Unlike paint which bonds to metal surfaces but remains a separate coating, anodization converts the surface to provide a durable, corrosion-resistant oxide finish that is both part of the metal itself but also different from it. The finish is achieved by applying an electric current while dipping parts in an acid bath — so any section that shouldn’t be treated needs a tough masking tape for anodizing that can withstand this process.
Hard, abrasion-resistant surfaces will not peel or crack.
Electrically insulates the underlying metal.
Avoids thickness of painting and plating processes.
Colour can be embedded for decorative purposes.
Creates a very thin coating of 0.05 to 0.2 mils (0.0001 cm to 0.0005 cm).
Has minimal impact on fatigue strength of components.
Coating offers excellent corrosion resistance.
This process involves a chromic acid bath and increasing the applied voltage by 5 - 7V per minute starting from about 5V and going up to 40V through specific steps throughout the process. This anodization process is common on precision machine components and metalworking components for the aerospace industry, including welded components and assemblies. The anodization layer can be dyed — though it is more difficult than with Type II — and this process can also be used as a pretreatment before painting.
Clear purple polyester backing allows for easy accurate positioning while resisting abrasion, tears, scratches and punctures.
Non-silicone rubber adhesive removes cleanly in one piece while providing sharp masking lines and without interfering with downstream painting processes.
Can speed up masking and de-masking process by up to 5 times while helping reduce labour time and associated costs by up to 60%.*
*3M internal data on file.
Can be done at room temperature with 10V to 20V.
Provides a harder finish than chromic acid anodization.
Inexpensive compared to other processes.
Although Type II anodization may use other acids, sulfuric acid is the most commonly used. Producing a layer 0.1 to 0.8 mils thick, Type II anodization is performed at room temperature using approximately 10 - 20V and provides a harder finish than Type I. Type II anodization is most commonly used for military-grade components, shells for computers and other electronics, hydraulic valve bodies and mechanical hardware.
Creates a “hardcoat” finish up to 2 mils thick (0.005 cm).
Provides electrical and thermal insulation properties.
Extremely resistant to wear and corrosion.
Similar to Type II anodization, Type III is most commonly done with sulfuric acid, although other acids, or even combinations of acids can be used. Type III anodization is more complicated than Type I or Type II, and requires very cold conditions and up to 90V. Type III anodization is most commonly used for internal engine parts, sliding parts, hinge mechanisms and blast shields.
Use electricity to deposit a layer of any desired metal on another substrate in order to change the surface properties or to build up part thickness. Your masking tape must withstand the immersive solution without leaking but should also remove easily and cleanly with no or minimal residue requiring further attention.
Use electrical attraction to apply free-flowing dry powder to a part which then passes through an oven that melts the powder to form an even paint surface. The masking tape must be able to prevent powder from reaching masked areas while withstanding the high oven heat without transferring to the part completely.