Natural resins for varnishing and polishing
Autor: stuarts brasil | Publicado: 2009-03-26T19:12:00-07:00

<!--[if gte mso 9]>     Normal   0                         MicrosoftInternetExplorer4   <![endif]--><!--[if !mso]>  st1\:*{behavior:url(#ieooui) }  <![endif]--> <!--  /* Font Definitions */  @font-face  {font-family:Wingdings;  panose-1:5 0 0 0 0 0 0 0 0 0;  mso-font-charset:2;  mso-generic-font-family:auto;  mso-font-pitch:variable;  mso-font-signature:0 268435456 0 0 -2147483648 0;}  /* Style Definitions */  p.MsoNormal, li.MsoNormal, div.MsoNormal  {mso-style-parent:"";  margin:0cm;  margin-bottom:.0001pt;  mso-pagination:widow-orphan;  font-size:12.0pt;  font-family:"Times New Roman";  mso-fareast-font-family:"Times New Roman";} @page Section1  {size:595.3pt 841.9pt;  margin:27.0pt 90.0pt 27.0pt 90.0pt;  mso-header-margin:35.4pt;  mso-footer-margin:35.4pt;  mso-paper-source:0;} div.Section1  {page:Section1;}  /* List Definitions */  @list l0  {mso-list-id:1502506025;  mso-list-type:hybrid;  mso-list-template-ids:2113706824 134807553 134807555 134807557 134807553 134807555 134807557 134807553 134807555 134807557;} @list l0:level1  {mso-level-number-format:bullet;  mso-level-text:;  mso-level-tab-stop:36.0pt;  mso-level-number-position:left;  text-indent:-18.0pt;  font-family:Symbol;} ol  {margin-bottom:0cm;} ul  {margin-bottom:0cm;} --> <!--[if gte mso 10]>   /* Style Definitions */  table.MsoNormalTable  {mso-style-name:"Table Normal";  mso-tstyle-rowband-size:0;  mso-tstyle-colband-size:0;  mso-style-noshow:yes;  mso-style-parent:"";  mso-padding-alt:0cm 5.4pt 0cm 5.4pt;  mso-para-margin:0cm;  mso-para-margin-bottom:.0001pt;  mso-pagination:widow-orphan;  font-size:10.0pt;  font-family:"Times New Roman";}  <![endif]-->  The alcohol available to wood finishers in earlier days was often of unknown quality, it was usually distilled from wine or brandy, and may easily have contained up to 50% water, as there was no readily available way of measuring the water content in the alcohol. This water causes the varnish to become cloudy, so it was of more than interest sake to measure accurately the purity of the alcohol used in varnish making. An early method was to put a quantity of gunpowder in a spoon and cover with the alcohol to be used for polishing. This was set alight and if, after the alcohol has burnt off, the gunpowder would ignite, it was counted as pure enough to use, if the powder would not ignite, then it contained too much water and would be discounted from use. Later the use of the hydrometer meant that a careful calculation of the purity and water content could be made.   Some of the basis of varnish is natural resins, differing locations of these resins and their differing inherent nature, was the diference for many styles of polishes and varnishes.  Anime is the archaic name for      fossil copal resin. Fossil resins are mined from deposits found      underground, they are found in areas of prehistoric forest, and as such      the resin is virtually exhausted today. The original resin the word anime      refers to copal resin and is no longer available, but Kauri resin, from New        Zealand, is a certain substitute for      the original resin. Kauri resin is a superior quality resin, and makes      fine quality varnish, used extensively during the 1800’s as the ingredient      in most fine quality varnishes, used in both oil and spirit varnishes.Balsam is a resin collected from      coniferous trees such as pine, fir, spruce, balsam, and larch. It was      historically considered an inferior ingredient in varnishes, but was used      to give the varnish a high gloss. It may be seen to be refered to in old      recipes, as chian turpentine (derived from Mediterranean pines), Strasburg      turpentine (derived from German fir trees), and Venice      turpentine (derived from European larch trees). Balsam should not be      confused with modern turpentine, the product that is now sold as      turpentine, was called turpentine oil or spirits of turpentine, and is a      liquid solvent made from the distillation of pine-tree sap. The balsam      that is available today, is called copaiba balsam and Canadian balsam. Benzoin is a resin from the styrax      benzoin tree that grows in tropical Asia. It was      used in spirit varnishes of the 16th and 17th      centuries. It has a pleasant odour that is still faintly recognisable on antiques,      and for this reason is often added to classic varnishes to reproduce the      characteristic smell. In old formulas, it may well be referred to as      Benjamin.Copal , various resins have been      called copal, some types of copal can be mixed with oils to make oil      varnish, and the copal varnish sold in art supply stores, is an oil-based      varnish. The type of copal used in spirit varnishes is called spirit or      manila copal. This resin is harvested from the trees of the Agathis genus,      and is used as an additive to give toughness to the varnish.Elemi is a soft resin produced by      the trees of the Burceraceae family, and is added to varnishes to make      them more elastic. In old formulas it may be found to be called allemy,      and may be bought in art supply stores.Gum      Arabic is a resin produced from the trees of the Acacia genus. It is      included in some old formulas for spirit varnish, and also is used by      artists as a resist, this can also be bought in art supply stores.Lavender oil is oil distilled from      the lavender plant, and first produced during the 1500’s, being very      similar to turpentine oil, but that turpentine oil will not mix with      alcohol, while lavender oil will. It is used in spirit varnishes to make      the varnish level out and smooth more easily, so the brush marks flow out      better. It may also be refered to as oil of spike or spike lavender.Mastic is a soft resin that is      very clear, with a pale yellow colour that may darken with age, and was      used in the past when a pale light-coloured varnish was required or desired.      It is harvested from the Pistacia lentiscus tree that grows in the      Mediterranean region. The best mastic comes in small drop shaped beads      called ‘tears’, these have been harvested while still attached to the      tree. The lower grades of mastic have been harvested from the ground, and      contain impurities. Mastic can be bought in art supply stores.Rosin is the resin that is left      after the balsam from the trees such as pine, fir, spruce, balsam and      larch, is distilled to make spirits of turpentine, and like balsam, it was      considered an inferior ingredient in varnish, but used to give varnish a      high gloss finish. In old formulas it may well be referred to as      colophony, when it was derived from the American pine trees, or as greek      pitch, when it was derived from the Aleppo      pine.Sandarac is a brittle resin,      derived from the Alerce tree (Tetraclinus articulate) that grows in the Atlas       mountains of North America, and Cypress      pine trees (Callistris quadrivalvis), in old formulas, it may be refered      to as gum juniper. It was probably the most widely used resin for varnish      making, because it is very clear and dissolves easily in alcohol. Since      sandarac, used alone, forms a very brittle film, elemi was often added to      sandarac varnish to improve its elasticity. Sandarac varnish starts almost      colourless, but with age it becomes darker and slightly reddish. The best      quality sandarac is harvested while still attached to the tree, and is      called ’tears’ of sandarac, the lower grade is harvested from the ground      and contains impurities. Sanarac also can be obtained in art stores.Shellac is unique amongst natural      resins, since it is produced by insects on a plant. Shellac varies in      colour depending on  the shellac      used. Early varnish formulas used seed-lac, button-lac, or orange shellac,      and the varnish produced had an orange or dark brown colour. Seed-lac was      considered the best for use in spirit varnish during the 1600’s, and it      produced a lighter colour of varnish than the orange shellac. In older      formulas, when gum lac is specified, kausmi seed-lac is probably being      referred to. When old formulas specify shellac, it is appropriate to use      the orange shellac. Lighter coloured shellacs were not available until the      late 1700’s, although shellac was used in a limited way for a long time,      its dark colour made it less desirable, at a time when finishers were      striving for a pale light-coloured finish with the varnish. After lighter      forms of shellac became available, it soon became one of the most sort and      used components in a spirit varnish.To give an idea of the different varnishes available to artists during the 1800's. here are some of the types that were sold by colourmen such as Windsor &amp; Newton, Reeves, Roberson and Rowney, from 1800 to 1890.Mastic varnish later called mastic varnish for varnishing pictures           1835Copal varnish later called copal (oil) varnish                                             1835Copal spirit varnish later called white copal spirit varnish                        1856Fine picture copal varnish                                                                           1835White spirit varnish                                                                                     1835Brown spirit varnish                                                                                   1835Transfer varnish                                                                                         1835Double mastic varnish later called doble strength for Magilp                 1840White lac varnish also called lac varnish                                                 1840Crystal varnish later refered to as crystal or map varnish                      1840Caustic or transfer varnish                                                                       1840Raising varnish                                                                                         1840Roberson's fixing liquid for chalk and pencil drawings, in bottles         1840Grecian varnish                                                                                        1840Field's white lac varnish                                                                           1870Photographic varnish for negatives                                                         1870Amber varnish light                                                                                  1883Amber varnish dark                                                                                  1883Soehnée varnish                                                                                        1883Soehnée Frére's varnish for pictures                                                        1890Soehnée Frére's varnish for paper and etc.                                              1890Picture copal varnish                                                                                1890Paper varnish                                                                                            1883Vibert's vernis á retoucher                                                                        1896Vibert's vernis á tableaux                                                                          1896Mastic varnish No 2 for pictures                                                              1896Rowney's picture glaze                                                                             1907.