Historic gums and resins

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ResinsI found the following list here. It contains lots of information on historical material that was used in the varnish and paint industry. When you are a violin maker you come across lots of ancient materials and it can become very confusing. This list is quite accurate but not exhaustive at all. Interesting stuff...

 


Gums and resins

The following is a list of gums and resins traditionally used in furniture finishes. They are all natural exudation from either trees, the fruits of trees or from parasitic insects that feed on trees. It seems appropriate that they also produce the best finishes for wood. The color, density, hardness, brittleness and durability range greatly. Some are soluble with single solvents while others can be solved with several solvents. The dates in parentheses are earliest recorded date of first use.

 

Amber (14c)

Fossilized tree pitch, usually from evergreens, does not yellow. Baltic amber is the most common. The hardest natural resin known. Can be solved with turpentine and some can be solved in alcohol. Undissolved collections in the bottom of the mixing containers should be remove, dried out and solved with another solvent. An ingredient in the finest varnishes. From dark, to red, to orange, to pale, to white or clear. Lumps and powder.

Ammoniacum (14c)

Gum Ammoniac, a gum resin from an Umbellifera, Dorema ammoniacum. Yellow to white brittle gum. Soluble in alcohol or water, should be warmed. Porcelain cement.

Arabic (15c)

Gum Senegal, Gum Acacia is a water soluble from the Acacia trees. Excellent for gold leaf application, can be mixed with rabbit skin, parchment or other glues. Good base for water colors.

Balsam (12c)

Canadian, this hard resin is from evergreen trees and vary from clear to yellow. Known for its optical properties, very clear. Medicinal properties, good incense. Solvents: Turpentine and Alcohol. Tears, powdered or liquid.

Benjamin (1571)

Gum Benzoin, generally yellowish balsamic resin occurs from pink to light blue is hard and alcohol soluble. Excellent resin for fine varnish, Siam gum (pink) is a valued incense. Has properties. Should be mixed with other resins. Lumps, powdered and tears.

Burgundy Pitch

Obscure varnish ingredients used in the nineteenth century from the pitch of the Norway spruce. White Burgundy pitch was used in a paint recipe ca.1815.

Catechu (1683)

Resinous extract from Acacia catechu: leaves and twigs. Lacquer and varnish ingredient. Soluble in water and alcohol. Japonica, Terra Japonica, Gambir.

Colophony (14c)

Rosin is a byproduct of turpentine distillation or pitch evaporation. Used in varnish manufacture. Too brittle to be used alone but will catalyze to the hardest resin in the mixture, weathers well. Soluble in alcohol or turpentine. Broken chunks to powder. This is the material with which you rosin up your bow.

Copal (1577)

Resins, new or fossil from various tropical trees. Hard, dense resin, clear to light yellow. Excellent optical qualities and is durable in the weather. Soluble in turpentine and linseed oil and alcohol. Hard copals are called Kaurie and soft copals are grouped and called Anime (animi). Excellent for cements. Kauries are difficult to solve. Available in all forms: tears lumps, powder, liquid, etc.

Dammar (15c)

Damar is a clear to yellow, hard resin from various conifer trees. Excellent for fine art varnish, not very durable. Soluble in alcohol or turpentine, solves with turpentine even after drying. Granules or powder. Yellows on exposure to UV, and will eventually yellow anyway.

Dragons Blood (14c)

A deep red resinous gum exudation of the fruits of a rattan palm. Soluble with alcohol or water. Makes an excellent varnish, can be extended with less expensive gums and resins. Prized incense and smells delightful when being applied as a varnish. Available in reeds, cakes or pieces. Decant the lees.

Elemi (1837)

Gum elemi, resin elemi, from tropical trees of the Burseraceae family, used for ink, cement, varnish and lacquer. Very pleasant odor, repels insects. Quickly soluble in (warm) alcohol and soluble in turpentine, insoluble in water. Soft and must be mixed with harder gums and resins. Available in sticky lumps. Gumbo limbo.

Gamboge (1712)

A gum colored from orange to brown from the Asian tree (Garcinia spp.) Transparent, used for aging and coloring gilding and watercolors. Considered a premium gum, usually commands a high price. Soluble in water or alcohol.

Lac (1688) Japan Wax (1859)

Japanese Lacquer, Chinese Lacquer (1592) is the fat sap or milky juice of the berries of Rhus vernicifera or R. succedanea, Asian sumacs, Varnish Tree (1758). This is how the beautiful Oriental Lacquer is accomplished. Authorities say that this is the only true ""lacquer"" Soluble in warm alcohol. Urushi.

Mastic (14c)

European tree (Pistacia spp.) of the sumac family producing a thick flexible gum. High quality varnish suitable for fine art and photographic touch up. Soluble in alcohol or turpentine. Cement ingredient. (Cyprian turpentine).

Sandarac (14c)

From Callitris spp. From a conifer is a translucent hard but brittle resin for incense and varnish. Alcohol or turpentine soluble. Produces a high shine and comes in light yellow to clear, few inclusions. Excellent for cements and available in tears, must be strained or decanted.

Shellac (1713)

Known since the 15th century. Excrement from Lacca lucifera (or Lucifera lacca), a parasitic bug living on an Asian fig tree. Collected, cleaned and sold in stick lac, seed lac, buttons, flakes or ground and solves with alcohol that should be strained. A finish that has not been duplicated synthetically. Introduced to Europe in the early 1700’s and was quickly the vogue. The chief and some say only ingredient in French Polish.

Tragacanth (1573)

From Astragalus gummier, a yellowish, expensive gum water soluble (swells to a gel with water). Because of its pharmaceutical use, this is currently the most expensive gum together with amber. Available in granular and ribbon form.

 

Glues, adhesives and cements

This is a description of materials that were traditionally used to attach various materials together. Important distinctions need to be made in order to clarify different properties of the materials.

Adhesive - to attach together with another substance, usually introduced between materials and physically attach each different material together.

Cohesive - to attach together without another substance, usually molecular bonding of materials. This is done with materials that melt or bond materials by slightly dissolving each surface.

Glue - the substance to attach materials together (adhesive), this material is the physical bond that in its strength holds divergent materials together.

Cement - the substance used to attach materials together, this bonding material can act as both a physical bond as well as a chemical bond.

All of these sticking materials are organic in nature and largely unaltered from their original states in nature. These are the materials that have been used for centuries, are still available today and should be used in restoration work to replace exactly the original materials. Other benefits include health considerations, most are a proteinaecous base and quite safe.

Hide glue

Ox hide

Generally considered the finest and strongest of organic glues. This material from rendered down hides of old oxen or cattle, provides the darkest, most durable and possesses the greatest strength. Water soluble, it by itself is not waterproof. Other natural materials can be added to many of the hide glues to make them waterproof. The materials (hide glues) have a shear strength slightly less than that of modern epoxies.

Horse hide

Made of horse hides usually provided by slaughter houses. An excellent quality glue, however if younger hides are used the glue will not be as strong as if made from older animals. Does not possess the strength and toughness of ox hide glue. Hooves are sometimes added to hide glue mixtures, although hooves make good glue they are not as strong as straight hide glue.

Skin glue

Rabbit

Made from rendered down rabbit skins, this glue as well as sheep shin or parchment glue could be listed as hide glues but the thinner more delicate nature of the material makes the distinction important. While rabbit skin glue has many applications in fine art and especially gilding, its structural strength is very weak and should not be used for gluing any material under stress.

Sheep

Sheep skin or parchment glue is also rendered down by boiling the skins in water as with all hide and skin glues. The animal hides or skins are cleaned of their interior membranes and all hair. The hides are allowed to dry, cut into pieces and boiled in water. After a thick accumulation form on the top of the boiling solution, it is collected, dried and broken into usable pieces. Any impurities should be strained before drying.

Fish

In certain applications the skins of fish are rendered down to produce serviceable glues. North American Indians used these glues as well as glues from skins, hooves, horns, sinews and tendons for glue. Generally mixed with pigments and used for painting and decoration of artifacts.

Vegetable

Starch

Many fine glues and adhesive pastes can be made from a variety of natural starches from vegetables. Wheat starch is used for wallpaper paste. Rice starch can be used to attach fine papers to other materials. Potato starch is another inexpensive adhesive materials.

Other materials

 

Blood

Straight fresh blood or dried blood meal can be used by themselves as a glue however they are usually added to other glues as a good protein extender. Many applications including mixing with linseed oil and dirt to form hard dirt floors in cabins, the glue also adding a deep red color to the floor.

Fish float bladders

Especially the float or sound bladders from sturgeon fish. Can be added to hide glues and other glues to provide waterproofing properties. Excellent for gold leaf work as well as structural applications. Russian is the best.

Hooves

The hooves (feet) of various animals, including horses, cattle, sheep and goats provide an excellent protein based glue. Not considered as strong as hide glue it is frequently used in mucilage and lighter duty glues.

Tendons and sinews

These materials have a substance that hold the long fibers together. This substance is water soluble and can be used for gluing arrow heads and feathers on arrow shafts. Also used as a binder in painting and decorating.

Eggs

The entire egg both white and yoke can be used for light duty gluing. The whites of eggs (albumin) is called "glair" and is insoluble in water after it dries. Many applications including use by the Indians.

Cheese/milk

These glues are based upon the substance casein that can be removed from milk or cheese. This is an excellent light duty glue, used especially in fine art applications, although if properly used this glue has great strength.

Historic pigments and dyes

This is a list of various materials that were traditionally used in furniture and fine art to provide the different colors used in the original manufacture of valued antiques and artifacts. Dyes are indicated with an "*". The dates given in parentheses are the first known used of the particular words for the materials, although the materials may have been used earlier. Fugitive colors fade on exposure. Reactive pigments may or may not change or react to a variety of outside or inside influences.

Reds

Spanish Brown (c1800)

Red Iron Oxide imported from Spain. The deposits of pigment occur nest to the Iron Mines. Excellent opacity an chromatic intensity this traditional ‘barn red’ pigment can be manipulated. Red Earth.

Venetian Red (1753)

A hematite mineral pigment, lighter red pigment mentioned in many early recipes for paints and advertisements for pigments.

Indian Red (1750)

Yellowish red earth pigments varies to reddish brown, from India and Persia.

Turkey Red (1789)

Iron oxide pigment, similar to Venetian red, darker and more intense.

Cochineal* (1583)

This red dyes comes from a cactus feeding beetle, usually from Mexico. It takes 7000 bodies (abdomens) per pound.

Alkanet Root* (14c)

Purple red dye and stain from Alkana tinctora, of the borage family. Used exclusively with linseed oil and especially suited for mahogany. Both stains and chemically changes mahogany. Fugitive and reactive with certain woods.

Terra de Sienna (1787)

This material becomes reddish brown when cooked (burnt, calcined) and yellowish brown when in a raw or uncooked (unprocessed) state.

Red Lead (1732)

Called Minium, heated or burnt white lead turns to red lead (lead oxide), base for mahogany graining with excellent opacity. POISON

Vermilion 14c)

Called Cinnabar this material is an orange red mercury sulfate, used for base coat for mahogany graining and as a base under tortoise shell. POISON

Rose Pink (1825)

This is a moderate pink colored earth pigment.

Pernambuco* (1559)

Derived from Brazil wood and produces a red purple wood dye. The shavings from the wood are of equal value to the wood itself, which is used for violin bows.

Dragons Blood

See Gums and Resins

Red Vitriol* (14c)

Iron Sulfate, reactive. POISON

Browns

Burnt Umber (1568)

Is a maganese and iron oxide, lighter when in raw form and darker when burnt (calcined). One of the most common early pigments.

Van Dyke Brown (1850)

This pigment comes from bog earth, peat or lignite base, does not mix well with water or alcohol bases, good for oils and reactive.

Yellows

Ocher (14c)

Ochre is a naturally occurring impure iron earth pigment comes in yellows and less often in red. Yellow ocher can be turned red by calcining.

Chrome Yellow (1819)

Lead chromate is a brilliant yellow pigment. POISON

Annatto Seeds* (1629)

Yellow to red dyestuff, fugitive.

Litharge (14c)

This material is a fused lead monoxide, light yellowish white. POISON

Naples Yellow (17c)

Yellow oxide of lead. POISON

Montpelier Yellow (18c)

Yellow oxide of lead. POISON

Gamboge

See Gums and Resins

Brimstone (12c)

Sulfur, Yellow Stone.

Blacks

Black Iron Oxide (14c)

Black, black and does not turn blue when lightened from natural deposits.

Ivory Black (1634)

Bone Black from bone or ivory burned (calcined) in the absence of oxygen and is a blue black.

Lamp Black (1598)

Is from collections of soot from various carbon producing (based) fuels.

Smalts Black (1558)

This pigment is produced from fused sand and coloring agents to produce a brilliant black pigment with optical properties.

Frankfort Black (1815)

Imported German black pigment.

Whites

Lead Oxide (11c)

White lead is made with sheets of pure lead that are exposed to a contained atmosphere of acid vapors, usually acetic acid. Deposits form on the surfaces of the sheets, is scraped off and ready to use. Excellent opacity and adds drying properties to paint and varnishes. Also called Flake White. POISON

Zinc Oxide (1849)

When zinc plates are exposed to acid vapors, the residues removed and are ready for use, much safer than white lead it has good opacity.

Titanium Dioxide (1796)

Although this pigment was in existence during this early time it was not readily available until the twentieth century, an excellent white pigment.

Talc (1610)

Talc is made of powdered soapstone, fiberous magnesium silicate with flat platelets similar to mica.

Whiting (14c)

Calcium carbonate or chalk it is used as a filler, flattening agent and paper filler. Mixed with linseed oil to produce putty.
Spanish White (1824) A very fine white grade of whiting, used for gilding base and for marbleizing base coat.

Marble Dust (13c)

Powdered white stone marble, used for gilding and scagliola (marbleizing using real stone materials).

Mica (1777)

Flat thin leaves of crystallized mineral silicates and has iridescent properties.

Greens

Chrome Green (1824)

A chromium compound of copper is an excellent green pigment. Not as fugitive as other period green pigments. POISON
Verdigris (14c) Produced from a reaction of copper and acetic acid (copper acetate) and is fugitive. POISON

Green Vitriol* (14c)

Sulfate of copper created by a reaction between copper and nitric acid. reactive. POISON

Copperas* (14c)

Iron Sulfate, reactive. POISON

Blues

Prussian Blue (1724)

Ferric ferrocyanide is the bluest blue. Very intense absolutely brilliant blue. Traditionally used to paint the mantles of the Madonna by the masters. Used to paint the interiors of antique furniture especially china cupboards. Also used for architectural coloring, interior and exterior. Can be mixed with yellow ocher to produce a durable green color. Not poison.

Ultra Marine Blue (1598)

Is powdered lapis lazuli, semi precious and expensive.

Smalts Blue (1558)

Ground fused sand and finely ground cobalt colored glass. Brilliant durable pigment, refractive qualities.

Blue Vitriol* (14c)

Sulfate of iron, reactive. POISON

Leads, chromes, cobalts and mercury compounds are deadly poisonous heavy metals. Always use caution when handling, especially their fine dust. Other copper, sulfate and acetate mixtures can also be deadly. Use precaution when handling these hazardous materials. These compounds should be used with binders that are durable and should have varnish or shellac protection over them to prevent them from rubbing off.

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