Hello all: I inlay my brass pieces into cavities that I carve into the stone dial face. I make the cavity about 1/16 th inch deeper than the thickness of the brass and 1/16 th inch wider around the edges.
I use 50 year clear silicon in the cavity. The 1/16 th inch gap prevents the brass from touching the stone, cushions the brass, and allows for thermal expansion of the brass. Silicon has given me very good results. I also use a silicon layer when mounting a sundial to its pedestal with good results. With a great deal of effort, brass that has been inlaid with silicon can be pried loose. John Carmichael Tucson Arizona
