ASPHALTUM-PLUS

Asphaltum-plus is a variation on a printer’s resist that combines three important elements in the following amounts:

·    6 parts liquefied asphaltum (for acid resistance)

·    3 parts beeswax (to keep the formula from becoming brittle)

·    1 part rosin (for especially good adherence to the metal)

Use a combination of rubbing alcohol and turpentine as a solvent/thinner.  If your asphaltum is in powder form, mix it with thinner until completely smooth and the consistency of cooking oil, before beginning to measure amounts.  Break the beeswax into chunks and put it in a can or jar placed in a vat of hot water on a hot plate or electric stove.  Do not use a gas stove since the open flame increases fire danger.  After the beeswax has melted, add the asphaltum and stir to combine.

In another container immersed in the hot water bath, mix the rosin with a solvent composed of equal parts turpentine and rubbing alcohol. (Alcohol and turpentine form an immiscible liquid that must be stirred or agitated frequently to keep it from separating.)

When the rosin has completely dissolved, slowly add it to the beeswax and asphaltum, stirring constantly until all the ingredients are completely mixed together.  Remove from the heat and, as the mixture cools, stir every few minutes to keep the rosin from settling out.  The mixture will stiffen as it cools, and should be thinned with the turpentine and alcohol.  When at room temperature, asphaltum-plus should be the consistency of Coco Lopez, refried beans, or chocolate pudding (depending on the ethnic background).  It helps to make a sizable amount that can be transferred to smaller containers for different tasks:  the thickness of latex house paint for painting designs, thicker for painting edges etc

From: A Manual of Cloisonné and Champlevé enamels by J. Patrick and Judith Lull Strosahl and Coral Barnhart