This Instructable shows you how to make a Zat Gun from Stargate. The only thing is that this won't stun anybody, and it doesn't fire that neat blue lightning bolt. Instead it works by igniting a flammable gas in an enclosed space. This enclosed space is the inside of a film canister.

DISCLAIMER:
If you hurt anything or blow your eye out it isn't my fault.

Step 1: Get Your Stuff

Here is a list of the materials you need:

Piezoelectric quartz igniter. I will show you how to get this from a cheep lighter.
PVC. I used a 1/2 inch diameter chunk about 20 inches long.
PVC end cap. This is for the end mount.
1/2 inch PVC end cap. This is for the but end of the 1/2 inch pipe.
Speaker wire. I used about 18 inches of solid speaker wire.
Electricians tape. You need lots, the more the merrier.
Solder.
Shrink Tubing.
Several film canisters and one film canister lid.
Sand. For bending the PVC.

Here are the tools you will need:

Soldering Iron.
Hot Air Gun. For the shrink tubing, matches will work also.
Gas Stove or Bunsen Burner. For bending the PVC.
Screwdriver. For gutting the lighter.
Wire Strippers/Cutters.
Hack Saw. For cutting PVC
Drill. For drilling out the larger PVC end cap.
Epoxy. For gluing on the larger end cap.

Step 2: Gutting Your Lighter

Now you need to get the igniter. This is the most important part. Thankfully this part is easy to get. Almost all lighter will work, just make sure that the lighter is not one that uses a flint striker. Now all lighters are built a little different but here is how I took mine apart.

Slip the round black ring up the metal tube.
Unscrew any screws that you can find. My lighter has two but some only have one.
Cut the sticker along the joint between the two haves. Some lighters don't have a sticker here.
Break the two halves apart, and pick up all the pieces that fly all over the house.

Now you should have the following:

Igniter. This is the part we want.
Butane tank and hose. Save this it might be useful for something.
Everything else is trash.

You should wrap electricians tape around the center of the igniter for reinforcement.

Step 3: Bend Your PVC

This is probably the hardest part. Please use this tutorial to bend your pipe:

https://www.instructables.com/id/Bend-PVC-Pipe/

You can bend it however you want, but I would suggest that you look at several pictures so that you get it just right. I used a Bunsen burner but you could also use a gas stove. I tried to use a normal propane torch but it burned the pipe to easily.

Step 4: Mounting the Igniter

The next step is mounting the quartz igniter. The wires that are connected to the igniter won't be long enough so you need to add some wire to them. I used about 18 inches of solid speaker wire. I used this because It was the cheapest solid wire that I could find. You need solid wire because it will make it easier to make the spark gap.

Here is what you need to do:

You need to lengthen the wires on your igniter. The wire, on my igniter, is solid and needs to have another wire soldered onto it. However, the red wire can be removed and replaced with a longer wire. This wire is held on by a small rubber cap you can just slip the cap of and replace the wire. Don't forget to insulate all joints with shrink tubing.
You now need to drill three holes. Two of these will only go through one wall of the pipe but the other one will go all the way through. The first hole is for the igniter, figure out where you want the trigger (igniter) to be. Once you figure out where you want it drill a hole through one side of the pipe. This hole needs to be big enough for the igniter, but you don't want it to be to big or your trigger will be loose.
You now need to drill a hole all the way through the pipe. This hole should be just before the first bend. This hole should be about an 1/8 inch in diameter, or just large enough for your wires.
Now run your wires up to just before the second bend.
Now just past the second bend you need to drill the last hole. This hole will only go through one wall of the pipe. This hole should be the same size as the last one.
Now run the wires out the end of the pipe and your dine with this step.

Step 5: Making the Spark Gap and Mount

The next step is to make the spark gap and spark gap mount. To do this we are going to use a PVC end cap. You can use any size you want but it is best to use the size that will hold the film canister lid the best. I used a 1.5 inch end cap.

The first step is to drill a hole in the end cap. This hole should be the same size as the outside diameter of your 1/2 inch PVC.
Slip the 1/2 inch PVC through the hole you just drilled in the end cap. You don't want the 1/2 inch pipe to stick out past the end cap, so you probably only need to push it in 1 to 2 inches.
Now you need to fill the space between the pipe and the inside of the end cap. If you don't do this the film canister will not sit on the end well. I filled mine with glue and wooden dowels, but you could fill yours however you want.
Once you have filled the gaps and made a good solid mount you need to attach the film canister lid. To do this you need to start by drilling a hole in the center of the lid. This hole should be big enough for the wires, but no bigger. Now you need to attach the film canister lid. First slip the wires through the hole, and then glue the cap to the head. The glue won't be enough alone, so put a small tie down strap around the wire and tighten it all you can. The idea of the tie down strap is that it will be larger than the hole and the film canister lid won't be able to slip off. Once the tie down strap is in place you may want to glue around it.
Now all you have to do is make the spark gap. This spark gap is just like the one on a engine, except that because the igniter generates a higher voltage the gap is larger than that of an engine. trim the wires so that they are only about 3/4 of an inch long. Now strip the first 1/4 inch of each one. Then bend the wires so the stripped ends are about 1/4 to 1/2 inch apart, The distance varies upon the igniter, so you should experiment.

Step 6: Finishing Up

Now we have just a couple more things to do. You need to cover the wires and PVC with electricians tape. This is done to make it look nicer and to protect the wires. Put the 1/2 inch PVC end cap on the but end, you can glue it if you want. Now your zat gun is done and you are ready to test it.

Step 7: Firing

Here are the steps for firing:

Push igniter to make sure you have a spark.
Now take the film canister and spray your fuel into it, quickly snap it onto the gun. Make sure you don't mess up your spark gap while doing this.
Point the gun at the target and fire the igniter.

Now the bad thing about this is that it doesn't work very well in colder temperatures it works best if the air temperature is above 75 degrees.

Step 8: What to Use for Fuel

The following things will work for fuel:

Binaca breath freshener.
Rubbing alcohol. I have used 70% isopropyl alcohol, 91% isopropyl alcohol, and 70% ethyl alcohol.
Hairspray. If you can find some with a volatile propellent.
Antifreeze. Antifreeze is largely methyl alcohol.

You can experiment with using different flammable liquids and gasses. But don't try anything really explosive like high octane gas.

Step 9: Science

The science behind this project is just like that of an engine. In this a spark ignites a mixture of fuel and air inside the film canister. this creates an explosion that forces the film canister off of its lid. This is the same reaction as in an engine, except that in an engine the explosion drives a piston instead of firing something through the air.

The other part of this that is scientifically interesting is the igniter. The igniter works by hitting a piece of piezoelectric material very hard. Piezoelectric materials have two special characteristics. The first property is that if you apply a high frequency voltage to them they vibrate causing a high frequency noise. One of these is probably what is in your alarm clock. The other property, the one that is used in this, is that when they are hit they create a burst of high voltage. This burst is what causes the spark.

Here is a neat video about piezoelectric crystals:

http://hackaday.com/2011/03/15/cooking-up-piezo-crystals-at-home/

I hope everybody likes this instructable. If you have any advise or comments please post in the comments section.