Using sandarac for retouch varnish - making a white goo ball
I’m making a batch of Iris Carr’s retouch varnish which calls for shellac dissolved in alcohol and sandarac dissolved in alcohol. The sandarac gets strained and then added to the shellac solution.
I’ve made this recipe several times before, using the same sandarac and shellac. Usually I pour out a weight of finely ground sandarac into a jar, add the alcohol, and heat the jar (~200º C for about an hour) to speed up the sandarac dissolving. Then I put the shellac in a separate jar with alcohol and by the time the sandarac has fully dissolved the shellac has dissolved as well. I pour the sandarac through a coffee filter into the shellac, stir it up and it’s ready to go. This time there is a white goo settling to the bottom of the jar of sandarac. With heat, the goo becomes more liquid and can get swirled into the rest of the liquid, but as soon as it cools the goo reforms and sinks to the bottom.
I don’t remember having this issue before. Should I filter out the goo? Is the goo the important part and I need to keep cooking it until it breaks down completely? Should I not be heating the sandarac at all and just let it sit for days until it breaks down on its own? Would love to know if anyone else is familiar with this and can give some insight.