Instructables

Step 2: Prepare the Ping Pong Balls

Drill a hole in each ping pong ball.

There are several ways to do this such as a drill, exacto knife, or by poking a hole in it with a nail. A nail is the quickest method, but you will need to spend more time later gluing the balls to the lights. With a clean hole just smaller than the bulb the ping pong ball will stay in place without needing glue.

To drill the hole in the ball you will need a drill bit that is slightly smaller than the Christmas light bulb. Approximately 3/16" should be good, but make sure to test fit a few before drilling the rest of the balls. You will need to prepare as many ping pong balls as you have lights, if it's a long string it probably has 100.

A quick note on drilling holes in ping pong balls:

The best method I found for putting holes in the ping pong balls uses a c-clamp, some paper towels, and a drill. First fold a 1.5" wide strip of paper towel over on itself several times so that it fits on the plates of the c-clamp and tape one on each side of the clamp. Next adjust the clamp so that it holds the ball just enough that it doesn't slip when you drill into it. Because of the give in the paper towel you can pull the ball out and press another one in without needing to readjust the clamp. If anyone finds a better method please share in the comments.

I found I got the cleanest hole by first pressing the bit against the ball so it depressed slightly, then running the drill at medium to high speed while applying light pressure. A drill press would be very helpful at this step, but is not necessary. As always, please exercise care when using power tools.
nickabc1233 years ago
soldering iron to make a small hole- emphasis on small- then using a drill bit about the same size as the light (drilling in reverse). you push the light through then pull to tighten. dont even need glue.
Great project.  I saw this somewhere else and we did a bunch of orange ones for Halloween.  Very cool glow on the front porch.

For drilling, I put the balls in an egg crate and just slid it around on the drill press work surface.  Worked great and I could just throw a handful into the crate and then dump them after drilling...no need for careful handling.
DON'T try to burn holes in them, leaves a disgusting scent that lingers for days.
We used a drill press and it worked great! Went through about 100 balls in 10 minutes or so :)
ali6665 years ago
Instead of a c clamp you could use Silicone Sealant, squeeze enough of it around a ball and cover it all the way up to around a few mills above the center line, allow to dry, or perhaps playdoh would work, anyways.. Nice intractable u got there.
willhooi5 years ago
alternaively, you can use a hot soldering iron to melt a small hole in the ping pong balls. beware of the fumes and molten plastic though..:)