Mentos Diet Coke Rocket

By now just about everyone is familiar with the fun that can be had by mixing Mentos with Diet Coke. If you missed it, search YouTube.com or google videos for “mentos diet coke”. Below is some improved advice on how to do it properly. But also futher on you’ll find my own innovation for an even more impressive controlled Diet Coke and Mentos rocket.

Overview

Someone discovered that if you drop some mentos into a bottle of Diet Coke, all the carbonation will be released instantly.There are two basic applications, the Mentos Diet Coke Fountain and the Mentos Diet Coke Rocket. I went to Google Video and YouTube and watched all the videos people posted on the subject (hundreds). And I did a cursory search of web pages that give how-to and design advice. Most have very poor information. Almost all of the videos show only the simplest form of the ‘experiment’, dropping a handful of Mentos into Diet Coke, often with dissappointing results. I only found a few mentions of the rocket concept, but no good ideas on how to control it – which was fine because it meant that the coolest application needed some work…

Fountains

The best fountain advice I found was here:

I have only one thing to add to that advice. Caps from actual Diet Coke bottles are brittle and tend to shatter if you try to poke a hole in them. Drilling a 1/8″ to 1/4″ hole in a plastic cap is difficult. Instead, I used caps from WalMart water bottles which are the same size and less brittle. To make the holes I bought a set of decorative hole punches made for scrapbooking (shown to right). These are available at Micheals and JoAnns. They look like little staplers and come in various designs (circle, star, flower, spiral). The hole sizes were just right, the circle being 1/4″, and other shapes having less area. You can rip these punches apart and extract the ‘die’ – a piece of sharp metal of the proper shape. Then just place the die on top of a bottle cap (oriented opening down is fine), then hit it with a hammer to punch the hole. The star shape worked best.

The crown-effect fountain is extra cool, but I didn’t play with it for a couple reasons. Obviously it spreads the mess over a wide area. The remote firing concept from the above video helps but I still didn’t want my whole yard covered in soda. It also requires that holes be drilled or punched into the bottle after it is opened, but immediately prior to doing the fountain – you cannot prepare it in advance, and you can’t pour the soda into another prepared bottled without losing too much carbonation. A good solution to that would involve some kind of pre-drilled extended cap that you could screw onto the freshly opened bottle, but I didn’t work on that.

Rockets

I couldn’t locate a single example of the ‘rocket’ being done properly. All the videos showed people dropping mentos into the bottle, capping it, and slamming it into the ground hoping it would break just right and launch into the air – not reliable at all, and a huge mess, maybe even a minor hazard. Just plain not worth trying. Improvement ideas that people posted ranged from laughable to complex and expensive.

My final solution is very satisfactory. It’s simple, free, safer, predictable, and works just about every time. Click on the picture to the left for complete instructions. It’s very basic so it’s probably not a unique idea. But working it out, refining, testing, and documenting it was rewarding. I recently demonstrated this twice at a party and both flew 30 or 40 feet high without a hitch (sorry no video available here – you might be able to find it on http://www.happaymommay.blogspot.com/ July 2006).