I won my physics class egg drop challenge and three years of California MESA competitions in high school using spray insulation foam to make molds of specific eggs.
The MESA rules were 14" diameter max, no liquids, no parachutes, dropped from 60'. I cut a pattern of holes in cardboard and sprayed the foam over the eggs (lubricated with PAM), pulled the cardboard off, lubed them up on that side, and sprayed the other side. I trimmed the whole container to a sphere a little over 14" diameter and then compressed it as much as I could (Literally having someone stand on top of it) and wrapped it tightly in tape.
My best record using this method was 32 eggs with 100% survival.
The MESA rules were 14" diameter max, no liquids, no parachutes, dropped from 60'. I cut a pattern of holes in cardboard and sprayed the foam over the eggs (lubricated with PAM), pulled the cardboard off, lubed them up on that side, and sprayed the other side. I trimmed the whole container to a sphere a little over 14" diameter and then compressed it as much as I could (Literally having someone stand on top of it) and wrapped it tightly in tape.
My best record using this method was 32 eggs with 100% survival.