Mirror blanks from inflatable balls

A method for manufacturing an assembly including hollows, sealed glass balls for use in constructing a mirror blank, comprising the steps of:

• a) arranging the hollow, sealed glass balls in close proximity to each other in between a front face sheet and a back face sheet to permit fusing upon expansion;
• b) surrounding the glass balls with a vented edge glass;
• c) fixing an initial internal pressure within the glass balls;
• d) applying heat to soften the glass balls and increase pressure within the glass balls as the glass balls fuse with each other during expansion, forming cells,
• wherein as a result of fusing, the glass balls contact the front face sheet as a result of the increased pressure within the glass balls;
• e) restricting the expansion of the glass balls to force the glass balls into a densely packed array of cells;
• f) annealing and cooling the mirror blank to ambient temperature;
• g) venting the cells to equalize internal and external pressure on the front and the back face sheets;
• and
• h) keeping the cells vented in the assembly.