Terms & Tools: Paints & Finishes
An historic waterbased paint created from animal glue and lime (whiting or chalk, a non-reactive form of carbonate.)
An extremely durable paint of crosslinked lime (calcium hydroxide or oxide) and milk that can further be made highly water-resistant and more durable by adding up to 5% raw linseed oil
A natural hard resin blended with drying oils (oleo-resinous) to produce varnishes, particularly for furniture and "coach" applications where high durability is required. Formed from fossilized plant extracts (e.g. formed under heat and pressure), the African "Zanzibar" form is the most durable.
A cross-linked polyacrylate (polymer of acrylic acid) elastomer used to thicken or gel a variety of aqueous and solvent preparations. These were originally developed for the cosmetics, paint, and pharmaceutical industries. In water-based preparations, Carbopol is often mixed with a base like NaOH, KOH, ammonia, or triethanolamine to produce a clear viscous gel; in solvents, complex "salts" of bases ( "ethomeens") with the polymer can form gel-like structures.
A plant resin drawn by tapping the Dipterocarpaceae tree of the East Indies. Predominantly blended with turpentine to produce spirit varnishes for coating paintings due to the clearness of the resin and its ability to saturate oil paints. Dammar has a lower tendency toward white "blooms" in high humidity than many other natural resins, and can be quite brittle as a coating material unless it is modified with the addition of small amounts of oils, waxes, etc.
A mode of failure where bonded layers of a material separate. Both manmade and natural materials can delaminate. Wood, plaster, paint and even stone can delaminate. Stone delamination, similar to exfoliation, occurs along the natural bedding planes. This kind of deterioration can occur when layers of a stone are laid skyward instead of horizontally, when expansion and contraction occur due to trapped moisture in the stone, by the expansion of rusting metal embedded in the stone, or by weathering caused by harsh conditions.
Fluorescence microscopy takes advantage of the ability of certain materials to absorb light at one wavelength and give it up or "fluoresce" the light at a longer wavelength to help characterize the constituent components of a material through routine microscopic examination. Fluorescent dyes, which carry reactive groups on them, have also been used in this regard to "tag" or make fluorescent certain common paint and varnish binding materials. Among these reactive dyes are Rhodamine B (which helps highlight oil-containing materials in paint and varnish samples); Alexafluor488 (which fluoresces proteins-containing layers); and TTC (triphenyltetrazolium chloride, which "tags" carbohydrates, such as gums).
Polycyclohexanone is a crystal-clear synthetic resin that can be dissolved in mineral spirits to produce a rapid-drying varnish that is resistant to yellowing in UV (though it tends toward yellowing in the absence of light); however these synthetic resins, such as Laropal, tend to be more brittle and risk oxidation over time that results in the need for aggressive polar solvent mixtures to remove.
A relatively low-volatility (low flammability and lower toxicity) petroleum distillate used as a slower-evaporating paint solvent (technically referred to as Varnish-maker's and Painter's Naptha, or VM&P)
A resin created by treating cotton or other cellulose products with nitric acid to produce solvent-soluble clear coating materials. It was found in the 1920s that this could produce a very durable, color-carrying lacquer. Used first as a paint to produce more than just black automobiles, it further found its way to other construction uses due to being the first easily sprayable quick-drying resin.
A mixture of a resin with a drying oil (such as linseed oil that begins self-polymerizing at room temperature in reaction to oxygen), producing a glossy, hard surface that maintains some elasticity and thus durability.
A natural resin formed from an annual exudation of the lac insect of southeast Asia, and India in particular, used for spirit varnishes (blended with alcohols). Shellac gives a hard surface that can be friction-polished to a very high gloss (french polish). Even when other preparations will be used for the finish surface, ethanol-cut shellac is commonly used to seal bare wood and raise the grain prior to a first sanding so that subsequent coatings will "take" evenly.
Varnishes that rely on fast-drying alcohol for their set, and thus require fast work on the part of an applicator. Examples of resins for spirit varnish are shellac and dammar.
This petroleum distillate is comparatively less toxic than many other paint-related solvents. It also has a slow rate of evaporation providing considerable "open" or working time before skinning or film creation when used as a thinner.
Copper salt, of various types. Also referred to as Copper(II) acetate. For centuries has been used as paint pigment for its blue/green color and as a fungicide. Different areas will have different kinds of salt: coastal will usually have more sodium chloride because of the ocean, urban/industrial areas will have more complex salts.
(PbCO3)2 Pb(OH)2 Pigment that was used in lead paint because of it opacity. A mixture of the carbonate and the hydrated oxides of lead. Also known as "flake white."
A coal tar distillate of benzene, this aromatic (sweet-smelling) solvent is used for thinning paints and is less volatile and slower evaporating than toluene.