When was shellac first used

Natives of the Far East had laboriously cultivated and processed the shellac by hand, scraping the branches encrusted with the lac bug secretions, forcing the secretions into muslin, and holding long muslin bags of the secretions over the fire to liquefy and purify it.

They pulled it by hand into huge sheets and then broke the sheets into flakes for re-moisturizing later. Hand processes were partially replaced by the mid-nineteenth century. Just as the lacderived dye was about to fade in popularity, industrial plants began processing the lac secretions for use as a wood sealer and finish.

In , William Zinsser founded Wm. Zinsser's shellacs were soluble in ethyl alcohol and were the first quick-drying, tough, colorless finishes available in the United States. Shellac was particularly popular late in the nineteenth century and in the early twentieth century when houses were being quickly built in early subdivisions at break-neck speed—shellac was an ideal wood finisher because it was so fast to dry and several coats could be applied in a single day.

A shellac known as buttonlac, a very dark shellac, imparted a very deep walnut color to inexpensive woodwork that people then found very desirable. Shellac is generally made from two ingredients, raw seed lac and ethyl alcohol. In fact, most companies want to purify shellac as completely as possible—impurities from the bug, the cocoon etc. Shellac is generally shipped in dry or flaked form and is re-moisturized with an alcohol solvent, generally denatured alcohol.

Some companies add ingredients to lengthen the shelf life of their product but will not reveal these proprietary additives. Shellac that is bleached or made into clear shellac are dissolved in sodium carbonate and centrifuge to remove insolubles and then bleached with sodium hypochlorite.

In certain seasons of the year, these insects swarm in huge numbers on the trees, settle on branches, and project protrusions into the tree to penetrate the bark. They suck up the sap and absorb it until they feed themselves to death called the feast of death amongst the indigenous peoples.

At this same time, propagation continues, with each female lac bug laying about 1, eggs before dying. The sap is chemically altered in the lac bug's body and is then exuded onto the tree branch.

On contact with the air, the excretion forms a hard shell-like covering over the entire swarm. This covering forms a crust over the twig and insects. And this is the point of this short history. No furniture or cabinet manufacturer uses shellac as a sealer. Only woodworkers who read the magazines, or are told by someone who does, think they should always use shellac as the sealer. This is laid aside to cool and harden, after which it is broken into flakes.

If there is a demand for it, the bhilwaya will opt instead to make button lac. Instead of stretching the molten lac into sheets, the bhilwaya takes the lac from the twisting bag with a spatula and spreads it out in the form of a circular disk or button about one to three inches in diameter.

Before it hardens completely the button is stamped with the seal of the manufacturer. Shellac manufactured by modern mechanical methods is called machine-made shellac, mainly to distinguish it from shellac made by the indigenous — and, frankly, more fascinating — hand technique.

There are two processes - one based on melting heat process and the other on solvent extraction. In the heat process, seedlac is melted on steam-heated grids. The molten lac is forced by hydraulic pressure through a fine wire screen.

The filtered shellac, still molten, is collected and transferred to a steam-heated kettle from which it is dropped onto rollers. It is squeezed out on the rollers, coming off as a thin sheet to be broken into flakes. The thickness of the flake is controlled by adjusting the roller pressure. All flake shellac produced by this process contains wax.

For the wax-containing grade, raw seedlac and alcohol solvent are charged into a dissolving tank. The solution is refluxed for an hour or so and then filtered to remove insolubles. The filtered shellac is fed to a series of evaporators where it is concentrated into a viscous melt, which is then dropped onto rollers that sheet it out for removal in flake form.

Darker, wax-containing flake shellacs such as Garnet are made this way. Dewaxed shellacs are made by dissolving seedlac in either cooled alcohol of a very high proof or heated alcohol of a lower proof.

The resulting solution is then passed through a filter press to remove the wax, after which the filtered shellac is then concentrated in evaporator tanks. The viscous shellac is then rendered into flakes. Dewaxed Lemon and Dewaxed Garnet shellacs are manufactured using this process. By varying the amount of carbon, contact time and quality of the seedlac, one can obtain grades of shellac ranging in color from light amber to extremely pale straw.

Although most of the bright red lac dye can be removed with activated carbon, some shade of red-orange remains. For many applications, however, a nearly colorless film is preferred. Kusmi shellac, while extremely light in color, is very expensive and not available in commercial-scale quantities. The development of shellac bleaching in the early 19th century solved this problem with a relatively inexpensive process that could produce enormous quantities of very pale-colored shellac.

Since establishing the first U. The bleaching process involves dissolving seedlac, which is alkali-soluble, in an aqueous solution of sodium carbonate.

The solution is then centrifuged or passed through a fine screen to remove insoluble material. The next step is bleaching the cooled solution with dilute sodium hypochlorite to the desired light color. The shellac is then precipitated from solution by the addition of dilute sulphuric acid, filtered off, washed with water, ground and dried in vacuum driers.

The final product has a granular consistency and is dissolved in alcohol to give a milky, creamed-honey colored solution. While more efficient equipment and machinery have replaced much of the work that was done by hand in the 19th and early 20th centuries, the bleaching process itself has not fundamentally changed in over years.

Bulls Eye Shellac is manufactured in a 3-lb. It refers to the number of pounds of shellac dissolved in one gallon of alcohol. A 3-lb. Freshly made shellac dries very quickly to a hard, durable and water-resistant finish. However, because it is a natural material, shellac is also perishable and after six months an ordinary solution of shellac and alcohol begins to undergo a chemical change: it gradually takes longer to dry; the dried film is softer and more prone to scratches and water damage.

This change is even more pronounced for bleached shellac. After 18 months it may take hours to dry or not even dry at all and is considered to have expired. Exposure to heat also accelerates the expiration process. Zinsser research chemists have succeeded in prolonging the shelf life of shellac in two ways: the first involves a specially formulated solution; the second involves a patented process U.

Patent No. Bulls Eye Shellac is the only pre-mixed shellac in the world guaranteed to dry quickly to a hard, durable, finish for 3 years after the date of manufacture. However, since storage conditions can greatly affect the shelf life of our shellac always check the manufacturing date to find the freshest Bulls Eye Shellac and apply some of the product to a test surface to check the dry time and film hardness.

To ensure the long life of Bulls Eye Shellac keep the container tightly closed and store in a cool, dry place where the temperature does not exceed 75o F. Extreme heat can ruin shellac in less than a week. There is no need to worry about cold weather: since shellac is alcohol-based it is unaffected by freezing temperatures.

Rich yellow-orange in color. Shellac can be applied by practically any method — brushing, padding, or spraying. Most common applications are a simply brushing on a thin even coat for a finish.

Never shake or power mix shellac, it imparts air bubbles and moister in the finish which are very difficult to remove later without completely removing the failed finish. Preparing shellac requires only a slow hand stirring with a flat paint stick. Natural finish prefers natural brushes; Fitch brushes are usually pure skunk hair, but some have soft badger hair on the outside to produce a smooth finish and a center of skunk hair to give the brush body.

Pure white china bristle scores a second tier, and is best if your use will be sporadic and a more disposable price tag is required. Never use a synthetic brush, or absolutely never a foam brush. Before brushing saturate the brush with alcohol from tip to ferrel, metal band around brush handle, to activate the brushes ability to smoothly hold and transfer your finish. This also makes the brush easier to clean later. Wipe it clean against the edge of a can before dipping into your shellac.

Dip the brush halfway into the shellac each time you need to refresh it, bring the brush out and let the excess shellac run off, then drag it lightly across the top of the jar, or can your using. Starting about 2" in from the edge, drag the brush lightly to the edge, then come back all the way to the other edge. Carefully watch the edges for drips and keep a pad handy to remove them before they begin to dry.

Dry drips, flying spits, or runs - otherwise known as goobers, can be removed after the finish dries but are much easier to deal with while its freshly applied. Shellac dries quickly, learn to overlap your coats quickly or distinct lines will form between brush lines. Avoid covering an area with more than brush strokes in each area per coat. There is no issue with air bubbles unless you "slap" the brush against the surface. Never stop short on any surface, in fact never stop short on a piece.

Finish should be applied from start to finish, nonstop. It will take coats to reach a deep rich and durable finish. Brush cleaning can be done with alcohol solvents, but standard ammonia cleans shellac brushes because the alkaline ammonia dissolves the acidic shellac. Soap and water finishes the job, and the soap helps soften the bristles. A less known and practiced technique is called padding, a process that takes advantage of shellac's rapid drying capabilities and produces a fine thin layer without brush marks or drips.

Padding works best on flat surfaces, but can be useful on carving or rounded areas once you gain some experience. Use a 2 lb. It should be as lint-free as possible.

Do not use cotton T-shirt type cloth or cheesecloth, and most definitely never use a paper towel! Cut a piece of cloth roughly 10"" square, then fold it up into a pad, a pre-made pad is easier. Pour about 1 ounce of alcohol on the cloth and work the alcohol into the cloth. Then take a squirt bottle of shellac and dispense several thimble-fulls of shellac into the pad.

There are two basic methods, a strait along the grain technique that starts a motion before the surface and ends after the pad breaks contact, much like following through with a baseball bat swing or leading with a shotgun at a flying target. On an average size surface, you can return to the start by the time you reach the end and pad on several layers.

The second technique is a circular method, pressing lightly and pushing the shellac almost burnishing into the pours of the wood.

This method takes some practice and you must carefully sense the status of the pad, adding a small amount of shellac continuously to prevent it from sticking. The heat of friction rapidly dries the shellac, and if waxed shellac is used begins to polish the surface.

Keep doing this until the surface is tacky and the pad starts to stick. Between wipes, pad the edges. The trick to this is to apply light coats of shellac by keeping the pad moist, not dripping wet. If you can squeeze shellac from the pad, it's too wet. You can prolong the life of a bad between sessions by keeping your pad in a tightly wrapped zip lock back, or a small jar with a tight cap.

When the pad begins to fray, discard it - a few cents in cotton will waste hours of work if you impart fibers into your finish. The first application of shellac, brush, spray, or pad, should penetrate quickly and be dry enough to scuff-sand with sandpaper, this removes the raised fibers in about an hour. After the first coat, rub using to maroon synthetic fiber pads or regular steel wool between applications. After three coats, let the finish dry for twelve to twenty-four hours, depending on humidity.

It takes three to five coats to reach a full polished finish. Then rub the finish out with steel wool, using wax thinned with mineral spirits as a lubricant. Products like Briwax are perfect for this process. After the wax dries to a haze, wipe the excess wax off with a soft cotton cloth, and then polish with a nylon stocking.

This leaves a very mellow, hand-rubbed satin finish. Shellac surface repairs are simple, apply a thin coat of alcohol on a pad, and then lightly work as if applying a coat. For more substantial finish damage use a 1lb cut instead of just alcohol. You can fill deep scratches using a heavy cut 4lb or more applied with an artist's brush like a 1 or 2.

If the scratch has gone through the finish and the stain, you can mix the shellac with alcohol soluble dyes or pigments to match to original color. White water spots can be treated the same way, but usually only with straight alcohol.

Another common practice is the use of shellac sticks, colorized solid shellac employed by melting it into cracks, chips, scratches or depressions. The use of a burn-in knife and chemicals that prevent the shellac from sticking to surrounding areas in the hands of a skilled artist can erase damage such as dog chews or dents. To test for a shellac finish, dab some alcohol on an inconspicuous area such as behind a leg.

If the finish gets tacky, it's shellac. Artisans specializes in shellac finish restoration and reproduction, and can provide all related services. Although many have conceded or celebrated demise of shellac's dominance as a furniture finish, antique collectors and restorers find this a sin, these artificial finishes may be perceived as waterproof and more durable, but they hide the natural beauty of wood under a cataract of plastic film.

Despite the attempts by scientists to duplicate shellac synthetically, and the thousands of useful products resulting from their efforts, a little Indian bug still secretes the best and most astonishing furniture finish. Educational Home. Online Tool Museum. Woodworking Glossary. American Architecture. Artisans Bookstore. Article Library. Concise History of Period Furniture. Educational Trips.

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