Solar System Working Model

Rachel Said:

What should I use to form planets with concrete for my Eagle Project Solar System Model?

We Answered:

Use balls rather than bowls. Your smaller half sphere can be made freeform and your larger ones over baseballs to bowling balls to basketballs. You can immobilize your ball by burying it halfway it in a bucket of sand. Cut out a circle diameter of the ball out of tarpaper (roofing felt); placed this stencil over the ball to form your hemisphere/hump mold. Built up a layer of concrete, following the directions in the link below for hollow spheres. You just might want to put your balls in a plastic bag to protect the surface of the ball and for easy removal.

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