Alcohol Powered Gun (Mini SpudGun)




About: Hi I'm Angelo! I am a college student taking my engineering majors in BS-EE/ BS-ECE at the DLSU. I use my course as an inspiration for making my current projects! I've been posting projects here ever since I...

Airsofts are to mainstream, so I made a pocket sized version of the SpudGun. It works like a spitball but has an ignition system. The gun shoots BBs, paper, tissue or any kind of projectile the would fits inside its the barrel. It can work as a mini BB shotgun, just simply load multiple BBs in the barrel and it shoots +4 BBs over 50 meters! 

How Does It Work:

It work when you put alcohol inside the chamber. In the combustion chamber, flammable materials gets ignited by the electric igniter (piezoelectric sparker), then when the gas or liquid gets burned it quickly creates a large amount of pressure inside the chamber, when the chamber gets pressurized the projectile exits the barrel at a very fast velocity. Since Alcohol is flammable and cheap I decided to use it. Different kinds of flammable gas or liquids can be used for better results.

Please dirseguard my grammar. I was 12 y/o when I posted this :DD

Step 1: Materials You Will Need

You Will Need:
- 2 Bottles
- Round Cylindrical Ballpen (BIC)
- Super Glue
- Lighter

Step 2: Getting Your Igniter

Open your lighter using a mini screwdriver. Insert your screwdriver in the metal part of the lighter and carefully remove the metal cover, then you will see a black object with a cylindrical metal below with a wire protruding, that.  will be your igniter for the spudgun. Be careful not to make a leak in the gas chamber.

Step 3: Saw the Bottle

Saw the top part of the bottle. Do the same with  the other bottle. You will need both of top part for your "Ignition Chamber". Be sure to make the cut very straight to avoid having leaks later. I recommend for you to use 2 same kinds of bottles for it to fit snuggly.

Step 4: Sanding the Top Part

Sand the top part with the roughest sanding paper then use the smoothest sanding paper in order to have a flat and smooth texture. After sanding be sure to clean both of it with soap and water. Be sure to remove the sanded plastic with water. Be sure to make it as flat and smooth as possible. 

Step 5: Glue Both of the Top Part

Glue both of the top part to make your ignition chamber. Be sure to apply enough glue for it not to leak. Escape of pressure in the Ignition Chamber reduces the projectile's range of fire. Leave the Ignition Chamber for about 2-8 hours for the glue to dry. Always be sure to make everything right and perfect. Efficiency is a huge factor.

Step 6: Punching Some Holes

Remove both of the bottle caps from the Ignition Chamber. Get the first bottle cap and make a hole for the ballpen enough to fit. Get the second bottle cap and make a small hole for the Igniter's wire and make another hole for the bottom part of the Igniter (cylindrical metal). Be sure to make every hole exact of its size. 

Step 7: Disassembling the Ballpen

Get a ballpen I prefer using BIC because its body is round and has a large diameter. Disassemble the pen then take the pen's body you will need it for your "Barrel". You can use a smaller pen for shooting smaller projectiles like seed or BBs.

Step 8: Making the Barrel Set

Get your first bottlecap with the single hole then attach the ballpen. Secure it by gluing it with hot glue. You can make differnet Barrel Sets for different kinds of ammo. Range depends on your barrel and ammo.

Step 9: Making the Ignition Set

Get your second bottle cap with the two hole cap. First insert the metal bottom of the Igniter then insert wire into the smaller hole. Secure the set by using hot glue.

Step 10: Assemble the Unit

Screw everything up. Check if there are leaks or any flaws. Make sure your glue is dry. Your project should look like this.

Step 11: How to Use It

How To Use It:

1st.) Unscrew the "Barrel Set"
2nd.) Fill it alcohol (2-5ml)
3rd.) Place your projectile below your barrel
4th.) Blow air for Carbon Dioxide to be replaced with air.
5th.) Screw it back again
6th.) Shake it two times

(See Video For Better Instructions)

Step 12: Aim It

Aim it at your target it should reach a distance for about 20-40 meters. Depends on your barrel and ammo.

Step 13: Tips


- You can make different barrel sets.
- Make your ammo fit into your barrel to increase efficiency with its mussel velocity.
- If your gun shoots very weak check for leaks or change your Barrel Set.
- Use Gatorade to have a larger Ignition Chamber.
- Use eye protection.
- Use denatured alcohol instead of Ethyl alcohol.
- Contact me at or just PM me here in instructables

Step 14: Here's a New Version of Mine - Looks Better and Looks More Like a Gun

This is my new version. I'm looking forward on making another Instructable about this 8/10/11 .



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    27 Discussions


    7 years ago on Introduction

    This is very cool, so I tried to build it, (with a planed modification to make it relode faster) but it wont ignite! I put alcohol in a PVC chamber, sparked it with an igniter from a cigarette lighter like you said, but it doesn't do a thing. I'm using 91% isoproply alcohol, which has always served me well in the past, and I know the igniter is working because it makes a big blue spark. Any ideas? Thanks for posting this! :D I hope I can get mine to work

    4 replies

    Reply 7 years ago on Introduction

    I guess you should change your Ingiter or maybe Just put enough alchohol. When I made my 1st version of this I can't even get it to work, I realized that the spark gap was to close :))


    Reply 7 years ago on Introduction

    YAY! I got it to work DESPITE homework :P You were right, it's all in the position of the spark plug :D


    Reply 6 months ago

    How long the spark gap?

    pie R []ed

    7 years ago on Introduction

    very nice. i find that with many bottles the inner diameter of the neck is the same as the outer diameter of 1/2 inch pvc pipe. if you want a larger chamber you can use the same setup you used here, but put the bottle pieces you used here over the ends of the pvc. just make sure it closes properly.

    1 reply
    ASCASpie R []ed

    Reply 7 years ago on Introduction

    I used gatorade but its to hazardous the barrel gets realy hot and you can feel the recoil of the gun. I've been so carfull of this project because I made a very large chamber with a small barrel so the energy released is very high although the ammo got stuck in the barrel so instead the ammo shoot the bottle cap exloded right into my eye luckily my dads an eye doctor i just got a small brius (black eye) :)))


    Question 4 months ago on Step 11

    Should we use sprit or nail remover instead of alcohol plz tell me or from where we can buy this alcohol in pakistan plz tell me


    Question 6 months ago on Step 14

    Gaano kalayo dapat ang wire ng ignator sa tatamaan nya ng spark?


    3 years ago

    very clear and well made steps


    3 years ago

    gonna add this to my favorites and nominate you if you put it into a competition!!!


    3 years ago

    epic stuff man im gonna make 1 of these now!!!!!!!!!!!!!!!!! thanks heaps for the idea


    4 years ago on Introduction

    This is amazing, especially considering your age! At your age, my parents wouldn't even dream of letting me do this!

    so you're a Filipino then. Me too! I'm 11 yrs old and likes to invent. i love guns(basically anything that shoots)
    I LIKE this!!!!

    1 reply

    Im a filipino too!......this is awesome invention....well...i prefer using ethyl alcohol (please correct if spelling is wrong) hehe when i tried with isoprophyl alcohol it wont work so i always use ethyl. it works well....thumbs up!....


    5 years ago

    where can you get this alcohol that you use

    the futurist

    6 years ago on Step 5

    first when you say blow do you mean down the barrel and second do i have to attach the metal part?