What's the best way to make a hemispherical 4 foot radius concave Mirror?

I want to make a two piece reflective (on the inside) sphere big enough for a person to comfortably stand in. What would be the best way to go about this?

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Kiteman5 years ago
(Why do I get the horrible thought that he's going to try and get a tan with this?)
Burf5 years ago
A Mylar balloon, shiny side in.
frollard Burf5 years ago
I wonder if a balloon could be inflated, then structurally supported from the outside (fiberglass, etc) to create such a sphere... It can be done with smaller balloons obviously, but not sure about 4ft.

@author - what 4-foot-tall sphere can anyone stand inside comfortably?
jcox12 (author)  frollard5 years ago
Sorry 4 foot radius that would be 8 foot diameter.
a fiberglass sphere I could make, but how to make it reflective that's the real challenge.
frollard jcox125 years ago
Start with the mylar balloon - then coat its pressurized outer surface with fiberglass - it would maintain the mirror on the inside.
There are companies who will put an aluminiumised layer onto it to make a mirror.
What QUALITY of reflector are you looking for ? So you can see your face in it ?

If you need that kind of quality, you need to look at acrylic domes - not cheap, but not as expensive as you might think. I know a specialist in the UK that makes them.