure to elements such as lights (specifically UV), chemicals, and heat. Black dyes are designed to provide substantial protection to all three elements, whereas colors such as turquoise or pink may be more susceptible to fading. A way to prevent fading is to replace inorganic dies used with organic dyes.
In addition to dye type, sealing is a crucial aspect of the longevity of anodized metals. If the sealing process is skipped or performed poorly, the anodized metal will fade quickly.
The likelihood of a metal rusting, depends on the type of metal that was anodized. Aluminum, for example, does not rust. However, it can corrode when exposed to certain substances such as salt or acid rain. Steel, while known for its ability to resist corrosion, can rust when in contact with corrosive environments such as chloride and excessive exposure to high temperatures.
No metal is completely sheltered from scratches, but typically the thicker the anodize, the better protected the metal will be.
How To Clean Black Anodized Metal?
When cleaning an anodized metal, you will want to use an abrasive cleaning method, such as a rough sponge, with a gentle soap, such as a mild dishwashing liquid. Alkaline and acidic cleaners should be avoided, as they have the potential to ruin your metal’s finish. Solvents also have the ability to taint the finish and should be used vigilantly.
Remember to test out your cleaning method on a small area before diving into the process headfirst.
Is Black Anodizing Environmentally Friendly?
Yes! Black anodizing does not generate any toxic waste or use heavy metals! It also adheres to environmental and safety regulations set by the FDA, ELV, USDA, WEEE, and RoHS.
The High Quality Alternative – Acktar Black
Where the optical performance of the coating is a factor Acktar black coatings deliver superior performance over a wide range of wave lengths.
Additionally – unlike anodization – Acktar processes are completely environmentally clean and do not utilize acids or other environmentally harmful materials.