Here's a wrap on the wheel using Vine Black. I like the range of colors better than the previous but it was difficult to pull greens and violets. The yellow ochre was overdone, adding some opaqueness in the transitions. It's all good practice, though. Proper tempering, easy brush release to prevent dotting, waiting for a dry surface before the next coat, becoming aware of death-gripped brush--all these thoughtful little things...
I again tried a wet finger to the gesso in an attempt to eradicate pinholes. Same results--no help at all. Then came sanding with 600 grit CAMI (~P1200) that on first glance appeared to provide remedy. Alas, no luck. The tiny holes were merely filled with gesso dust. Once a bit of tempera was applied, the holes jumped right out.
A quote from one of my main resources seems appropriate:
The secret of success
By the time the gesso has been strained, it will probably be so cool that it will soon set to a jelly. When this happens, place it over the hot water for a moment, stirring it slowly but constantly with the brush, and it will become liquid again in a moment. As soon as it is liquid, take it off the hot water. Never let it stand over hot water a second longer than is absolutely necessary, or you will find your gesso full of air bubbles, if not of worse defects. The importance of this simple precaution cannot be overemphasized.
Thompson, Daniel V. Jr. The Practice of Tempera Painting. New York. Dover Publications. 1962. (Yale University Press. 1936.) p. 27.