Impossible Metal Ring Through Coke Bottle




About: I got an old sewing machine when I was just a kid, and I've been hooked on making stuff ever since. My name is Sam and I'm a community manager here at Instructables.

This is what's called an "Impossible Object."

These types of objects are not literally impossible of course, as they are all created somehow.

These things are tangible illusions that can be held and inspected up close. They seem to defy logic and appear "impossible." They are great for gifts and are intriguing conversation pieces, and provide an interesting challenge to make.

The item I've made here is a solid metal 1/4" thick ring through two holes in the neck of a coke bottle. There are no visible seams on either the bottle or the ring.

Step 1: Video

This was inspired by a great project shared by Jack Houweling on youtube where he puts a wooden ring through a Coke bottle: Impossible ring through glass bottle.

I wondered how hard it would be to create basically the same thing but with a metal ring instead of wood.

Metal is less deceiving than wood grain however . . . so while this isn't quite as cool as Jack's wood version, I thought it was a neat thing to make and have.

I made a video of the creation process. Check it out if you're interested:

Step 2: What You Need

Here are the materials used for this project:

  • glass Coca Cola bottle
  • 2 1/2" zinc-plated metal ring, 1/4" thickness

Tools required:

  • glass cutting bits (I have this set and used the 5/16" bit)
  • diamond grinding burrs (I have this set)
  • carbide grinding burrs (like these)
  • rotary tool (I've had this for over 10 years, and despite the abuse it keeps going strong. Black & Decker . . who knew?)
  • drill press, clamps
  • sandpaper
  • metal polish (I used this)

The basics of my welding setup:

For cutting the metal ring I used:

If you're new to welding I strongly recommend this excellent welding class right here on Instructables: Welding Class

Step 3: De-zinc the Ring

The first thing I did was put the zinc-plated ring in vinegar until the plating was completely dissolved.

This is important because while you can technically weld through the plating, it will release a toxic gas that is extremely hazardous.

So this is the easiest way to make common hardware items like this safe to weld.

I bought this ring at a local hardware store. They also had nickel-plated rings, which have a more shiny and almost yellowy-tint, but that plating cannot be dissolved in vinegar. The general rule of thumb is to never weld through platings. So what you can't safely dissolve, you should grind off down to bare metal.

Step 4: Drill Holes in Bottle

The bottle cap was very gently pried up from multiple points to remove it without deforming it. This way we can pop it back on later. Then I drank the Coke.

I set up a board on my drill press to which I clamped the Coke bottle.

The board was clamped to my drill press table, and a spray bottle was used to keep the drilling area wet.

The drill was set at a lower speed and two holes were made in the top of the neck of the bottle using a 5/16" glass drilling bit.

You have to go fairly slow and let the drill bit remove just a little at a time.

Step 5: Cut Ring

The metal ring was cut in two using a portable bandsaw.

Step 6: Embiggen Holes in Bottle Neck

I used a diamond burr in my rotary tool to grind the inside edges of the holes in the bottle, so the ring could pass freely and spin up and down without getting stuck.

This was done with frequent mists of water on the holes from the spray bottle.

Step 7: Weld the Ring

The ring halves were propped into position on my metal welding table, with one half going through the bottle holes.

The ring was then welded back together with several small spot-welds all around both joints.

Step 8: Grind the Ring

Using a carbide burr in my rotary tool, I carefully ground down the welds to match the ring shape as best I could.

I then ground all around the ring and intentionally went a little rough on it to give the whole thing a fairly worn and abused look. This worked to make the two welded/ground areas blend in and basically disappear.

Step 9: Polish the Ring

Some automotive metal polish was used with a couple of rags to quickly polish and buff the metal ring by hand.

Step 10: Wash Bottle Out and Replace the Cap

The bottle needed a good washing inside and out. I shoved some bits of cloth into the inside and swabbed them around with a thin metal rod to get the inside clean. These bits were then plucked back out with tweezers.

The cap was replaced and that was it!

Now it's up on a shelf with my other oddities and homemade "Impossible Objects" waiting for people to examine it and say "wait a second . . how did you . . ?"

Thanks for reading! : )



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    16 Discussions


    8 months ago on Step 10

    Love it. But I would wash it before I made the hole. And an easy way to wash without having to stuff cloth in is to fill half full with hot soapy water and eggshells. Shake it up, dump it out and rinse. The eggshells act as an abrasive to remove stuck on stuff, and are biodegradable.

    1 reply

    Reply 8 months ago

    The eggshells are a great idea, thank you! At the end of the whole process, the bottle ends up pretty dirty - from the hole drilling, the welding residue and grinding debris. This is why I washed the bottle after. Thanks for reading and commenting!!


    8 months ago

    Nice job. I love your impossible projects!

    1 reply

    This was a awesome project. It is so odd to look at because you just wonder how the ring got there.


    9 months ago

    Great. This solved my issue. I wanted to hang some vintage soda bottles with LED's inside of them. This is a brilliant way to hang them.

    3 replies

    Reply 9 months ago

    Thanks! Although you might want to use those two-part snap rings rather than have to weld. Unless you want to weld them! : )


    Reply 9 months ago

    Thanks. I really DON"T want to weld nor do I know how. What is a two part snap ring? Not a circlip? I suppose even beaded chain would work, but I love the look of your ring.


    Reply 9 months ago

    Ah, I wasn't sure what to call them. I was picturing these things:

    Those would be quick and easy for hanging drilled soda bottles. Or even just bent wire, really. Lots of options I'd think.. but I love the idea of hanging old soda bottles with LEDs in them. That will look really slick!


    9 months ago


    It is done.

    Tura Street

    9 months ago

    This is really cool. Thanks so much for the great idea, and thanks for sharing.

    The other Finnish guy

    Tip 9 months ago

    If you rust the ring its even harder to notice sand / weld areas. That could be done with electrolysis or acid. Or just dipping to salt water and drying with flame, dip, dry, dip dry... i used that for making stand for my axe. Great hack, i was just thinking..


    9 months ago

    Have the same welder! I just hold my breath when I weld anything small with plating. Also read that using a fan nearby helps to move away any bad fumes.

    Cool project!!!

    1 reply

    Reply 9 months ago

    Thanks! It's been a great welder, I've been having a lot of fun making stuff with it. Thanks for checking out my project : )


    9 months ago

    I first thought it was solder or some type of soft metal that was cut (once), bent and inserted into the bottle holes, and then bent back and brazed. I think it might be even better if you left it in water for a week and let the ring rust completely. Then it might be less obvious to people that it was cut and welded (not saying that it's obvious, just harder to guess)

    Also put a bit of tape on the bottle opening and then you don't have to clean it! :)

    I like these impossible projects!

    1 reply

    Reply 9 months ago

    Hey, thank you! I'm glad you enjoy them - I think they're so much fun.

    Excellent tips! I should let the ring get rusty for sure. I will put it in water right now :)