Sometimes the shellac cannot be melted when it is stored in alcohol for too long. This is due to the polymerization reaction of the resin contained in the shellac. Polymerization of the shellac reduces its solubility in alcohol. If the shellac flakes cannot be melted, it will cause waste. Is there any way?
Way is when dissolving shellac sheet, add in the concentrated sulfuric acid (1 gram) that weight is shellac sheet (such as 100 grams) 1% in alcohol, after treating that shellac sheet fully dissolves, then neutralize with potassium carbonate (appropriate amount), then Potassium sulfate and other precipitates precipitated in the alcohol solution are filtered to obtain the regenerated shellac liquid. The luster and drying performance of this regenerated shellac solution are worse than those prepared from normal shellac sheets, so it can only be used in combination with normal shellac solution.
