Cardboard hemispheres?

Question

I am working on a science project and I need cardboard hemispheres. In a project, I would glue carboard hemispheres to the back of a posterboard to show the solar system. Plastic hemispheres work two but they need to be hollow so i can put a light in them. Lightweight is good too so they dont bend the poster, otherwise I would use paper mache. Where can I find cardboard hemispheres, preferably at a store than over the internet?

Answer 1

I don't think you'll easily find cardboard (or cardstock) hemispheres or even spheres you could cut in half.

You could always cut some plastic (play or sports) balls in half though.

Or you could make your own lightweight hollow hemispheres by covering just half of a sphere of some kind like a ball or balloon or even large lightbulb, etc. (or cover a hemisphere like the back of a round bowl) with papier mache.  You could even use a very lightweight paper if you need the finished object *really* lightweight, like tissue paper--colored tissue paper even) then letting it dry.  (Dried papier mache is actually very light when there's nothing under it... and not any heavier than cardstock or cardboard for sure.)

You can put some plastic wrap over the sphere or hemisphere first so the papier mache will release easily, or even use a layer of Vaseline as your release.

You may need to cut the edge of the hemisphere smooth after drying and popping off the form after it dries.  

Or you could do the same thing using "paper pulp" you make at home (or just buy Celluclay at a craft/hobby store)... those and the papier mache would all leave a surface that's not completely smooth, but you can always sand those things smoother (using a temporary support underneath), or add a layer of Creative Paperclay to that, or just a smoother layer of the pulp/Celluclay.

Or for a smoother surface from the start, you could use Creative Paperclay alone, though that would get more expensive if you need to use a lot of it.

HTH,

Diane B.