Square up a block with a chainsaw
For a large sphere  freeze 2 pcs. together
This cube is 15” x 15” x 15”

Starting with a perfect cube will allow you

to make a nice sphere

Multiply the width of the cube by .29
(Example- 15 x .29=4.35”) Scribe lines
on all sides of the cube 4.35” from the edge

Use a Layout Jig to scribe the lines

With a chainsaw cut off the 4 corners
(Hexagon from top view)

Be careful not to cut inside the lines

Rotate the Ice & cut off 4 corners, using the lines as guides

Notice the foam under the carving?  This protects your saw

Rotate the ice & cut off 4 more corners, again use the lines as guides

Using a sharp chisel
Carve 3 hoops around ice

Using the chisel
Remove the 8 humps

Using a Sphere scratchy board
Remove the high spots

Scratch the whole surface
in a circular pattern

Using sand paper
sand the whole surface

Spray with a hose set on gentle.