Shellac is used when painting wood to seal knots and resin pockets, and to cover surface stains.
A good shellac is made of 99% alcohol and contains no water. Water creates pores, which damages the surface of the wood. Selder & Co's shellac is made of shellac flakes and 99% alcohol.
Pour a small amount of shellac at a time in a disposable container. Use a simple brush - containers and brushes used cannot be cleaned. Apply evenly. Ingredients: isopropanol, shellac flakes.
Time needed to dry: half an hour to an hour.
WARNING: highly flammable liquid. Do not expose to heat, sparks, fire or hot surfaces. No smoking.