Zum Hauptinhalt springen Zur Suche springen Zur Hauptnavigation springen

Vitreous enamel coating applications

Vitreous enamel (also known as porcelain enamel) is a glass-like, inorganic coating created by firing fused powdered glass at very high temperatures. The result is a durable surface with excellent resistance to corrosion, chemicals, and high temperature changes. It is also highly scratch-resistant and non-porous, making finished parts easy to clean. These properties make vitreous enamel an ideal coating solution for domestic, sanitary, and decorative applications.

Porcelain enamel has been used worldwide for decades, from traditional manual liquid coating processes to fully automated, engineered powder systems. Due to the specific characteristics of the material, enamel application requires specialized equipment for both powder and liquid processes, for example specially engineered nozzle geometries. The special requirements clearly set enamel systems apart as a distinct market niche.

WAGNER has installed more than 200 automatic enamel coating lines worldwide. As a strategic partner across multiple application fields, we offer a broad portfolio, technical expertise and global service support for enamel applications. Wagner S.p.A., based in Italy, serves as the special center of excellence for enamel technologies, featuring a dedicated laboratory for both powder and liquid coating applications.

Your contact

Marco Ghirimoldi

  • Business Development Domestic Appliances
  • +39 3355745088

    Selection of application areas for enamel coating

    Are you looking for a liquid and/or powder enamel solution for your workpiece? We are happy to support you!

    >>> Send us your request
    • Proven application components (guns, connection and lances), based on over 40 years of enamelling experience
    • Application technologies: Powder, liquid and flow coating
    • Combination of 3-axis and 6-axis robots for precise application on complex geometries
    • Controlled enamel temperature and humidity to ensure stable quality throughout the entire production cycle
    • Application technologies: Powder, liquid and electrostatic liquid coating
    • Efficient enamel recycling technology using gravity and air transport to reduce material consumption and running costs
    • Continuous improvements in application performance to lower consumption and spare part costs
    • Application technologies: Powder, liquid and electrostatic liquid coating
    • Customized solutions for semi-automatic or fully automatic applications
    • Combination of 3-axis and 6-axis robots for precise application on complex geometries
    • Application technologies: Powder, liquid coating
    • Combination of 3-axis and 6-axis robots for precise application on complex geometries
    • Dedicated guns with recirculation systems and components, based on over 40 years of enamelling experience
    • Application technologies: Powder, liquid and electrostatic liquid coating
    • Robot solutions for precise application on complex geometries
    • Dedicated guns with tungsten carbide components to enhance productivity
    • Turnkey solutions: Spraypacks with customized pressure tanks made of stainless steel and manual guns
    • Application technologies: Liquid and electrostatic liquid coating
    • Robot solutions for precise application on complex geometries
    • Dedicated guns with tungsten carbide components to enhance productivity
    • Highly reliable, automatic color change systems, controlled by PLC
    • Application technologies: Liquid and electrostatic liquid coating
    • Tailored solutions designed to meet individual customer requirements and boost productivity through reliable, high‑performance equipment
    • Dedicated technical office and product management team providing customized engineering systems
    • Application technologies: Powder, liquid and electrostatic liquid coating

    Coating methods with enamel

    Enamel coatings are available for both industrial powder and liquid application systems. Depending on the substrate, the workpiece geometry and coating requirements, either a powder or liquid engineered system is recommended.

    Step-by-step: Liquid enamel coating

    The coating of liquid spray enamel engineered systems work similarly to traditional liquid coating ones, the equipment being the main difference. Most commonly metal or glass, is coated with a vitreous enamel layer that provides long-lasting protection.

    Typically, four steps are required:

    The substrate or workpiece is pre-treated to ensure optimal adhesion of the liquid enamel. This includes mechanical processes such as sandblasting or chemical treatments using alkaline and acid solutions, followed by thorough rinsing.

    The ready-to-use (RTU) enamel powder is mixed with water based on a specific water to powder ratio given by the material supplier. After 24 hours, both the specific gravity, the pickup weight and draining time are checked out in order to verify the enamel physical properties and adherence onto the substrate. 

    The cleaned workpiece substrate is subsequently coated using either a conventional low-pressure spraying system, consisting of a pressure tank connected to a manual or automatic spray gun, or an electrostatic spraying system in which the enamel slurry is applied electrostatically and transferred towards a grounded workpiece. 

    After coating, the workpiece is allowed to dry before being transferred to a firing furnace, where the enamel is fused to the steel substrate at high temperature (typically 800–900 °C). This produces a dense, glass-like protective layer with excellent adhesion, chemical resistance, and durability. 

    Applications requiring both ground and top coatings follow an extended process sequence, in which the ground-coated and fired substrate undergoes a second coating application, followed by an additional drying stage and a subsequent firing cycle. 

    Step-by-step: Powder enamel coating

    In powder enamel coating, a carrier material, most commonly metal or glass, is coated with a vitreous enamel layer that provides long-lasting protection.

    Typically, three steps are required:

    The substrate or workpiece is pre-treated to ensure optimal adhesion of the powder enamel. This includes mechanical processes such as sandblasting or chemical treatments using alkaline and acid solutions, followed by thorough rinsing.

    The enamel powder is applied using electrostatic principles. During the coating process, the powder particles are electrically charged and attracted to the grounded workpiece, where they adhere evenly to the surface.

    After coating, the workpiece is allowed to dry before being transferred to a firing furnace, where the enamel is fused to the steel substrate at high temperature (typically 500–900 °C). This produces a dense, glass-like protective layer with excellent adhesion, chemical resistance, and durability. 

    You might also be interested in

    Receive info material

    Trainings & workshops

    Learn more

    Customer references

    Learn more

    Contact form

    Send us an inquiry using the form below and we will contact you as soon as possible.

    FAQ about enamel coating

    Enamel coating offers a unique combination of physical, chemical, mechanical, and ecological benefits.

    Physical properties 

    • Non-combustible and fire-safe (does not burn or release toxic gases)
    • High temperature resistance (stable under direct flame and extreme heat)
    • Excellent resistance to thermal shock (unaffected by sudden temperature changes)
    • Impermeable to water and moisture
    • Dielectric properties (high electrical resistance)
    • Long-term color stability (resistant to visible and UV radiation)

    Chemical properties 

    • Excellent resistance to corrosion and weathering
    • Resistant to chemicals and aggressive substances

    Mechanical properties 

    • High scratch resistance
    • Excellent abrasion resistance
    • Good impact resistance 

    Ecological properties 

    • Inhibits bacterial growth due to its smooth surface and alkaline pH
    • Fully recyclable (does not interfere with the recycling of the base material)
    • Safe for use and suitable for contact with food and drinking water

    Vitreous enamel is an inorganic, glass-based material made from a mixture of minerals such as quartz sand, feldspar, borax, soda, and fluorspar. The exact composition varies depending on the application and required coating properties.

    The choice between liquid and powder enamel coating depends on several factors. Workpiece geometry is a key criterion: complex shapes, deep recesses, or sharp corners are often difficult to coat with powder, as the material cannot penetrate these areas effectively. Production volume also plays an important role. For small batches and frequent color changes, liquid enamel application is typically more efficient than powder coating.

    A combined powder and liquid enamel process is recommended when high coating thickness is required or when a dedicated ground coat must be applied before different finishing colors.

    Classic powder coatings are organic materials, while powder enamel is an inorganic, glass-based coating. Due to its material properties, powder enamel is more challenging to charge electrostatically and requires more precise process control, making the application technically more demanding than conventional powder coating.

    In liquid enamel coating, two main layers are used: the base coat and the top coat. The base coat, also referred to as ground coat or primer, ensures reliable adhesion between the substrate and the enamel system. The top coat forms the visible surface and provides the final appearance as well as resistance to mechanical, chemical, and environmental influences.

    The firing time depends on part size, enamel thickness, and furnace capacity. Typically, liquid enamel is fired for around 10 to 15 minutes at temperatures between 820 and 860 °C.

    Liquid enamel coating is typically a low-pressure application. This allows gentle material handling and precise control of the enamel layer, which is essential for achieving uniform coating quality.

    Liquid enamel glazes can be oil-based or water-based, with water-based systems being the most widely used today.