This instructable will show you how to make your own bottle rockets using Visco fuse as propellant. Visco can be purchased at many online stores. I buy mine from the local firework wholesale shop. I am not taking any credit for this design, I have just modified it. The changes I've made have been mostly weight reduction. I have made changes to the bamboo skewer, the crimping method, the crimper spacer, and the amount of computer paper used. In my first test, I noticed that the rocket did not shoot straight up but off to the side. This could have been due to a few different reasons but when I reduced the overall weight and crimped it a certain way, it seemed to fix it. This was also posted at skylighter.com as well and originated from a book written by Lancaster.

***Just a quick side note: I do not take any responsibility for your actions while constructing this firework, or any others presented to you, by myself. ***

Step 1: Gather the Required Materials

You will need:
(1) Hot Glue Gun
(1) Drill with 1/8 inch bit
(1) 1 in X 3 in strip of masking tape
(1) Glue Stick
(1) 2.5 in length of Visco Fuse
(6) 1 in lengths of Visco Fuse
(1) 1.75 in X 5 in strip of computer printer paper
(1) Ballpoint pen **Make sure it has a slightly rounded end
(1) Length of twine or string
(1) Bamboo Skewer
(1) Pair of scissors

Optional:
Various powdered metals, such as Zinc, Aluminum, or Titanium

Step 2: Making the Crimping Spacer

The crimping spacer will allow you to crimp the nozzles of these rockets a whole lot easier. The original design was published in a newsletter from skylighter.com and used a wooden dowel rod. I did not have a dowel rod handy and decided a pen would work great.
First, start off by measuring 1 inch from the end of the pen and cut it off. Next, drill a 1/8 inch hole into the end and make sure the fuse fits in nice and smooth. Lastly, wrap some tape 3/8 of an inch down from the end cap until it is about 1/4 inch thick.

Step 3: Rolling the Engine

Start off by laying your 3 inch long piece of masking tape down on a smooth surface, sticky side up. Lay the long piece of Visco fuse 1/4 inch from the bottom followed by all six of the small pieces. Before you roll it up you can add some metal shavings or powder to color the tail of your rocket, but it's only optional. Start from the bottom and roll it up as tightly as you can. You want to get the long fuse in the middle surrounded by the six smaller fuses. Usually, you will have to reposition the longer fuse to get it just right. After you have it all rolled up, lay down your computer paper strip and cover it with your glue stick. Place your fuse package about 1/4 inch from the top. I use my crimping spacer to make sure I have enough room for the crimp; about 1/4 inch as well. Roll it all the way up and squirt a bit of hot glue on the top to seal it. You have to make sure you have no holes for the pressure to escape but also keeping in mind that you do not want too much glue, as it will weigh down your rocket.

Step 4: Crimping

This step is key. If the crimp is not tight enough or is not correctly done, the rocket will just burn. It may be a bit complicated but after you do one and see what I'm talking about, it should come easier. Start off by inserting your crimping spacer, feeding the fuse through the hole, until the masking tape stops it from entering any further. Next feel around for the space that is created between your spacer and the bottom of your fuses and work it around and squeeze it. You want to make it weaker than the rest of the tube so it will fold easily. Now firmly grip the top of the rocket with one hand and the spacer with the other. Slowly twist and push until the paper folds down nicely. To finish it off, tie a knot around it with your string to keep it from unfolding.

Step 5: Attaching the Guide

For this you will need a bamboo skewer. In order to reduce the weight of the rocket, we are going to cut the skewer in half as shown. Smear a bit of hot glue on one end and stick it to your rocket. And that's it! Your Finished! I have yet to experiment with payloads and such but I assume that you would be able to put a firecracker on top of there. I'll post anything regarding payloads as I fool around with it.

I've included two videos, one with zinc fillings and the other with aluminum. They look pretty much identical to me though :/

Zinc