W, Y. (walnut oil - yellow ocre)

Walnut oil - A natural, colourless drying oil pressed from the nuts of a walnut tree, Juglans regia. Walnuts contain approximately 65% oil. The cold-pressed oil is pale yellow while the hot-pressed oil has a green tinge. Walnut oil dries slower, yellows less and cracks less than linseed oil; it dries faster than poppy seed oil. It was popular as a paint medium in Italy, the Netherlands and Germany. Walnut oil will turn rancid and develop a strong odour on storage. 
The application of oil, including nut oil, to the surface of stucco marble has always been quite common in order to increase the gloss of an already well polished surface. 
Synonyms: nut oil
Wittenburg (1999); Museum of Fine Arts, Boston (2000)

Water glass  Na₂O.xSiO₂ - An aqueous solution of sodium silicate prepared from silicon dioxide (SiO₂) and sodium oxide  (Na₂O) in a ratio that varies from 2 to 3.5. Water glass forms a hard glasslike mass when it dries. A water glass solution is viscous and has little tack, so when it is used as an adhesive pressure must be applied to hold materials together while bonding. The dried product is brittle and water sensitive. Aluminium salts can be added to the formulation to improve water resistance. Water glass has been used to make artificial stone. It was tried unsuccessfully as a binder in the 19th  century for fresco paintings. Calcium water glass was used in the Ransome process of stone preservation. This procedure used alternating solutions of an alkaline silicate and calcium chloride to form insoluble calcium silicate (calcium water glass) in the pores of the stone. Potash water glass is composed of potassium silicate. Double water glass is a mixture of equal parts potassium silicate and sodium silicate.
Synonyms: soluble glass; soluble silicate; liquid glass; aqueous sodium silicate; flint liquor; silicate of soda; waterglass; water-glass; calcium water glass; double water glass; potash water glass
Museum of Fine Arts, Boston (2000)

Water lime - A type of lime, calcium oxide, that will harden under water. Water lime, or hydraulic lime contains a mixture of lime and clay. Water lime is not the same as lime water. 
 Synonyms: hydraulic lime
 Museum of Fine Arts, Boston (2000)

Wattle  -  Wooden rods or stakes which can be interlaced with twigs or branches to make walls or fences, or more commonly, to form the basis of panels in traditional timber framed buildings which are then covered with  daub 
English Heritage (2000)

Wattle and daub -  A building material composed of interwoven sticks, twigs or branches plastered with clay, grease or mud. Wattle and daub construction was used for roofs, walls and fences, especially in the early 19th  century.
Synonyms: Willow
Museum of Fine Arts, Boston (2000)

Wax - A solid or semi-solid substance that is slightly greasy to touch. Waxes are composed of long chain hydrocarbon compounds, and may contain esters of fatty acids and alcohols. They are thermoplastic and melt at low temperatures (<100°C). In general, waxes are water-repellent, smooth and soluble in organic solvents. Waxes are classified by their origin:  - animal: beeswax, lanolin, spermaceti, shellac wax  - vegetable: carnauba, candelilla, bayberry, Japan wax - mineral: paraffin, ozocerite, ceresin, Montan - synthetic: polyethylene, polymethylene, Carbowax®, Halowax Waxes are used for sealants, coatings, adhesives and waterproofing. Wax is mentioned as a substance used for coating and polishing the surface of stucco marble.  Wax (or wax in turpentine, carnauba wax or beeswax) was usually applied to the surface with a linen cloth and the treatment was usually carried out after the polishing with oil.
Synonyms: animal wax; beeswax; lanolin; spermaceti; shellac wax; vegetable wax; carnauba; candelilla; bayberry; Japan wax; mineral wax; paraffin; ozocerite; ceresin; Montan wax; synthetic wax polyethylene wax; Carbowax®; Halowax
Museum of Fine Arts, Boston (2000);  Wittenburg (1999)

Wetting agent - A component added to a liquid to decrease its surface tension and thus increase its ability to wet, or spread, over a solid surface. Wetting agents are sometimes added to watercolour paints. Examples of wetting agents are: surfactants, soaps, alcohols, gum arabic, ox gall and fatty acids.
Museum of Fine Arts, Boston (2000)

White coat (finish coat) - A lime-putty plaster coat with a trowelled finish. 
RS Means Building Glossary (undated)

White glue - A common name for milky white adhesives composed of aqueous emulsions of polyvinyl acetate. White glues are widely used. They are easy to work with and effectively bond most materials. Most white glues contain numerous additives, such as tackifiers, plasticisers, antifreeze solvents and biocide preservatives. Most white glues will soften when soaked in water and will yellow in sunlight.
Synonyms: CM Bond®; Titebond; Rhoplex® N-580; Elmer's® Glue-All [Borden]; Bulldog Grip®
Museum of Fine Arts, Boston (2000)

White lime - Another name for whitewash.
Museum of Fine Arts, Boston (2000)

White Portland cement - A cement produced from chalk and china clay, burnt using oil fuel instead of coal. The strength of white cement is rather less than the strength of ordinary Portland cement.
Ashurst (1983)

Whiting - A fine powder of white chalk (native calcium carbonate). Whiting has been used as an inert pigment in paints. Synthetically prepared calcium carbonate, called precipitated chalk, is much whiter and finer than whiting.
Synonyms: whitening; Spanish white; limestone whiting; Paris white; English white
Museum of Fine Arts, Boston (2000)

Whitewash - An inexpensive white paint. Whitewash contains lime suspended in water. Other additives can include: glue, whiting, salt or sugar. The non-permanent water soluble paint was used on walls and ceilings.
Synonyms: white lime; limewash
Museum of Fine Arts, Boston (2000)

Wood fibre plaster -  A plaster reinforced with wood chips used in the 1800's. Fibre plaster was generally used as thick base coat on wooden laths.
Museum of Fine Arts, Boston (2000)

Xonolite - Calcium silicate monohydrate (C3S5H), a natural mineral that is readily synthesized at 150o - 350oC under saturated steam pressure. Xonolite is  a constituent of sand-lime masonry units. 
RS Means Building Glossary (undated)

Yellow ochre - A natural yellow earth mineral primarily composed of goethite (iron hydroxide) and clay. Yellow ochres occur naturally throughout the world and have been used as a pigment since prehistoric times. Synthetically produced yellow ochre pigment, introduced at the end of the 18th  century, is sold under the name of Mars yellow.
Synonyms: goethite; yellow ochre; Mars yellow
Museum of Fine Arts, Boston (2000)
 
 

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