While early shellac was less refined adding to the darker coloration homeowners looked for a deep rich color so contractors tinted the shellac. Today, many woodworkers find fault with shellac because of unused shellac that has been mixed degrades over time — that is another reason for the lack of respect. Degradation effects drying times and the film finish stays softer and is more easily scratched.
Eventually, as the degradation continues, if you use outdated product, you end up with a gummy mess with which to deal. Experience taught me this lesson, so I watch my expiration dates closely. Shellac is sold pre-mixed in cans or is sold in flakes that you mix, when needed, with alcohol. Obtaining the date of mixture is easy when you mix your own shellac, but because you need time for the flakes to dissolve in alcohol, some woodworkers balk at mixing their own.
Pre-mixed shellac, in the United States, is sold by Zinsser. Zinsser shellac has a company-reported shelf-life of three years from the date of manufacture.
The company provides codes printed on the can lid that indicate the date of mixture, but you have to decipher that code. A typical code found on a can lid might be SBD. The first number after the letter is the year the shellac was mixed.
In this case, you see 0 which indicates If the number was 1, it would represent , and 2 would indicate The first number after the year indicator is the month of mixture. In the example, 7 indicates the month of July. Easiest to Apply: Wipe on polyurethane Spray on poly from a can Spray lacquer from a can -All three are easy options Easiest to Repair: Lacquer -Spraying on another coat partially dissolved the coat underneath, leading to perfect repairs.
Easiest to Clean Up: Waterborne polyurethane -Soap and warm water. It is made from the dried secretions of the female Lac beetle. Once they are dried, collected, and processed, you can dissolve them in a solvent such as alcohol.
And then it can be used as a finish. Prior to the s shellac was probably the most popular form of topcoat. Shellac is also popular because you can put a a color or a tint into it.
And it holds that color very well. Shellac is very beautiful and forms a reasonably durable finish that can be high gloss in nature. It does have drawbacks however. If you place a hot mug or a hot pan onto a shellac finish, a white ring can develop under it.
It is also soluble in alcohol. So if you spill an alcoholic beverage onto it, The finish will start to dissolve. It is extremely durable and one of the hardest of the topcoat finishes. It is stronger and better wearing than shellac and varnish. Lacquer is also capable of producing an extreme high gloss finish. Lacquer is impervious to alcohol and most other common household liquids that might be spilled on it.
There are two classes of lacquer. Those that dry with solvent evaporation, ie. And those that dry via a chemical reaction. These are called catalyzed lacquers. They are generally found at a specialty paint store, and have a very short shelf life.
Lacquer can be bought in all finishes; from matte to high gloss. Lacquer is the most forgiving of all topcoats. Remove any sanding residue. Apply subsequent coats the same way.
After the first coat, sand only if you need to smooth the surface or to correct mistakes. After three or four coats you should have adequate film thickness to rub out with grit sandpaper or steel wool. The thicker cut stays in the core until you give it a gentle squeeze.
First, place your mixed shellac into a squeeze bottle applicator. Next, construct a pad. Cut a inch square of lint free cotton or linen cloth. Now, fashion a golf ball-sized lump from cotton or gauze. Dampen the center of this cloth with denatured alcohol, as shown in Photo D. As with brushing, maneuver the pad with brisk, deliberate strokes, slightly overlapping each previous pad stroke. To minimize pad marks, touch the pad down onto the surface, move through the stroke, and raise it at the end.
Recharge the pad when the shellac stops flowing Photo E. When the surface is covered, let the shellac dry for two hours before gently sanding with grit stearated sandpaper to smooth the surface. This time allow four hours for drying between coats. Sand again only to smooth the surface or remove finish imperfections. Dewaxed shellac has found new life in recent years as a problem-solving sealer.
You can use premixed dewaxed shellac, like SealCoat, or mix your own. Aerosol cans are perfect for sealing or finishing smaller projects. Here are four problems shellac can readily solve.
Multi-function sealer. Shellac sticks to everything, and everything sticks to shellac. This helps when refinishing antiques that might still have residues from polishes, oils, or other mystery contaminates. Similarly, shellac can serve as a sure-fire sealer between potentially incompatible finishes, such as oil stains and waterborne topcoats. Odor blocker. A light coat of shellac can quickly fix an old piece that smells musty, or a new project that still reeks of finish months after it was applied.
Blotch resistor. Shellac seals thirsty patches of wood, and provides a base of color. Apply a half-pound cut of shellac, sand the surface, then apply stain.
Color enhancer. Some woods—figured woods included—suffer from poor stain absorption. Colored shellac can be used much like a toner or light dye stain to provide some color while enhancing the grain. Similarly, a coat of super blonde dewaxed shellac can provide the faintest hint of yellow under a clear waterborne to prevent the washed-out look that comes with most acrylics.
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Pro Shop. Taking Stock. This Business About Woodworking. Resource Guide. Bench Top Tools. Fixed Machinery. Raw Materials. Woodshop Environment. Woodworker's Showcase. Special Marketing Section. Sponsored Content. History For about a hundred years, from the s to the s, shellac was the primary finish used for all coats by all small shops and factories.
Then three things happened that almost totally ended shellac being thought of as a complete finish: Oil-based polyurethane became available.
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