Pontypool japan is a name given to the process of japanning with the use of an oil varnish and heat which is credited to Thomas Allgood of Pontypool. In the late 17th century, during his search for a corrosion-resistant coating for iron, he developed a recipe that included asphaltum, linseed oil and burnt umber. Once applied to metal and heated the coating turned black and was extremely tough and durable.
Pontypool is in a steep valley in South Wales, surrounded by coal and iron working. The iron used was produced by the furnaces of Blaenavon to the north, and most of the "Pontypool ware" was actually produced in nearby Usk or Newport, at the southern end of the valley.
In the late 17th century, there was a developing trade in metal goods made of thin iron sheet, spurred by development of the rolling mill. Rustproofing this iron was important. Tin plating had been developed in Germany, and British manufacturers needed to compete.
While it was the growth of the iron foundries and tin plating that gave birth to japanning on metal, tin plated iron was not the only metal used. There are examples of brass, copper and bronze used as substrates. In France copper was the metal primarily used. Because it had to be hammered into shape rather than rolled and stamped the surface was uneven. [1] This did not provide the best surface for japanning thus it has a greater tendency to flake off than the smoother English tinware. When the French made tinware it was often trimmed with bronze.
The use of metal allowed a variety of forms that were required to withstand heat and water. Coffee pots, tea sets, candle sticks and other household items could all be japanned and decorated in the popular fashion.
These japanned metal objects are very stable so a great many still survive. Many pieces survive today with little rust. In most cases it is easy to ascertain the underlying metal because it can be seen in losses or scratches. If the japanning is intact, a magnet can be used to identify iron. Most iron trays show some rust on the back where only a single coating was applied. Even the tin plated iron objects show rust in some areas.
It is worth remembering the unavailability of effective paint, at this time. The surface finishes that did exist either had poor adhesion to their substrate, or required either a porous or an organic substrate to bond to. Today's resin-based paints for metals had not been invented.
Similar recipes or "secret varnishes" were also used in Birmingham. In his book on Pontypool japan (W. D. John, 1953), [2] published one of the recipes the workmen had handed down through generations:
The linseed oil was heated together with the umber and the asphaltum while the litharge and cobalt were added slowly. According to the recipe, the varnish was ready when a drop of varnish dripped onto cold glass remained in a ball. After cooling, the turpentine was added. There was also a pale clear version which omitted the asphaltum and the cobalt. [2] In modern tests, this varnish worked equally well on papier mâché and metal plates. Three coats produced a durable glossy black finish. [3]
This recipe is similar to one for gold size published by both (Robert Dossie, 1764) [4] and (Stalker and Parker, 1688). [5] In that version, linseed oil is boiled together with gum animi, asphaltum, litharge and umber in approximately the same proportions as the Pontypool recipe. (Watin, 1755) [6] also describes the use of asphaltum as an addition to the well-known spirit varnishes of the day. It appears that the secret recipe for Pontypool japan had been in existence for some time before its use for japanning metal.
Jacques Maroger was a painter and the technical director of the Louvre Museum's laboratory in Paris. He devoted his life to understanding the oil-based media of the Old Masters. He emigrated to the United States in 1939 and became an influential teacher. His book, The Secret Formulas and Techniques of the Masters, has been criticized by some modern writers on painting who say that the painting medium Maroger promoted is unsound.
Paint is any pigmented liquid, liquefiable, or solid mastic composition that, after application to a substrate in a thin layer, converts to a solid film. It is most commonly used to protect, color, or provide texture. Paint can be made in many colors—and in many different types. Paint is typically stored, sold, and applied as a liquid, but most types dry into a solid. Most paints are either oil-based or water-based and each has distinct characteristics. For one, it is illegal in most municipalities to discard oil-based paint down household drains or sewers. Clean-up solvents are also different for water-based paint than they are for oil-based paint. Water-based paints and oil-based paints will cure differently based on the outside ambient temperature of the object being painted Usually, the object being painted must be over 10 °C (50 °F), although some manufacturers of external paints/primers claim they can be applied when temperatures are as low as 2 °C (35 °F).
Electroplating, also known as electrochemical deposition or electrodeposition, is a process for producing a metal coating on a solid substrate through the reduction of cations of that metal by means of a direct electric current. The part to be coated acts as the cathode of an electrolytic cell; the electrolyte is a solution of a salt of the metal to be coated; and the anode is usually either a block of that metal, or of some inert conductive material. The current is provided by an external power supply.
Varnish is a clear transparent hard protective coating or film. It is not a stain. It usually has a yellowish shade from the manufacturing process and materials used, but it may also be pigmented as desired, and is sold commercially in various shades.
Lacquer is a type of hard and usually shiny coating or finish applied to materials such as wood or metal. It is most often made from resin extracted from trees and waxes and has been in use since antiquity. The term originates from the Sanskrit word lākshā (लाक्षा) for lac bug, representing the number one hundred thousand (100,000), used as wood finish in ancient India and neighbouring areas.
Rosin, also called colophony or Greek pitch, is a solid form of resin obtained from pines and some other plants, mostly conifers, produced by heating fresh liquid resin to vaporize the volatile liquid terpene components. It is semi-transparent and varies in color from yellow to black. At room temperature rosin is brittle, but it melts at stove-top temperature. It chiefly consists of various resin acids, especially abietic acid. The term colophony comes from colophonia resina, Latin for "resin from Colophon", an ancient Ionic city.
Oil paint is a type of slow-drying paint that consists of particles of pigment suspended in a drying oil, commonly linseed oil. The viscosity of the paint may be modified by the addition of a solvent such as turpentine or white spirit, and varnish may be added to increase the glossiness of the dried oil paint film. The addition of oil or alkyd medium can also be used to modify the viscosity and drying time of oil paint. Oil paints were first used in Asia as early as the 7th century AD and can be seen in examples of Buddhist paintings in Afghanistan. Oil-based paints made their way to Europe by the 12th century and were used for simple decoration, but oil painting did not begin to be adopted as an artistic medium there until the early 15th century. Common modern applications of oil paint are in finishing and protection of wood in buildings and exposed metal structures such as ships and bridges. Its hard-wearing properties and luminous colors make it desirable for both interior and exterior use on wood and metal. Due to its slow-drying properties, it has recently been used in paint-on-glass animation. The thickness of the coat has considerable bearing on the time required for drying: thin coats of oil paint dry relatively quickly.
Japanning is a type of finish that originated as a European imitation of East Asian lacquerwork. It was first used on furniture, but was later much used on small items in metal. The word originated in the 17th century. American work, with the exception of the carriage and early automobile industries, is more often called toleware.
Plating is a surface covering in which a metal is deposited on a conductive surface. Plating has been done for hundreds of years; it is also critical for modern technology. Plating is used to decorate objects, for corrosion inhibition, to improve solderability, to harden, to improve wearability, to reduce friction, to improve paint adhesion, to alter conductivity, to improve IR reflectivity, for radiation shielding, and for other purposes. Jewelry typically uses plating to give a silver or gold finish.
Japan black is a lacquer or varnish suitable for many substrates but known especially for its use on iron and steel. It is so named due to the history of black lacquer being associated in the West with products from Japan. Its high bitumen content provides a protective finish that is durable and dries quickly. This allowed japan black to be used extensively in the production of automobiles in the early 20th century in the United States. It can also be called japan lacquer and Brunswick black. Used as a verb, japan means "to finish in japan black". Thus japanning and japanned are terms describing the process and its products.
A coating is a covering that is applied to the surface of an object, usually referred to as the substrate. The purpose of applying the coating may be decorative, functional, or both. Coatings may be applied as liquids, gases or solids e.g. Powder coatings.
Tinplate consists of sheets of steel coated with a thin layer of tin to impede rusting. Before the advent of cheap milled steel, the backing metal was wrought iron. While once more widely used, the primary use of tinplate now is the manufacture of tin cans.
A tinsmith is a person who makes and repairs things made of tin or other light metals. The profession may sometimes also be known as a tinner, tinker, tinman, or tinplate worker; whitesmith may also refer to this profession, though the same word may also refer to an unrelated specialty of iron-smithing. By extension it can also refer to the person who deals in tinware, or tin plate. Tinsmith was a common occupation in pre-industrial times.
Tinning is the process of thinly coating sheets of wrought iron or steel with tin, and the resulting product is known as tinplate. The term is also widely used for the different process of coating a metal with solder before soldering.
Perilla oil is an edible vegetable oil derived from perilla seeds. Having a distinct nutty aroma and taste, the oil pressed from the toasted perilla seeds is used as a flavor enhancer, condiment, and cooking oil in Korean cuisine. The oil pressed from untoasted perilla seeds is used for non-culinary purposes.
Electroless nickel-phosphorus plating is a chemical process that deposits an even layer of nickel-phosphorus alloy on the surface of a solid substrate, like metal or plastic. The process involves dipping the substrate in a water solution containing nickel salt and a phosphorus-containing reducing agent, usually a hypophosphite salt. It is the most common version of electroless nickel plating and is often referred by that name. A similar process uses a borohydride reducing agent, yielding a nickel-boron coating instead.
An oil drying agent, also known as siccative, is a coordination compound that accelerates (catalyzes) the hardening of drying oils, often as they are used in oil-based paints. This so-called "drying" occurs through free-radical chemical crosslinking of the oils. The catalysts promote this free-radical autoxidation of the oils with air.
Electroless nickel-boron coating is a metal plating process that can create a layer of a nickel-boron alloy on the surface of a solid substrate, like metal or plastic. The process involves dipping the substrate in a water solution containing nickel salt and a boron-containing reducing agent, such as an alkylamineborane or sodium borohydride. It is a type of electroless nickel plating. A similar process, that uses a hypophosphite as a reducing agent, yields a nickel-phosphorus coating instead.
Chemical coloring of metals is the process of changing the color of metal surfaces with different chemical solutions.