Guide tofrenchpolishing


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Guide tofrenchpolishing

  1. 1. Restoration, Repair, & Finishing SuppliesLIBERON™/star star™Supplies, P.O. Box 86, Mendocino, CA 95460 • 707-962-9480 Guide to FRENCH POLISHINGFrench Polishing is the name given to the process Modern processing plants now exist for producingof coating wood with a solution of shellac machine made shellacs, similar to the hand madedissolved in alcohol, using a “rubber” made of rag varieties.and cotton wool instead of with a brush. The White and Transparent Shellac is made byalcohol evaporates, leaving the shellac deposited dissolving the Seed Lac in a hot caustic solution ofupon the wood. When applied correctly it water and then bleaching the solution withproduces what is possibly the finest looking finish chlorine. After bleaching the caustic is neutralizedfor furniture. Shellac was first introduced into with an acid, which causes the shellac to precipitateEurope about the 16th Century, but the term out of solution.FRENCH POLISH was not used until about In this form it is known as Bleached Shellac.1820, when the process was developed by a French Bleaching shellac alters its chemical properties, socabinet maker. that unless it is dissolved in alcohol within 3-4 days after bleaching, it will become insoluble.BASIC RAW MATERIAL Shellac contains a very small amount of wax from of FRENCH POLISH the insect. The wax is insoluble in alcohol andShellac is an encrustation surrounding an insect causes the cloudiness which can often be seenknown as Laciffer Lacca, which is a parasite living settling towards the bottom of the container.oh certain trees in India and other Eastern Transparent Shellac is made by removing the waxcountries. The insect is about a 50th of an inch from the bleached shellac by washing it with along and has a life cycle of about six months. petroleum solvent, which dissolves the wax but notThe shellac is gathered by cutting the infected the shellac.twigs from the trees. In this form it is known asStick Lac. The shellac is scraped off the twigs and FRENCH POLISHESwashed with water to remove the particles of wigs French Polish is both a proper and collective noun.and other impurities and when dry, is known as As a collective noun it covers all polishes madeSeed Lac. This is put into canvas tubes and heated with shellac and alcohol. As a proper noun it refersover a fire; One end of the tube is fixed and the to one specific type of material made from flakeother is rotated to squeeze the molten shellac shellac dissolved in industrial alcohol. It consists ofthrough the hessian as it melts. The initial shellac approximately 21/2 -3 lbs.. of shellac per gallon.that comes through is clean and small amounts are The type of shellac used can vary considerably indropped on to a cold stone, where it sets in the quality and colour, from pale orange to darkform of a thin disc up to about 3 in diameter. This known as Button Lac from which Button Polish French Polish is suitable for use on all dark woodsis made. The next amount of shellac that oozes and light woods, when a light to medium brownthrough may contain impurities which would tone is required. Button Polish is used to obtain aeasily be detected visually it the shellac was in the more orange or golden tone. On light coloured orform of a button and it is, therefore, stretched into bleached woods, where it is wished to retain thea thin sheet and crushed, when cold, into flakes, natural colour, White French Polish, which has afrom which French Polish is made. milky appearance, or Transparent Polish, which is almost clear, should be used. 1 of 4
  2. 2. Guide to French PolishingPREPARATION OF SURFACE There are several traditional methods of applying FOR POLISHING French Polish, but the method that follows isPreparation of the surface for French polishing is relatively simple and will produce an acceptableextremely important. Any slight imperfections high quality finish.which might not be noticeable under varnish or oil The actual process of polishing consists of bodyingfinishes would be apparent under French Polish. in, building up and spiriting out. The polish in allIt is essential, therefore, that the surface is clean three processes is applied with a “rubber” made byand fine sanded. Furniture that is being renovated wrapping a piece of unmedicated cotton wool in ashould be cleaned to make sure that it is free from piece of soft cotton or linen rag. An oldwax and grease. This can be done with white spirit handkerchief or a piece of cotton sheet would beand fine steel wool. If the finish on the furniture is ideal. The actual size of the “rubber” depends uponin a very bad condition, and is scratched or stained, the size of the hand and the size of the work beingit would be best to remove it completely with polished. A large “rubber” is best for say, a tablePaint & Varnish Remover. If, after stripping, the top, but a small “rubber” would be better for awood is still stained, it may be bleached with. a small item like a coffee table. The “rubber” is madetwo part Wood Bleach. by taking a piece of cotton wool, about the size ofIf the wood is open grained and a smooth mirror- a tennis ball, and moulding it into a triangularlike surface is required, the grain should be filled, shape which is then laid on a piece of rag, asbefore French polishing, with Grain filler, or extra shown in the illustration. The rag is then folded, ascoats of French Polish must be applied which are illustrated, to make a pear shaped pad. It is verythen cut back with fine glass or garnet paper until important that the bottom of the pad is perfectlythe grain has been filled with the polish. If the flat and does not contain any creases. If a piece ofwood is to be changed in colour, it may be stained stitched cloth has been used, it is also importantbefore French polishing, with Wood Dye. This is that no stitching is on the base of the pad. Thesupplied in 10 wood shades which may be inter- “rubber” should now be held in one hand and themixed to make a wide range of other shades. If the cloth carefully unwrapped so that the polish isgrain of the wood is to be filled with Grain filler poured into the cotton wool. On no accountand the colour changed, then the filler can be should the polish ever be poured on to the outsidemixed with the Wood Dye, so that staining and of the “rubber”, nor should the “rubber” be dippedfilling can be carried out in one operation. into the polish. By pouring the polish into theIt should be noted that wood can only be stained cotton wool and squeezing it out through the rag,to a darker shade than its existing colour. If the the rag acts as a strainer and ensures that nowood is required a lighter shade, then it must be scratches occur on the surface, due to any foreignbleached first with a two part Wood Bleach and body that may have inadvertently entered thethen stained to the required colour. polish. Sufficient polish should be poured into theHoles and cracks should be filled with Wood “rubber” until the cotton wool is saturated. Thestopping before polishing, but it should be noted rag should then be wrapped round the cotton woolthat where Wood stopping has been used, it will again to make the pear shaped “rubber” and thealways be noticed, as the pattern of the grain has “rubber” should then be pressed on to a spare piecebeen broken. The area filled with Wood stopping of wood or cardboard to squeeze out the excesscan be made less noticeable by painting a grained polish. If a “rubber” is used that is too wet, theneffect over the Stopping with artists colours and a ridges of polish will be left on the work, whichfine artists brush. could only be removed by rubbing down with abrasive paper.APPLICATION OF FRENCH POLISH The first applications of polish should be made byThere has always been a mystique about the art of rubbing up and down over the surface quickly withFrench polishing, but in fact it is a process that can the “rubber” without exerting too much carried out by any competent amateur after a As the polish in the “rubber” is used, the sides oflittle practice. the “rubber” should be pressed with the fingers and thumb to force more polish out.2 of 4
  3. 3. Guide to French PolishingAs the polish dries it is possible, when coating Unfortunately, French Polish tends to “sink” in thelarge areas, to make several applications of the grain and it is good practice, therefore, to leave the“rubber” by going from one end of the work back work for at least 24 hours before the final spiritingto the other. Small items should be left for a few out process, to make sure that further applicationsminutes for the polish to dry, before another are not required to fill the pores of the grain whereapplication is made. On no account should the the polish may have sunk in.“rubber” be passed over polish that is not dry, as it When a sufficient layer of shellac has been appliedwill remove polish that has already been applied. to the surface, the final operation of spiriting out isIt is possible that if wood has not been filled, the made and it is at this stage that the final high glossfirst coat of polish may make short fibers in the finish is obtained. The “rubber” should be chargedwood stand proud of the surface, in which case, with French Polish that has been thinned withafter the polish has been allowed to harden, the Methylated Spirits and at this stage the rubbersurface should be rubbed with the grain with fine should be squeezed so that it is almost dry. Whenflour or 910 Garnet Paper, preferably paper that dabbed on to a piece of white paper it should justhas already been used, so that only a mild cutting leave a damp impression. The “rubber” is thenaction is obtained. moved over the surface, using circular movements,Further applications of polish are made by using but finishing off in straight even sweeps backwardsthe “rubber” in a circular or figure of eight motion, and forwards with the grain sweeping on and offpassing quickly and lightly over the surface. It is the ends, as described above. The surface shouldimportant that at all times the “rubber” is slid on then be left to harden and the final process is thento the surface from the side with a gliding action carried out with a “rubber” that contains just aand lifted off in the same way. At no time should small amount of Methylated Spirits. One can usethe “rubber” ever be lifted from the work in the the same “rubber” by pouring in Methylatedmiddle or applied to the middle, as a mark will be Spirits and squeezing it until it is almost dry, or aleft, which will be very difficult to remove. For the fresh “rubber” can be made. The “rubber”, whichsame reason the “rubber” should never be left should be nearly dry, should be rubbed backwardsstationary on the surface, as the alcohol will and forwards over the surface, with the grain, withimmediately start to redissolve the polish that has considerable pressure. This action dissolves anyalready been applied. high spots on the surface and as the “rubber” dries.After the first few applications of polish, the it has a burnishing effect.“rubber” will not slide so easily over the surface, It is important that if at any stage of Frenchdue to the dissolving action of the polish on the polishing, a hole is worn in the rag, due to friction,shellac that has already hardened. A very small either a new piece of rag is used, or the rag is re-amount of Linseed Oil should then be applied to arranged so that the hole is not on the base of thethe base of the “rubber”. The best way of applying “rubber”.the oil is to dab a small drop on with a finger. If When French polishing work that may have carvedtoo much Linseed Oil is applied, the surface will areas, it is not always possible to use a “rubber”, inhave a smeary effect, as the linseed Oil does not which case the carved areas can be coated bydry quickly like the French Polish. Another applying the French Polish with a flowing action,problem that occurs when too much Linseed oil is using a bear hair or camel hair brush.used to lubricate the “rubber” is sweating on the Quite often, when wood has been stained, a coat ofsurface. French Polish will make apparent differences inAfter every 4-5 applications of the “rubber” the shade between one piece of wood and should be left for several hours to harden. In This often happens where a large area has beenbetween applications the “rubber” should be stored made by joining pieces of timber together. It isin a screw top jam jar to prevent it drying and possible to make lighter areas darker by dissolvingbecoming hard. A little Methylated Spirits can be aniline spirit soluble powders in Methylated Spiritsadded to the “rubber” whilst it is stored in the jar, and adding the coloured Methylated Spirits toto keep it soft and moist. If at any time the French Polish.“rubber” dries and becomes hard, it should bediscarded and a new one made. 3 of 4
  4. 4. Guide to French PolishingWhen colouring wood with tinted French Polish, Materials required:the French Polish should be thinned so that very • French Polish: Button, Garnet, Black,thin layers of coloured polish are applied to the White or Transparent French Polish.surface, otherwise ridges will be left where thecoloured polish has been applied. When the right • White Cotton or Linen Rag.shade has been obtained, French polishing can becarried out in the normal way, although it may be • Unmedicated Cotton Wool. (Cotton Waste)necessary to lightly sand the edges of the area • Linseed Oil.where the tinted polish has been applied. • Methylated Spirits. (Denatured Alcohol)Before attempting to French Polish an article offurniture, one should practice on a spare piece • Screw top glass jar.of timber, as it is not until one actually tries out • Rubber Gloves.the method described above that the meaningof the process will become clear. It is essential • Fine Abrasive Paper.that the French polishing operation is carried outin a warm, dry, dust-free room. If polishing is • For open grained woods:carried out in damp conditions, then “blushing” Grain fillerwill occur. This is a milky appearance which • For change of colour:develops as the French Polish dries and is not to be Wood Dyeconfused with “blooming”, which is a deposit likethe bloom on a grape, which can occur on the • For removing old finishes:surface of the polish at any time after it has been Paint & Varnish Removerapplied and which can usually be removed bywiping with a damp cloth. • For removing stains and lightening wood:A satin or matte finish can be obtained, after Wood BleachFrench polishing, by rubbing with 000 or 00 steel • For filling screw holes, cracks etc.:wool and wax polish, or by sprinkling pumice Wood stoppingpowder on to the surface and brushing with a softshoe brush. - 9/19/95 - lllll Email: Fax: 707-962-9484 • Toll Free Order Desk: 800-245-5611 Restoration, Repair, & Finishing Supplies LIBERON™/star star™Supplies, P.O. Box 86, Mendocino, CA 95460 • 707-962-94804 of 4