How to cut a Jolly Ball in Half Cleanly

[sms]

I'm making an integrating sphere to measure lumens and I need to cut a

14" Jolly Ball in half along the seam.

Any ideas on how to rig up a jig to do this?

This guy did it but I can't figure out how to cut it cleanly.

[TimR]

Drill 1/4 hole end to end.

Insert threaded rod through, secure with nuts and washers.

Chuck rod in drill press or lathe, touch with utility knife while spinning.

[Vic Smith]

Mark your line off and use an electric jigsaw. You don't need a jig.

[nestork]

Can you do this:

Use a felt pen to mark a line perpendicular to the seam across the seam.

Cut along the seam with a jig saw and then press glazing channel onto both rough cut edges. You could spread the glazing channel open with your fingers and apply a slow curing construction adhesive to the inside of the channel before pressing it onto the rough cut edge of each hemisphere.

Here's what glazing channel looks like:

or at least one kind of glazing channel anyway. Glazing channel comes in different sizes and cross sections. You can buy glazing channel to accomodate every thickness that plate glass comes in.

Align the felt pen marks on both hemispheres and have helper hold the two hemispheres together while you apply pieces of duct tape across the seam to hold the two hemispheres together.

Glazing channel typically is made out of a relatively soft vinyl rubber. It is used around the edges of a single pane of glass before the glass is press fit into the aluminum frame of a sliding aluminum window. Metal corners are used to hold the corners of the aluminum frame together. Then it's common to use an awl or a nail punch to dimple the corners of the aluminum frame so they bite into the metal corners to hold the aluminum frame rigidly together.

Any place listed under "Window & Glass Repair" in your yellow pages phone directory will sell different kinds of glazing channel by the foot.

[sms]

Good idea. I've also seen "strip grommets" that would achieve the same thing .