Put some golf balls inside a Coke bottle!

This is a conversation piece that I made just for fun. It would make a great gift for the Coca-Cola and/or golf lover in your life . . . or for anyone that just likes funky, interesting things.

Read on to see how I did this, and the techniques you can use to put whatever you want into a Coke bottle as well.

Step 1: How Do You Do It?

There's no great trickery here; this was done just as you likely suspected:

The bottle was cut and glued back together with golf balls inside.

However, that's easier said than done . . .

All details are covered in the following steps.

If you're interested I've also made an "impossible bottle" instructable, where the bottles were not cut or modified in any way. It's a fun puzzle that pretty much anyone can tackle. Check it out here: Deck of Cards in a Bottle.

Step 2: Cutting Glass Bottles

Cutting glass bottles has been a DIY rage for the last few years, and there are a number tutorials and videos all over the internet that cover various techniques and contraptions people use to cut bottles.

My recommendation? Don't overthink it!

There are simple procedures you can use to get a clean break, which I'm outlining in this Instructable. Jigs and cutting fixtures are great if you need to cut a lot of bottles, but for the occasional one-off bottle project you can get by well-enough without.

Here's what you need:

Bottle (I used a 12 oz/355 ml Coke bottle)
Simple glass cutter
Basic oil
Sturdy stack of stuff as tall as you want to make the cut

Put some oil on the cutting wheel of your cutter, and hold it firmly down on the stack of stuff so it sticks out about 1 cm or so. I made my score line at the very bottom of the label band on the bottle, right in the crease.

Hold the bottle firmly against the table and press it against the cutting wheel. Rotate the bottle in a circle pressing it both firmly downward on the table, as well as against the cutting wheel.

You should hear a little grinding/crunching noise as you rotate, which indicates you are scoring the bottle as needed.

Score a complete circle around the whole bottle. You don't need to go over a scored area more than once! As long as you heard the crunching sound as you passed over an area, that area is adequately scored.

Step 3: Stress the Glass

The glass will break along the scored line if you stress it by exposing it to alternating hot and cold.

For consistently clean breaks, in my experience you don't want the "hot" to be too hot (blowtorch? NO!), or the "cold" to be too cold (ice? eh, not needed).

I've had the best results using running hot and cold water to stress the glass along the score. Using running water applies the most uniform temperature changes to the entire score line at once. (As opposed, say, to using a lighter and piece of ice.)

Here's what I do:

Turn sink faucet onto a small stream of the hottest tap water I can get, and take a pitcher of cold water from the fridge.
Start with the hot water. Rotate the bottle under the stream for about a minute, focusing the stream on the scored line.
Then, with the bottle laying in the sink, I pour a stream of the cold water onto the scored line rotating the bottle as before.
I go back and forth like this till the bottle parts along the score.

In this case, the bottle came cleanly apart immediately once I returned it to the hot water for the 2nd time. Be sure to either hold both sides of the bottle, or keep it laying in the sink so you don't drop the half that falls away.

Step 4: Viola!

Dry the two halves the the bottle carefully, as the cut edges are obviously very sharp.

(I know the word is not "viola." Everyone knows the correct spelling is "Wallah!")

Step 5: Add Marks

To make putting the halves back together easier once there's glue involved, I added a couple of dots on either half with a marker. I did this after cutting the bottle, but a better way would be to do this prior to cutting.

The seam appears especially visible in this photo, but after adding the adhesive it becomes slightly less obvious.

Step 6: Remove the Date Code

Just for looks, I removed the date code with a rag and some Goof Off.

Keep this stuff handy, as we'll be using it to clean up a tiny bit of glue residue later.

Step 7: Balls

Get some golf balls, and wash them if needed.

Step 8: Glue

For the adhesive in this application, I recommend E6000.

Alternately you could try some 2-part epoxy, but E6000 cures plenty strong, dries clear and is less likely to yellow over time.

Step 9: Add Balls and Glue

I applied a tiny amount of glue with a toothpick around just the outer half of the cut edges on both the top and bottom halves of the bottle.

I pressed the halves together using the marker dots as a guide, and gently wiggled the halves together until they seated themselves back in their original position. I let the bottle sit undisturbed for about 15 minutes.

Because of the way I applied the glue there was no squeeze-out internally, but a little externally. I used a rag and some more Goof Off solvent to gently wipe away the tiny bit of adhesive that had squeezed out along the joint.

Step 10: Add the Cap

I popped the original bottle cap back in place for looks.

Step 11: That's It!

A 355 ml bottle holds four golf balls, and a 500 ml bottle holds five.

Got any ideas of what else would be cool to see inside a Coke bottle? If you put something inside a bottle like this, I would love to see a photo in the comments.

Thoughts, questions, feedback are always welcome. Thanks for taking a look!