Tennis Ball Mortar by Sonnimo1234


Introduction: Tennis Ball Mortar by Sonnimo1234

In this Instructable, you will learn how to make a fun and awesome Tennis Ball Mortar. Some supplies you will need are simple household objects, lighter fluid, and a regular tennis ball. I am not responsible for any injuries or damages to properties. I hope you have fun!!

Step 1: Supplies That You Will Need

For this Instructable, you will need.......
1. 3 cardboard tubes or cans approximately 10 inches long by 2 1\2 inches in diameter(potato chip cans work well)
2.tin snips
3.Duct tape or a strong type of tape
4.3\16-inch drill or punch
5.lighter fluid
6. tennis ball
7. wooden stick about 12 inches long
8.Thin walled, 4-inch diameter pvc sewer pipe( length equal to length of cardboard tubes or cans)
9. sand paper or sander

Step 2: Making the Tennis Ball Montar

In this step, we are going to make the Mortar:
1.Pick one empty tube or can to be the base tube.On the tube or can, drill a clean 3\16 hole about one inch from the bottom.
2.On the other two tubes or cans,puncture the bottom end with a tin snips so that you have one round-shaped hole in the bottom.
(baffles are the key to a good mortar, so make your baffles carefully.)
3.File or sand the cut holes to dull them so they are safe to handle
4.Assemble the three cans or tubes to the correct order.To put them together, cover the entire assembly with no more than three layers of duct tape or strong tape. Make the seams between the cans or tubes airtight.(Be sure to leave the firing hole clear and open.)
5.Now make a PVC blast tube out of the 4inch PVC pipe.The PVC tube should be made just as long enough to contain the entire Tennis Ball Mortar when slipped in. Drill a large hole in the blast PVC tube that equals to the location of the firing hole.

Step 3: Firing the Tennis Ball Montar

1.Use no more than 1\2 teaspoon of the lighter fluid.
2.Pour or drip the fluid down the muzzle(make sure some of the fluid gets the the bottom of the Mortar.)
3.Put the tennis Ball into the muzzle of the Mortar and take the wooden stick and press against the ball so it stays in place.
4.Shake the Mortar so it evenly spreads the fluid.
5.Move the Mortar to the firing position against rocks or trees
6.Take a lighter or a very long match and light it under the firing hole. It should fire after a few seconds.
NOTICE:The Mortar is very loud and should be done in a large field or area. Hope you have fun!!!!!



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    Any tips on what diameter to make the holes in the baffles?


    Doesn't work with hairspray - I followed the instructions to the letter, and the most I got was a "Whoomph!", a gout of flame, then nothing. The only thing that happened to my tennis ball was that it burnt.

    2 replies

    In our youth, we use a bamboo tube with 3 or 4 nodes. Made holes through all the nodes using an iron rod, a small hole at the side at the bottom to fire the fuel (used good old kerosene as fuel) . Same principle as the tennis ball mortar.This is used only for producing cracking sound. We had to experiment with different hole sizes to get the correct effect. Gives multiple cracking sounds. Now I assume that if we had stuffed a tennis ball inside the Bamboo tube ( which we never thought of), we could have had a tennis ball mortar.

    You need to make sure there is a FLUSH, SNUG fit.

    This is a HIGHLY ILLEGAL thing you're doing. You can be arrested for just CARRYING that...

    Hey, could you make an Instructable about it or just email me you plans (what ever you have time to give me) @ I seriously think you have something here and I'm also wanting to build it for selfdefence... that is, if the "US President" Obama takes away my guns!!!!

    you could duct tape like 5 of em together then run a fuse through all the base holes and make like a repeater

    1 reply

    im confused what do you mean run a fuse through all the base holes and then make a repeater? what do you mean by repeater also?

    Lighter fluid is just naptha, you can buy it by the quart or gallon in most paint stores. This is a lot cheaper then buying "lighter fluid" at a tobbaco shop. I learned how to make these using a six pack of steel beer cans, yeah I'm old in years but I have'nt quite grown up yet, I just graduated to bigger toys. We cut out the tops and bottoms of five cans and left the sixth one intact with a quarter inch hole in the bottom side. Taped it all together with electricians tape put just a squirt down the barrel jammed a tennis ball down two cans deep and lit it. Word to the wise NEVER hold your hand in front of the opening, the flame that comes out of there will cook your fingers right now.

    so technically a whole heap of cat food tins would work perfectly? cause i have alot of cats and go through a tin a day and they stack on their own adn the tennis ball fits with a minor gap but i was also wondering if it has to be lighter fluid cause i live in australia and don't know where to get it.

    3 replies

    where in australia are you? you can usually buy it from all tobacconists. Cignall usually has it. Paddy's markets in chinatown (sydney) has a few chinese ladies selling it. Beware though, one of the women down there that we were buying lighters and stuff from is insane. She'll burn you if you piss her off.

    well i live in brissie and im fifteen so they probly wont sell it to me even if i could find some. but metho or fero would work wouldn't they?

    haha i'm 16, and i went there most when i was 15. metho wouldn't work as an explosive, because it just burns. good fun to play with. but it does scar if you get burnt...

    Aussie! me and my friend used to crack open lighters and drip it on worms and ignite it if that would work (we were 7) (im Aussie to)

    this thing looks sweet, my friends and i are planning on building an extreme version and using about a cup of lighter fluid!!! hopefully we dont light our asses on fire! lol

    4 replies

    dont forget that wut ur making here is a bomb... so IF you are guna go crazy with the fuel, make sure the ammo isnt too secure or u will be lighting a pipe bomb not a mortar.

    that would be an interesting story...

    you'll need a large combustion chamber for the fluid to torn to gass to ignite. (its the lighter fluid vapour that lights, not the fluid its-self).

    Ok whats it means is to take a 1\2 teaspoon of lighter fluid and just drip it down into the tube you had you take a tennis ball and push it hard into the tube..finally with the tennis ball and the lighter fluid in the tube, carfully shake the tube so the light fluid is spread out equally...Thanks you for commenting:)

    1 reply

    hahaha, "push it hard into the tube" lol