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Spotlight on deep cobalt blue pigment

Although smalt, a pigment made from deep cobalt blue glass has been known at least since the Middle Ages, the deep cobalt blue established in the nineteenth century was a greatly improved one.

The isolation of the deep cobalt blue color of smalt was discovered in the first half of the eighteenth century by the Swedish chemist Brandt. In 1777, Gahn and Wenzel found cobalt aluminate during research on cobalt compounds. Their discovery was made during experimentation with a soldering blowpipe. The color was not manufactured commercially until late in 1803 or 1804.

Deep cobalt blue was generally regarded as durable in the nineteenth century. It requires one hundred percent of oil to grind it as an oil paint otherwise its cool tone can turn greenish due to the yellowing of linseed oil. To avoid the yellowing, Laurie suggested that it be used as a glaze color or mixing it with white. It is totally stable in watercolor and fresco techniques.

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Metals Suitable for Enameling

Porcelain enamel is an ancient decorative, coloring technique which fuses finely powdered glass to metal. Using intense heat, the glass melts, flows, and then cools to harden into a smooth, durable, and decorative, colored surface.

What Metals Can I Use?

Almost any metal can be enameled, but the most common are copper, fine silver, and high karat gold. Metal clay is a perfect material to use for enameling. It’s easy to texture, shape and form and can be sintered with the same torch or kiln used for enameling.

Copper

Copper is a great sub surface when using opaque porcelain enamel. If the metal itself is not a feature of the final work, using an inexpensive material like copper reduces the cost of the project.

Many porcelain enamel suppliers carry milled copper, untextured shapes (also known as ‘blanks’) which are useful for practicing on.

However, when copper or copper bearing metals are heated an oxidized surface develops. This oxidation creates a barrier that prevents the porcelain enamel from fusing to the metal surface unless it’s been properly prepared. See below for cleaning options.

Fine Silver

Fine silver is brilliant and reflective under transparent colors. Because it doesn’t oxidize, it is easy to fire with a torch or kiln.

Gold

Lump gold metal clay is an expensive option but would provide a beautifully rich under layer to transparent enamels, especially those in the warmer color range. You can achieve the same luscious glow by first applying a foundation of clear porcelain enamel to a fired silver clay base, then add Keum Boo foil, and finally apply the porcelain enamel colors.

Gold is infinitely soluble into silver. With each successive firing, more gold will absorb into the silver until it disappears, negating any effect. If you are only firing on one or two layers of porcelain enamel you might be able to keum boo directly to silver, but if you are doing a deep porcelain enamel with multiple firings the keum boo gold would eventually completely absorb and disappear, which is why it’s advised to apply a coat of clear porcelain enamel first.

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Cobalt blue color palette sources identified in the production

The cobalt blue color palette enamel coating on 112 fragments or small objects of Qing Dynasty Chinese, 95 of underglaze blue and white and 17 overglaze enamelled porcelains.

The cobalt blue color palette enamel coating on both blue and white and polychrome objects were created with a cobalt pigment that was rich in manganese with lesser nickel and zinc. This suite of accessory elements is generally considered to be characteristic of local, Chinese, sources of pigments. However, the cobalt blue color palette enamels were very different. The cobalt pigment here has low levels of manganese and instead is rich in nickel, zinc, arsenic and bismuth. No Chinese source of cobalt with these characteristics is known, but they closely match the elements found in the contemporary cobalt source at Erzgebirge in Germany.

Textual evidence has been interpreted to suggest that some enamel pigment technologies were transferred from Europe to China, but this is the first analytical evidence to be found that an enamel pigment itself was imported. It is possible that this pigment was imported in the form of cobalt coloured glass, or smalt, which might account for its use in enamels, but not in an underglaze, where the colour might be susceptible to running.

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Enamel Powder Coating vs Spray Paint Stove Enamelling

Paint or powder, powder or stove enamel, powder vs spray paint, or powder coat vs air drying? Windridge Coatings is a commercial paint application company. In over 30 years we have applied heavy-duty corrosion protection paints, aesthetic auto paints, enamel powder coatings and stove enamel. We have a fairly good knowledge of all processes and have taken the commercial decision to specialise in enamel powder coating. Enamel powder coating has been the fastest growth area of painting for the last 25 years at the expense of other paint systems.

Enamel Powder Coating

Improvements in application techniques have meant small decorative items to heavy and large components are suitable for enamel powder coating. What was once the reserve for architectural and mass production is now available for garden gates and enamel powder coating motorbike frames.

Application equipment for enamel powder coating is more expensive than wet paint systems. The gun alone can cost £4500. The paint is purchased as a powder, hence the name. It is temporarily stuck to the metal with an electrostatic attraction. (In the same way as you rub a balloon on your jumper and watch it stick to a wall, the granules of powder stick to the work piece). The oven is more expensive than stove enamelling because it has to heat the component to a higher temperature, about 200 degrees Celsius.

Why is enamel powder coating better?

  • Powder coating done properly is tougher than stove enamelling and air drying paints. This means it will take more of punishment before chipping.
  • There are no solvents used during the application and so it is environmentally greener.
  • Requires factory processing making a better chance of the component being stripped and blasted, for better corrosion resistance and adhesion.
  • It produces a more waterproof barrier than liquid paint (for comparable thickness) and therefore offers better protection against corrosion.
  • To hide metal imperfections, a Powder coating finish can achieve in two coats, what stove enamelling requires in 15 or more coats.
  • Therefore the price is comparable, or even cheaper than stove enamelling.
  • Powder coating is more resistant to scratching and marking.
  • Good quality powder coatings are available in high gloss and have negligible orange peel.
  • Dirt is easily washed off.
  • Powder coating can be compounded, polished and waxed like any other paint.

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What is industrial enamel paint used for?

Industrial Enamels are for industrial use and may be used on properly prepared and properly primed interior or exterior surfaces of wood, metal, masonry, plaster, and composition board. Recommended for use on floors and machinery.

People also ask, what is industrial enamel paint?

Industrial enamel is a medium oil/alkyd all-purpose enamel. Designed for industrial enamelinterior and exterior use. For use on properly prepared. Steel, Concrete, Wood, Plaster, Previously.

what is the difference between paint and industrial enamel? The difference between paint and industrial enamel is same as that between a car and a Ford as industrial enamel is a type of paint. Paint is mostly acrylic, water based or oil based. It is the oil based paints that have traditionally been referred to as industrial enamel though today one can get water based or even latex based industrial enamels in the market.

Subsequently, question is, what is enamel paint used for?

Industrial enamel paint is paint that air-dries to a hard, usually glossy, finish, used for coating surfaces that are outdoors or otherwise subject to hard wear or variations in temperature; it should not be confused with decorated objects in “painted enamel”, where vitreous enamel is applied with brushes and fired in a kiln.

Can we use industrial enamel paint on wall?

Industrial enamel (oil base) won’t adhere to latex and latex won’t adhere to industrial enamel. You’ll have to get a primer paint that will adhere to both paints. Prime coat the existing paint and then put on the finish paint. There’s no reason though to use industrial enamel for a wall paint.

This article comes from askinglot edit released