Potash (Potassium Carbonate)

Potassium Carbonate is a white salt, soluble in water (insoluble in alcohol), that forms a strongly alkaline solution. It is the primary component of potash and the more refined pearlash or salt of tartar. Historically, pearlash was created by baking potash in a kiln to remove impurities. The fine white powder remaining was the pearlash.

Potassium carbonate (called pearlash in old recipes) was often used to harden rosin in varnish recipes, especially for use on musical instruments. It is also used to emulsify wax to make Punic wax. The recipe for making Punic wax follows:

Werner of Neustadt found the following valuable process in making wax soluble in water. He took twenty-four ounces of potash (potassium carbonate) for each pound of white wax, which he dissolved in two pints of water, warming it gently. In this lye, he boiled the wax, cut into little bits, for half an hour, after which he removed it from the fire and allowed it to cool. The wax floated on the surface of the liquor in the form of a white saponaceous matter, and this being triturated with water produced a sort of emulsion, which he called wax milk or encaustic wax. This preparation may be mixed with various colors and applied in a single operation.

Source: "Encaustic Painting." The Encyclopædia Britannica: A Dictionary of Arts, Sciences, and General Literature. Volume 8. Original 9th Ed. in 25 Vols, William Robertson Smith, Editors, Day Otis Kellogg, Thomas Spencer Baynes, William Robertson Smith. Publisher Werner, 1903. p. 186.

Storage

Keep in a tightly closed container. Protect from physical damage. Store in a cool, dry, ventilated area away from sources of heat, moisture, and incompatibilities.

Health and Safety

WARNING! CAUSES IRRITATION TO SKIN, EYES AND RESPIRATORY TRACT. MAY BE HARMFUL IF SWALLOWED.

Wear impervious protective clothing, including boots, gloves, lab coat, apron, or coveralls, to prevent skin contact. Use chemical safety goggles and a full face shield where dusting or splashing of solutions is possible. Irritates the respiratory tract. Symptoms may include coughing and shortness of breath. Ingestion irritates the gastrointestinal tract. Symptoms may include nausea, vomiting, and diarrhea. It may have moderate toxic effects if consumed in large enough quantities. Refer to the Safety Data Sheet.

Environmental Hazards

No information is available about its potential environmental hazard. If the product is spilled, comply with Federal, State, and local regulations on reporting spills. Refer to the Safety Sheet and labels for further details.