How To Build A Big Spudgun

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When you are done with the basic spudgun and crave something more exciting, it is time to build the Big One. Measuring about 12 feet long, this spud chucker is sure to impress. I have not yet measured the total distance that this can fire because of space limitations, but it definately blows the basic spudgun away.


You may want to use PVC pipe. That is fine. Just remember to get the right type of glue and primer. Personnally, I think that PVC is more brittle and weaker then ABS, plus it takes more time to glue. Because of this, I recommend ABS over PVC.


Step 1:
Assemble the T section. Glue one of the sections of 4 inch pipe to one of the branches of the T. To do this, spread glue on the joints of the pipe and T, then push the parts together and give them a slight twist.

Assembling the T

Step 2:
Prepare and attach the 3 inch pipe. Glue the 4 to 3 inch reducer to one end of the 3 inch. Now glue the 3" to 1.5" reducer to the other end and glue the female part of the 1.5" threaded adapter to the 1.5" section of the reducer. Then, glue the reducer to the piece of 4 inch that is attached to the T.

Attaching the reducer Attaching the 3 inch

Step 3:
Prepare and attach the other section of 4 inch. Glue the end cap to the other section of 4 inch. Now glue that to the remaining branch of the T. Do not use a test cap!

Installing the end cap Installing the caped 4 inch

Step 4:
Prepare the barrel. Sharpen one end of a section of 1 1/2 inch. This will automatically cut the spud to size when it is loaded. Next, glue the 1 1/2 inch coupling to the non sharpened end of the 1 1/2 inch pipe. Note that this coupling is not needed when using one section of 1 1/2 inch. Now, glue the other section of 1 1/2 inch to the other end of the coupler. Again, this is not necessary when using one piece of 1 1/2 inch. Glue the non sharpened end of this now longer pipe to the male part of the screw in adapter. Before you do this, remember to seperate the male and female parts (stop laughing).

Installing the coupler Connecting the pipes Installing the male screw in adapter

Step 5:
Attach the handle to the cleanout plug. Bolt the angel iron to the top of the cleanout plug. Use a washer and lock washer on each side.

Attaching the handle

Step 5:
Install the electrodes. Drill two holes and install the two three inch bolts so that there is about a 1/4 inch gap between them inside the pipe. This is where your ignition spark will jump accross. You should be able to adjust that distance by turning the bolts.

Installing the electrodes

Step 6:
Install the BBQ igniter. Connect a wire to one of the bolts. You can solder it, or just wrap it around a few times. Obviousely, soldering provides a better connection. Attach another wire to the other bolt. Attach one wire to the BBQ igniter. The wire usually plugs or gets soldered onto a small metal tab on the side of the igniter. Now, attach what will become the high voltage lead. This almost always connects to a small recessed post on the bottom of the igniter. Tape (or glue...) the igniter to a convienent spot on the T. You will need to be able to easly push this in order to fire the gun. Note that for this gun I very highly reccommend using a high voltage generator to supply the ignition spark. See the mods section.

Step 7:
Watch the glue dry. The glue needs 24 hours to dry completely, so you will have to wait at least that long before you can fire the gun. Do not attempt to shoot the spudgun unless the glue is dry or it could blow up. Trust me, I know from experience.

The completed spudgun


To fire this biggun', I would suggest you have two people. One presses the igniter, while the other one holds the middle of the barrel and aims.

1. Open the cleanout plug. Shove a good sized potato down the 1 1/2 inch pipe until it reaches the 1 1/2 inch to 3 inch adapter. You will need something to ram the spud down the pipe. I use an old tent pole with a rubber tip on it.

2. Squirt a bit of deoderant into the T. A four or five second blast usually works. For optimum performance, use butane. Or, even better, use a mixture of liquid oxygen and propane.

3. Aim the spudgun away from other people and press the BBQ igniter. If all is well, you should hear a very loud bang and feel the recoil.

4. Congratulations. You now have a working, and really big, spudgun.

If you have any suggestions as to how I can improve these plans, don't hesitate to mail me.

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