This is why potato cannons are dangerous.
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- čas přidán 15. 05. 2024
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When I went out to visit Paul Gregg, backyard PVC rollercoaster extraordinaire, he showed me his extensive test results of PVC fracture toughness. He found that PVC lost something like 50% of toughness after a year of daily sunlight (UV exposure causes the plastic to become harder and much more brittle), but painted PVC in the same conditions retained over 98% of the same fracture toughness it started with. Color and type of paint made little difference. From then on I've been painting all my PVC projects.
Well, that makes sense. I'm gonna paint my outdoor pipes.
So it's suntan lotion for PVC lol
Cooll
Can't wait for your next upload
What type of paint? UV resistent acrylic paint?
Make videos bro
Babe wake up the backyard scientist just posted
@Don't Read My Profile Photo L
@Don't Read My Profile Photo ok
And he has POTATO CANNONS!
Let's gooooooo!!!!!!
@Don't Read My Profile Photo ok
My brother’s friend is a steamfitter and he welded a potato cannon out of steel pipe. I believe it was fueled with acetylene and oxygen. It was big and heavy and had its own stand. It launched potatoes out of sight (likely into orbit) with a tremendous bang. Good times.
I'd love to have one of those.
I love this!
Classic combo of gasses, great for old fashioned welding
Bring out the tater 8 pounder! tally ho lads!
So, it was the size of a Saturn 5 rocket? The potato cannon?
To get into orbit it would have to reach escape velocity. Which is 6 miles a second or roughly 25,000mph.
I'm sorry, did this man take a Bong hit through a potato cannon? Legend
I laughed for a good 10 minutes at that
I just started the video and haven't gotten past this spot. I was like omg. I came here for this comment.
@@lucivarsadiablo4191 happy to provide
I thought I was going crazy does he usually do stuff like that lol
lol that was funny
I had never seen pressure-rated PVC pipe in hardware stores here in the UK, so once, many years ago (like probably 2003 or so) when we were on holiday in Florida, we filled a whole suitcase with assorted fittings and got a couple of 6 foot lengths of pipe back as hold luggage. The guys at the airport didn't know what the hell to make of it 🤣🤣
Damn plumbing enthusiasts with their product samples.
Wow that is a genuinely amusing story lmao
I imagine the TSA dude's just thinking "none of this is actually against the rules, but I really don't want it on the plane..."
Sorry sir but we are going to confiscate your Spud Gun parts. They have no serial numbers on them.
Same in ireland
Love how the blast shield is basically just a -sheet of plywood- small metal plate they have to crouch behind. Love it.
That's not plywood it's a metal plate.
@@FearThePegasus *inflates you, making you big and round*
how did you cross that out??
@@johnyray6801 ˙ɔıƃɐɯ
@@ChrisD__ *detaches argon hose* Not today bud
I built a PVC potato cannon many years ago only I used water balloons instead of potatoes. The power, range, and thudding BOOM when I shot the thing were most gratifying. I started off with Aqua-net hairspray but later found that old-school Right Guard deodorant in the brown spray can was much cleaner burning, much more powerful, and left a nice fresh scent! BTW: a cup of paint balls was pretty amazing too. I called it the shotgun of Moses. The paint ball pattern was murder out to 100 feet or so.
you used deoderant as fuel?? was it powerful enough to break concret (or bones?)
I don't think it will break concrete. I did break a wooden privacy fence. It also punched a hole in a plastic dog house one time. I certainly wouldn't shoot it at a person or a pet. Not at a car or a house either. It could easily break a window.@@-jank-willson
if you made one, but used a much smaller diameter pipe, that was too small for potatoes, but just the right size for ball bearings, do you think it would 'end' somebody? AKA a homemade firearm?@@fecklesstech929
I did see a video where somebody broke a concrete slab with a potato launched from one of these. and also put molotovs in it instead of potatoes...
@@fecklesstech929
I've been making quality potato cannons for years. Only time I've ever had a problem was when I went on vacation and my roommate decided to put a mortar firework into my newest build that had a 3" pipe for the combustion chamber tapered down to a 2" for the barrel. Firework obviously got stuck in the chamber and exploded in his hands.
I was very surprised that he was surprised that it shattered on him.
make way, mr brain is coming in
How do you make a potato cannon? Or what defines a potato cannon and what are some do's and don'ts when trying to make one, sorry if I'm asking much
He stoopeed
so youre good at making potato cannons, so a specific question. can i make a 29" barrel with a 2" diameter with a 5" long chamber 3" diameter? possibly 4" but taper it? trying to make it resemble an at4 for halloween lol
Does your roommate just randomly play with your things, trying on your used condoms???
the way how he looked at the price of a bombsuit (30k) then looked at the camera before it cut to a sponsor is hilarious.
I was about to say that as well, but hey, you could probably label it as a business expense right?
Made me laugh ngl
Too funny
now that's how you transition to an ad
too bad Honey is kinda a scam.
Building them with my dad as a kid, we always had cut a "duct tape safety" in the rear chamber. If the pressure was too high, it would blow the back off, and remain dangerous directionally (forward and rear) rather than omnidirectionally. He only ever blew the safety when he used acetylene, rather than his usual starter fluid.
I never did go back and make a new one when I became an adult, but I wanted to try to build a pneumatic spudgun with an electric solenoid. The pressure can be higher and more consistent, so it's safer than guessing how much starter fluid you used.
What kind of potato gun? Was it compressed air or propane or was it hairspray. Because I imagine a hairspray potato gun would be far safer because pushing a potato out a barrel is far easier than blowing up outwards.
@@BenMyhillJones we usually used starter fluid. Hairspray was ok.
Pneumatic would provide a more consistent power, so your safety margins could be higher
@Don't Read My Profile Photo ok
Did you say acetylene?!
We would wrap ours in bailing wire and/or fiberglass. Never had an RUD.
PVC is transparent to X-rays also if I recall correctly. So the only way to find all the shrapnel in you is through exploratory surgery. Yup, they just gotta dig til they hopefully find it all.
I made one many years ago out of copper pipe with an mip on the rear and a threaded pvc cap. The cap was the weak point so any failure would be controlled and directed in a safer direction. It worked really well with aquanet. Also, I sharpened the end of the barrel so it would trim the potato to tight fit as you pushed it in.
Jesus what size pipe did you use. 2 inch copper is 30 bucks a foot, 3in 60, and 4in 90 where i live
@@user-cb1ln8vc8d 2" barrel 4" combustion chamber. It was 25 years ago, copper was cheaper back then, but I still don't pay anywhere near $30 per foot for 2" type l.
Sensible chuckle: Cutting from a 30k price tag for a suit straight to an ad was one of the best transitions I've seen! Props to the editor/timeline decision maker!
I UNDERSTAND THAT THERE ARE A LOT OF COMMENTS HERE, BUT PLEASE READ IT !
I also try to create interesting content (experiments). Will you write your opinion? dg
Personally what I would do to secure it is have a loose layer of thick canvas around the cannon and then 2 offset layers of hardware cloth on top of that. I think having something loose around it would be more effective than something tightly hugging it like fiberglass or duct tape because it would give the PVC room to rupture and release the gas inside while still catching the shrapnel.
This is what they do with cevlar jackets around drive shafts /gear boxes at racing
I would never use any type of PVC at all for any DIY pressure stuff, especially close to you. One of the reasons we use HDPE for fireworks tubes...aside from a decent pressure rating...when it fails, it bulges, stretches, and then shreds.
Dunno; thats kinda what he did and the glass fiber didnt do a very good job of containing the shrapnell. In any case, such a design including the one used here wouldnt improve max pressure; infact the concentrated loads induced by the chicken wire risk substantially weakening the PVC as it gets stretched outward onto the discontinuous metal wire. Pulling a kevlar continuously braided sleeve, or maybe something like UHMWPE (though i dont know thats readily available as sleeve), would provide orders of magnitude more impact toughness than glass, for sure, and if the kevlar is epoxied on, it will provide a crapton of strength and stiffness too, so you can make it so it only blows out the ends and will be safe to hold.
Works good for hydraulic hoses with tiny wire shrapnel. It's usually nylon webbing.
Just go with a larger PVC pipe outside the one you're pressurizing...
Before PVC, we used empty tin cans, before they punched them from Aluminum. Taped together, built right, they'd send a tennis ball quite a distance on just lighter fluid. I was in the Air Force, couldn't keep it together, but in a box, with a few cut up to make model airplane tanks, the others could be taped together in minutes, fired to wake everyone up, and tear it down in seconds and look just as surprised as anyone.
Though Illegal, its very papular on the Philippines to celebrate new years though various degrees of safety and quality.
Ahhhhh 1972 again!
@@rdm5190 Oh to be 21 again. I wake up feeling twenty-five, look in the mirror, to shave, that reflection tells me no, I'm not 25 anymore.
This is why you should make designated failure points. Something like a plug glued in so if the pressure gets too high it shoots out instead of exploding. The idea is that if it's going to break it'll break in a predictable manner that can planned around and made safe.
This is really common in things like water pumps for trains. They have exactly this though the plugs are screwed not glued into place.
I've built half a dozen cannons over the years, always using ABS cellcore, and using butane as the fuel. Never had any of them go catastrophic, even after loading heavy projectiles and abusing the crap outta them. This plastic behaves differently from PVC, particularly when it comes to firing in the wintertime. If you live in a cold climate, never use PVC.
My ABS cannon is 18+ years old.
We used to use hairspray on the cannons we built in high school in the 90s
@@djhaloeight I didn't like hairspray as it gummed everything up. I had good success with a generic Dollar Store version of Right Guard deodorant.
Yeah, I have multiple 10 plus year old cannons. Never used PVC. I use aqua net hair spray and some heavy and tight fiting objects. Never had a failure
@@minter_fab_mafia Walnuts right off the tree with their husks still on will kill a deer. At least that's what I hear.
Second degree burns on my eyelids…I built a potato cannon when I was in high school. Glued all the pieces together and left it over night to cure. The next morning, I hooked up the sparker and looked into the combustion chamber to make sure the leads were close enough to spark. They were. And they ignited all the PVC cement fumes that were still hanging out. The fireball gave me second degree burns on my eye lids. I still have no idea how I was able to close my eyes in time. Careful out there, kids
Thankfully, the blinking reflex is the fastes reflex we have. Eyes are precious.
Yea. I didnt use fire, just air.
I didnt use PVC primer with my first. I had it around 100 psi or so when the front barrel blew off. Threw the ~1kg barrel around 10 meters or so in front of me. The air chamber shot backwards and gave my arm a good cut. I still have that scar, and this was 3 or so summers ago
I'm hella lucky I didnt get hurt more
Thank god you can still see
I did the exact same thing when I built my first one
@@bagelsgarage seriously? Haha glue fumes are the hidden killer
Love your energy man, great videos!
I just got to say i love that transition into the ad, Showing the suit for 29k, your smug face and then BAM, Ad time! Great work man i love your channel!
I was the pressure tester for a company for 2 years. Aluminum tanks with fiberglass and resin covered, used for air/oxygen tanks by Firemen also large tanks for Vans using natural gas also COTA bus natural gas tanks. They almost 6 ft. long and 2.5 ft. diameter. The firemen O2 tanks would blow at 14-20 thousand pounds. They had to fail at the ends also. But of course pop off valves were used when built. Also did fire bomb tests and projectile tests from 30.06. Great job. All was done in a concrete safe and also inside of a metal tube with end caps. The man before me was killed when one blew up wrong, took the safe room door off and hit him. We always crouched down behind the machine on failure tests. D.O.T. was always there watching explosions, recording all findings. All was graphed out on chart paper for reference. Yes we used compressed water thru very thick stainless steel pipe. Each lot of 200 tanks, two were used to test. Testing would used pressure pumps, hydraulics to pump them to 5000 psi over 30 sec. then down to zero over 30 seconds. Then after 10,000 cycles then the pressure went to 7500 psi 30 times, then it went to failure in a concrete reinforced room. Every different size tank had differing pressures. Larger the tank, smaller the pressures.
Ever have any close calls yourself?
Yeah... should I be worried about putting 4500psi carbon fiber tanks on my face while shooting my rifle? (Also have a 3000psi aluminum)
4th of July every work day want more could you ask for? Bring you Kid to work day. Where do you work now?
Pick up your cross and follow Jesus! The world is quickly headed for destruction, and sooner or later you will have to sit at the judgement seat and give an account for your actions. Belief in messiah alone is not enough to grant you salvation - Matthew 7:21-23, John 3:3, John 3:36 (ESV is the best translation for John 3:36). Call on the name of Jesus and pray for Him to intervene in your life! - Revelation 3:20.
Contemplate how the Roman Empire fulfilled the role of the beast from the sea in Revelation 13. Revelation 17 confirms that it is in fact Rome. From this we can conclude that A) Jesus is the Son of God and can predict the future or make it happen, B) The world leaders/nations/governments etc have been conspiring together for the last 3000+ years going back to Babylon and before, C) History as we know it is fake. You don't really need to speculate once you start a relationship with God tho.
Can't get a response from God? Fasting can help increase your perception and prayer can help initiate events. God will ignore you if your prayer does not align with His purpose (James 4:3) or if you are approaching Him when "unclean" (Isaiah 1:15, Isaiah 59:2, Micah 3:4). Stop eating food sacrificed to idols (McDonald's, Wendy's etc) stop glorifying yourself on social media or making other images of yourself (Second Commandment), stop gossiping about other people, stop watching obscene content etc and you should get a response. Have a blessed day!
Compressed water? I thought water was incompressable
I have been involved in a failed compressed air fuelled acorn canon incident and it wasn't fun. Couldn't hear anything in one ear for an hour or so and couldn't feel one hand for a couple hours and then all I was feeling was pain for a while. Everything healed alright in the end and I was good. Like he said follow the instructions and test a few times before you go hands on.
Good thing you healed up, ear damage is no fun.
Any damage isnt really but ear damage can be a menace for a while
As a "retired" long time club DJ: hear loss and ear drum rupture isn't as much fun as you might think...
@@Seelenschmiede Huh, guess I should cross that off my bucket list?
@@Seelenschmiede It was awful, felt like one of those war movies after the shell hits next to the protagonist.
at 5:20, you be heavily injured or dead, you maybe don't see the damage on the surface but internally you be pretty mess up...
He said you might not be dead
It might not be a bad idea to create a deliberate weak point in the cannon, so you have a reproducible failure pathway. Maybe a shallow cut 1/4" wide by 0.05" deep at the front of the large chamber. Make sure the cut profile is rounded to prevent very low failure pressures due to the creation of stress risers in the plastic. A round file might be a good tool.
When I was a kid my friends dad, who is a mechanical engineer, built us one that we used to set off with hair spray. He used pressure rated pipe and PVC primer and cement and designed it to be fired from about 10 feet away on a stand using long cables with the grill igniter. He also designed it so that if it failed, the end cap would blow off rather than the entire thing exploding. I don’t know how he did it but that’s what he said, and I trust him given the impressive projects he did as an engineer
you could probably friction fit the cap on snugly enough that it is 99.9% less likely to let go than a potato or whatever, using tape or putty or something similarly gap-filling. Look at ... uh, water distillers you can buy online, they're very leaky for the metal (copper) ones, you're supposed to either use PTFE (teflon) tape or "wheat paste" to fill the gaps in the connectors, and that has to both withstand moderate pressure *and* fairly extreme heat (steam under pressure is quite hot)
I UNDERSTAND THAT THERE ARE A LOT OF COMMENTS HERE, BUT PLEASE READ IT !
I also try to create interesting content (experiments). Will you write your opinion? dg
You just need to make sure the threads on the end cap will shear off well before the pressure gets to dangerous levels.
Impressive.
My dad would build ours out of sced 80. We would use hairspray, amd a grill igniter as well. Only we shot them off our shoulders. Obviously looking back it wasn't the safest thing but not the most dangerous either. Never had one blow up luckily
When I was a young teenager I wanted to make a potato gun but my parents said no and didn't let me get the materials I needed. Fast forward some time I found some old PVC that had been sitting out in the sun for a couple of years and built a potato gun out of that instead and kept it hidden from my parents. It worked fine for a while but on the last shot it exploded in my hands and even 15 years later I can still hear the ringing in my ears from it.
Ik heb 2 aardappelkanonnen, en er is er één nog maar een paar keer ontploft! Veilig zat!😌
@@superkip5920 net 'n paar keer...
@@Sundownnnn lol
Waarom praten we ineens Nederlands?
@@BigBodyBiggolo omdat Nederlands de beste taal ter wereld is!😀
4:39
This, IMO, is a great demonstration why mindlessly reinforcing everything might not be the gteatest idea. Sometimes engineers design stuff to have a specific weak points, so in case an item in question fails, it does so in a comtrolled, safer manner. Not exactly the same thing as I tried to describe, but look for example at a rupture valve
Holy crap, that pressure... I bet, that could cause not only lacerations, but also ruptured eardrums
Brooo the shotgun revolver thing at the end is awesome
My brother works for consumer testing laboratories (UL) and he says everything usually has to test 2 to 3 times over its rated limit. Swing set loads, pipe psi, shoe wear, you name it.
2.5 to 10 times for fluid conveyance. In some rare instances it is only 1.5 but that's usually for very large diameter or ultra high pressure products. 4 times is the norm.
Hey ask him about water valves. What is their safety rating
@@thomasbarlow4223 "They are tested to 125 psi and have to remain operational and to 500 psi and must not burst or leak but don't have to work after." -My brother
PVC pressure pipe is generally designed to withstand 3.2x the rated pressure in short term rupture tests. Check out ASTM D2241 or AWWA C900.
@@fordmanfinis tell him I said thanks. I am building something and want make sure its safe. 5000psi operation pressure surely must withstand 10k psi but I couldn't see much more than double safety margin. But hey I've been wrong before....
The way he looked at the camera is like: "I'd preferably die" 5:48
In a hydrostatic test the liquid does not get compressed,but the hose,the vessel in test etc. all store energy in tension .
That is why you still get an energetic release when failure occurs
I use mines with propane that I actually pump under pressure inside the combustion chamber XD. I add some fiberglass wrap around and everything is fine. And it acts as a protection again shrapnel if it breaks. You actually have to design a "weak part" in the cannon in a way that if it breaks, the weakest part of it will break first and explode in a non-dangerous direction (for example, the junction with the barrel will pop and the chamber is still intact, so you don't lose your fingers). Usually, when I'm having a failure, it's just the cannon that goes away towards the front like a dart.
Oh, and don't let your PVC under UV exposure. UV makes PVC really brittle.
Word of advice for next time; you can use argon while it’s on its side. Pressurized gas that’s not liquid can lay sideways and still dispense. Welders do it all the time (I have personally as well). So you could have set the tank next to you behind your barrier for more safety + ease of reading gauges. Great video!
I would also suggest a thicker plate of cardboard for protection. Like, at least two layers :D
Plus it won't fall over sideways and hit you in the head while you're hiding behind it...
@@TheWinjin That was sheet metal
@@recksnfx611 I guess you're right, it just looked like a piece of dark wood to me, but probably it's a rusty sheet. I think it would've been better with legs :D
highly recommend making the bottom part the weakspot.
its way safer having it just blow out the bottom instead of acting like a frag grenade
Exactly this - fail safe should be the design goal.
who cares about safety?
@@squidwardo7074 Is that you, Cyrus?
czcams.com/video/47Yxa9IeJEc/video.html
How about making the combustion chamber out of metal tubing where welding and fasteners are used instead of glue?
@@iceho6460 that sir is a pipe bomb
Me and my best friend in HS made a couple of these back in 01-02. We took them to the local football field during summer break and would sit in either of the end zones and fire potatoes at each other like we were enemy mortar squads. We used hairspray, and eventually swapped to butane because over time whatever additives where in the hairspray would stick to the side of the chamber, would stay lit and we didn't want to melt the sides.
It hurts like hell as well.
But then again I was using o² acetylene torch for fuel and was shooting potato half a mile
Wrap the chicken wire LOOSELY a few times around. That way, it will contain the fragments by bending and absorbing their energy. A solid, tight wrap only increases the stiffness, therefore raising the pressure rating - and also the damage it does when it ruptures at those higher pressures it can now whithstand.
I UNDERSTAND THAT THERE ARE A LOT OF COMMENTS HERE, BUT PLEASE READ IT !
I also try to create interesting content (experiments). Will you write your opinion? dg
I prefer using Kevlar condoms and duct tape. You’ll never have to worry about it blowing a load right next to your face .😂
Finally! The other day I was thinking about your channel, I was worried if you had abandoned it. Don't leave us too long. I miss your scientific experiments
I thought the same thing and you must have also done a prayer sesh the same time I did cuz we brought him back
@@corncobjohnsonreal LMFAO like praying is gonna make him upload a new video
How come religious folk lack common sense
@@Heroo01 I FELT THE VIBES
@@Heroo01 that's so rude, I'm making a joke and you're flexing your nonreligiousness like it makes you superior. Which is funny because it's really you that lacks common sense. AND I'm not actually religious I'm doing a bit. You really thought "prayer sesh" and praying backyard scientist back was sincere! Do you realize how absurd that is, and that you took it so serious that you felt like you had to insult religious people for it! It's so funny how oblivious you were, I think, I've been drinking bleach and that messes my judgment so maybe I'm the dummy and people take the youtube comments section seriously these days, which would be a good thing, let's clean this cesspool 🌻🌻♥️😊😊😊😊😊
If one day Backyard Scientist stops uploading, I don't think it'll be because he abandoned it
I made one a few years ago. Just used compressed air at 40psi. shot a plum, it was the closest fit down the barrel, over 150m.
3:38 When the pressure at the cylinder is 200 it will not be 200 at the pvc pipe under the dynamic conditions of your experiment . The gas is travelling along a very small bore long tube . You have to increase pressure VERY slowly for reading to have any meaning.
This man gets it. For the electric crowd, the PVC pipe is like a capacitor being filled through a resistor from a voltage source - we would have to calculate the air mass (charge) that had already flowed into or is currently flowing into it to infer the pressure.
I have personally been present in a room when a pvc potato Cannon exploded. My brother had made one using compressed air for the Oklahoma D-Day paintball game and we were testing it a bit. Then he thought it would be funny to put a piece of paper in it and launch it at my other brother's butt in the kitchen without him knowing.
So Brother A pressurizes the potato Cannon, keeps it REALLY low pressure so he doesn't risk hurting Brother B, (like 15-20psi tops) and goes to shoulder it. While lifting it up, his shoulder bumped the valve and dumped a little more pressure into it. I saw it happen, I reached up and shut off the valve and tried to stop Brother A before he fired, but he didn't hear me in time, he opened the barrel's valve and the rapid expansion of air made the whole barrel go kablooey. Shrapnel went everywhere, put a hole through a cabinet, took a small chunk out of the countertop, and one piece went clean through an entire roll of paper towels, out the other side and still managed to stick into the plaster wall behind it. It was crazy.
By SOME miracle, no one got hurt or injured except Brother A who had a medium sized cut on his hand that had opened the firing valve, but nothing that needed stitches, and some ringing ears.
I still remember it all like it was in slow motion. Have never forgotten it. And it's why my kids will not be left home alone unattended for extended periods of time when they're in their teens 😂
This is why I always stayed clear of compressed air cannons. While it seemed you could control the pressure more than using ignitable fuels, it just added another chance for something going wrong to me. I stuck to hairspray, and not clogging the barrel.
Glad you enjoyed the quad cannon! It was ridiculously fun to make (even more so to test it), and I truly appreciate the mention. I'll tell ya, though, your MGL style launcher looks absolutely amazing. I need one in my life like now. Can't wait to see the full video!
That was a badass creation man 😎
It's mgs for metal gear solid
We always used a clean out for the rear as a fail safe the cap is the only failure we’ve ever experienced and we always treated the area behind it as a back blast area
You should probably wear a mask when blasting fiberglass like that. It's not as bad as asbestos, but it still isn't great for your lungs, and this is almost certainly blasts a punch of small fibers all into the air. It's at least not really a carcinogen (that we can tell) but it is still pretty irriating and can cause some asthma/bronchitis like symptoms
When I was in high school my Physics teacher was telling us that when he was in college they had a potato cannon that they would demonstrate for kids are science outreach. One year, their professor decided that "hey shooting flame propelled potatoes at groups of small children is probably a bad idea." And challenged them to come up with a different idea. So some of his buddies had the idea to use liquid nitrogen as a propellant. They would put some liquid nitrogen in a water bottle, drop it down the barrel as a propelling charge with a potato, and let the bottle explode. They, of course, had to test this where there were no people, which is how they were almost arrested for shooting potato canons out on the residence quad green at 3 am.
Done this with dry ice, tons of fun! Until one doesn't go off...
I agree with Adam, the scariest explosive is the one that doesn't actually explode XD
*after a few drinks and some engineering.
@@Lizlodude A BB gun will take care of the ones that don't go off. ;)
@@8180634 better be a fricken pellet gun and not something you'd give a 10 year old
@@TheHippyProductions when they are almost ready to pop, it doesn't take much to finish the job.
"lock a kid in a room with a potato cannon and a live hand grenade"
Wise words to live by
imagine a soldier launching unpinned grenades from a potato canon.
the grenade would strike open as it leaves the barrel.
hahahahha
No pressure problem if you use threaded end pieces.
I built plenty of these and have had issues but solved them with a safety link. a Furco or rubber coupling in the center of the chamber 1-inch gap and abs glue under the hose clamp area. fail-safe plus a little expansion or give
Seem like you really like that bomb suit. Maybe you can make one and then try and see how effective it is for a future episode?
Glad to know I'm safe. The canon I built uses 4" pressure rated PVC and a bicycle valve to inflate up to 90PSI held back by a large ball valve. Turn it quick for maximum range. I think the hairspray or other explosive powered ones are more dangerous due to the higher (and uncontrollable) pressures possible.
yes the shockwave pressure spike can be far higher than the expected average gas pressure. Plus shock loading of a material has completely different effects than static loading.
@@avroarchitect1793 haven’t people found out the perfect dimensions for the pressure wave to hit the projectile or something?
@@fungdark8270 that isn't the issue, its the spike of pressure at the wave colliding with the wall of the tube. And if the spike is too high... well we've seen the results.
7:23
also another safety tip on the cement part. before adding primer or the cement, take some hefty grit sandpaper and rough up the pvc where you are gonna cement it, not too much scoring but just add some texture so the cement and primer really has something good to hang on to.
We made a potato cannon years ago out of ABS (all black stuff) and used a large gauge pipe to brace the combustion chamber. Basically cut the pipe in half lengthwise and put it around the original pipe, and then tightened it on there with a pair of large hose clamps. That was back in 1999-2000 and 23 years later it's still holding together.
0:23 I love that they used the minecraft tnt sound effect
0:30 I was so confused when I heard my local new’s jingle! I thought they interrupted CZcams for a weather alert haha
I remember building one when I was 9 but never tested it because of noise concerns. Kinda glad I didn’t and later went with lower pressure smaller air cannon manually pumped.
I love that ending!
Super excited for the next video. In high school, I envisioned a pump-action, cylinder-fed semi-automatic potato cannon. I went so far as to draw up plans and purchased valves and PVC, but never got around to building the thing. Mine was designed around the action also pumping a specific amount of propane and air into the chamber, and in hindsight I seriously doubt it would have worked at all.
It may work
0:15 geez, who would have though that DIY things used masses cause more injuries than things not used by masses :)
The 230 psi is the WORKING pressure, that it can handle all day everyday. You generally have several magnitudes of safety factor between those.
Most use pvc that isn't exactly pressure rated, that or they don't replace the parts that deteriorate with the heat from them being used with high temperature reactions, that or they use something that works as a solvent to slowly deteriorate the structural integrity of the pvc over time.
If you ever end up doing fictional content, would LOVE you in a series about a bare budget super villain trying to work your way up... cause your non-fiction content fits that motif perfectly
Might have to give them names like "Potato Launch-inator" 😁
Oh no, Potatoelaunchinator has striken again with his Potatoelauncher 3.000!"
When pressure testing with water you have to make absolutely sure there is no air anywhere in the part or that will be the result, I worked at a water treatment equipment manufacturer for 22 years and we pressure tested tanks about every day and when done properly it makes a loud bang but doesn't send shrapnel flying
Was involved in many pressure tests in construction. Doesn't take much to have a failure. Also have hit a few pieces of PVC pipe when excavating. That stuff grenades uncontrollably. Always cut it with a saw instead of the excavator. I enjoyed others and their potato guns, from a distance that is. I don't trust any explosives 100 percent. Seen the unexpected even in the Army, in a controlled safe environment. Energy/explosives is something to be wary of.
I remounted a 10 foot long compressed air cannon (made from 6 inch PVC ) on a trolley for mobility but didn't like that even at the relatively low pressure of 120 psi there was no way to contain fragments if the 10+ year old cannon ruptured. I took hardware cloth with 1/4" mesh and triple wrapped the air tank area so that if a crack or break happened all pressure would pass through but would contain shrapnel.
Excellent work. I really appreciate the data.
"I want to test when they explode" - *puts himself into an even more dangerous situation by almost dropping a gas bottle*
Seriously though, pressurized gas bottles must ALWAYS stored such that they can not tip to the side, either by securing them with a chain or belt (as shown a few seconds later) or by simply laying them flat on the ground. If they tip and the valve gets sheared off, you've got yourself a missile that will easily make its way through a cinderblock wall.
I saw that happen on a Skyscraper Roof, with a bottle of HVAC Refrigerant. The boys were laying it down on its side when one slipped. The bottle spun in circles for a bit, getting faster and faster, and then launched itself off the roof. And rocketed like the missile it was between Skyscrapers down a Major Municipality's Street. And then went kerplunk in the Bay, about a half-mile away..
It was a good day to burn off some excess luck.
"A cinder block wall"????
More like a dozen cinder block walls.
@@TimeSurfer206 One of my teachers always told us the story of how he sat in his garden when suddenly a gas bottle impacted a few meters next to him. Turns out it was from a gas station 2 km away. Tipped on its side and flew off.
Edit: Typos
@@whynotjustmyusername I am not at all surprised or skeptical. I grew up IN a Welding Shop: My Grandpa's.
the cap was on
Hydrotesting or otherwise testing it is of limited value if you don't know what the peak combustion pressure is. I'd love to see someone do a series of tests with combustion of different fuels and fuel air ratios, potato types and weights, and other factors - with a pressure transducer hooked up to an oscilloscope or other fast measurement device
By the first law of thermodynamics, the pressure within a fixed-size container is proportional to number of particles (molecules of gas) times absolute temperature, so the combustion has to either produce lots of gaseous molecules, or heat the gases by a lot to increase pressure. Like to increase pressure by 10 times (say, from 1 atm. to 10 atm.), the number of co2 and h2o molecules produced by the combustion has to be 5x greater than the number of molecules consumed by the combustion and the whole thing has to heat to 2x the room temperature (~590 kelvin or ~600 °F). Solid explosives do both of those, therefore you get a detonation and a fast-moving pressure wave, but hey, if you put that in your potato canon, you already know what to expect. For anything more conventional we can assume your fuel and oxidiser are both gaseous and at normal pressure of 1 atm. (fuels such as gasoline or methanol are still gaseous, because only the vapours actually burn). With conventional fuels you can't really get a detonation unless you use high compression like inside an engine, so the pressure across your entire container will be more or less uniform, no need to worry about peaks and how to measure them. Also with conventional fuels the number of particles produced by the combustion is pretty close to the number of particles consumed for the combustion, so the only factor that actually increases the pressure is the heat.
Now to answer your question: as long as you use gaseous fuel and oxidiser and don't pressurise them, the only way the pressure inside a potato canon could ever reach 10 atm. would be if your combustion heated the whole thing to 2950 kelvin (4850°F), and 10 atm. is still way below anything shown in this video. Just don't put explosives or pressurised fuel inside and you're good.
@@hitnovak i like your funny words magic man
@@hitnovakmakes sense to me. Maybe just don’t use Oxy Acetylene as your gas.
@@Binford2500 Yeah, pretty much the take-away here. Hopefully people with access to acetylene already know that.
So you mean.... bomb making instructions on youtube?
Hahaha the way you lead into your ad was perfect.. come on honey daddy needs a new bomb suit!
Cover in flex seal or wrap in some duct tape etc
When it blows your good to go.
I know i caught this video kinda late but what nobody mentions somehow
is that pvc shrapnel is very dangerous for one particular reason
if it happens to become embedded in a person its a real pain to remove all of it
since it has a similar density as human tissue and does not show up on xrays
how small of a shard does it have to be to not show up on an x-ray or does it just not show up at all?
@@acewmd. As far as I know, it is really hard to see, no matter the size.
@@joetuktyyuktuk8635 oh, well thanks.
Good knowledge..
True, it is much harder. But the army has come up with some pretty amazing methods for detecting non-metallic shrapnel in the last decade and they are making it to the general public
Just started watching the video but already I want to clarify that the failure PSI rating for PVC varies WILDLY by ambient temp. At colder temps it becomes quite brittle. This is also true for CPVC (the more yellow variant used for drinkable water supply lines), but less so.
still have my rifled pvc barrel i ordered online in like 2001, the first thing i ever bought online
That first build guide I ever used (early 90s) said to use ABS on it, and not PVC. It's cheaper the other way but, also not safe. I never had issues with mine ever going boom.
Learn from the pyros.
There is a reason regular pvc isnt used for mortor tubes.
Great video! People often ask us if they should build water rockets from PVC, and we always recommend against it for the reasons you show here. I'll be able to point them to this video from now on.
Every year my family gets together for a family reunion on Memorial Day. The favorite tradition on that day is to load up a potato gun with candy like tootsie rolls and bubblegum and then launch it at high speeds to all the kids waiting in a large field. We used to do suckers, but we had to stop after one shot through a car window leaving a rather nice hole.
If you have the time, try HDPE instead of PVC. When it fails, it splits the side instead of shattering into shrapnel.
More difficult question - does PVC fatigue and get weaker with use? Assume it is painted to protect from UV damage.
Thanks for putting some numbers on this! I never thought of using hardware cloth to reinforce fiberglass - very clever whoever thought of it.
5:54, amongus
Lol how did you see that
@@Robododobobo i dont know💀
!
A few years ago, I saw a video of a French youtuber who built a potato canon out of steel that used oxygen and acetylene and with a barrel which had the exact diameter for golf balls. Let's just say it was pretty powerful.
Kevin: So today we made pipebombs
7:45 made me laugh maybe the hardest I have this year. Dude that was well done.
7:45 You still had a lot of air in it.
For those who are unfamiliar with hydrostatic tests: The cannon exploded because it was still pressurized with a compressible gas. To ensure a safe hydrostatic test the system needs to be pressurized using a water pump. The presence of gas anywhere in the pressurized system can cause a failure to become explosive.
I UNDERSTAND THAT THERE ARE A LOT OF COMMENTS HERE, BUT PLEASE READ IT !
I also try to create interesting content (experiments). Will you write your opinion? dg
He tried that in the video
@@supremesloth105 He filled the cannon with water, but you can see he is using the same air line used in every other test to pressurize the cannon. The compressed gas in the line (and in the off-camera tank) is what caused the explosion.
@@nathank7989 ahh, yea that is interesting
That picture looked like a young earth creationist, and that makes it better.
You could use galvanized piping steel instead of PVC, it would be much heavier... but you have the spiritual equivalent of a naval cannon.
Dude- I've seen countless honey ads, but when I saw you could save $1000 on something as obscure as a bomb disposal suit, I finally joined and with your discount.
7:23 I like your definition of "safe"
"Glue everything together properly so that the canon rips itself apart and disintegrates into 1000 pieces rather than blowing off the bottom"
you're never going to get 1000 psi out of any kind of potato cannon when its not blocked
I used ABS and I didnt glue it together. Its just a really tight fit but if it over pressurizes by using the wrong fluid or if the potato gets stuck then in theory it should just fly apart .
Dude I'll give you a like for that perfect honey promo after seeing the price of the bomb suit and that glance, holy smoke that was hilarious.
I used to sell plastic piping systems. I had a customer (a municipality) have a 16” sch 80 PVC manifold explode with only a 60PSI “bubble” caused by a failed air release valve. While the system was being filled with water after a backwash cycle, the air release valve failed and all the air in the system had nowhere to go. The explosion was heard a mile away and sent shrapnel up to 300 yards away including multiple 100+ lb chunks. One of them totaled a car that it hit. The operator was protected by a concrete wall. But he’s now deaf. There are compressed air plastic piping systems that are specifically designed for that. Either ABS, or polypropylene. Those materials are far more ductile and tear when they fail. PVC fractures because it’s brittle. PVC SHOULD NEVER BE USED FOR COMPRESSED AIR. OR COMPRESSED GAS OF ANY KIND. I DON’T CARE IF ITS “DONE RIGHT” OR NOT. DON’T DO IT!
Are you family of Juan ?
Now I want to make something that can be heard a mile away too!
The 60 psi in a 16" pipe makes me wonder if it was something like that torque vs. horsepower thing in engines. 16" of air would exert more force than 3". So less psi may be needed to burst
I am wondering if this might draw a "Destructive Device" visit from the BATFE... wouldn't be the first time youtubers have been visited.
I'd want to see a link to the news story on this before I believe it. Schedule 80 failing at just 60 psi?
When it comes to hydrostatic testing, the goal generally isnt to pressurize untill means of failure. To add on to this, you used a pnumatic over hydrolic test which at high pressures (above 135 psig) can quickly become unstable due to a large void forming on the top of the tank.
I test hazmat and high pressure tanks as my career, seeing a quick or semi false statement as to say "it diddnt make a difference" just urks me. Even though you would use a hydrostatic pump to correctly test your rig, we use posthole hydrostatic pumps to test NH3 and LPG tanks, it DOES reduce the explosive potential, but its still 400+ psig.
Never do this unless you are a trained professional and always wear your PPE Florida man! Haha!
Edit: this is just for the grammar nazi. Im not checking my spelling for you 🤙
Yeah... can that happen to my 3000psi and 4500 psi carbon fiber and aluminum tanks for my rifle?
@@EC-dz4bq if you over pressure them then there is always a possibility. Always keep within the maximum allowable working pressure. There are also factors like material fatigue and tempurature cycling. Look up the data sheet on your tanks and see what or if there is a expiry for wear. If its say 10 years of use then ditch it then and get a new one, but composites are much different than stainless, mild steel and aluminum.
@@shout_2000 I assume the burst disks would prevent that (for the most part?) My pump I use pump it up, also has burst disks. (Mine is not homemade.)
Also, all my tanks are made by the rifle manufacturer. They claim to have a lifetime warranty(rifle + tanks), with proper care. So I assume I don't need to change them out?
Edit: Not a sponsor, but if the tanks/rifles themselves may help answer. They are Airforce Texans, and Texan SS. Also, I have larger recharging tanks...would those be different?
@@EC-dz4bq not an expert, but I would assume that the lifetime warranty would be trustworthy, as long as you don’t do things like subject the tank(s) to over-pressure, high temperatures, long exposure to sunlight, etc.
@@gruntopolouski5919 Thank you
My potato cannon, which was made around 1995, has a pressure release system. Basically, instead of blowing up the back blows off. It can then be easily reinstalled. I do agree that it is still on the dangerous side. Someone I knew made a potato cannon that he over filled with propellant and did not listen to me about putting in some sort of pressure regulator. It blew up and he ended up in the ER.
I love that cut to ad
You said to glue on the end caps well for safety, but if you expect them to potentially fail it seems like the best place for the cannon to explode.
My dad and I made a pneumatic tennis ball “cannon” out of schedule 40 PVC when I was a kid. He based it on a design he’d come across while researching where the tank sat under the barrel to shorten the overall length, so it needed two 90° pieces to connect the tank and barrel. One time I thought it would be cool to fill the barrel with water and dump about 100psi. The weight of the water was too much and instead of blowing the water out in a spectacular mist like I’d imagined, it instead just blew the piece between the 90° fittings and the water just drain out the back. The piece that blew out was just inches from my feet and somehow I didn’t get so much as a scratch… afterwards, he tweaked the design by adding two T pieces to increase the area and it still works today, 20 years later
I made the ultimate potato gun. I started with a Gaither Bead Bazooka, an air-powered tool for tire shops to help seat difficult tire beads. It just uses compressed shop air. I unscrewed the diffusing tip and replaced it with a male-threaded copper connector that replaced the diffuser, sweat-soldered to a 14 inch length of 1-1/2 or 2 inch copper pipe. You simply press the open end of the copper pipe into a potato, getting a perfectly-fitting projectile. Charge the Bead Bazooka with compressed air, aim and fire. I get powerful and fairly accurate shots at about a hundred yards.
If you want less distance / power, use less air pressure.
I have made many potato canons in my youth. I always used the pressure rated pipes. I always duct taped mine for looks, not because I thought it was safer. I always used the cheap, old school hairspray. Always sprayed the minimum, always got a good pop, plenty of power and more than enough thump from the end result. Never had a problem. Problem is the types of fuel a lot of idiots think is a great idea to use as an accelerant. Over complicate it, then yes, prepare for potential consequences of an extremely overpowered, over pressured potato canon. Use a practical fuel, properly glue together, use proper pressure rated pipes and you’ll likely never have an issue. It absolutely comes down to the person constructing it properly
When you're relying on atmosphere for your oxygen supply, less is more when it comes to propellant.
Ditto. I tried other things here and there, but determined that hairspray was perfect. I also learned quick not to load more than one projectile...
I had a potato cannon when I was like eight, and I was showing it to my friends when they were over for a play date. My mom called us up from the treehouse because we had to go, so I want to relieve the pressure in the chamber so I just pulled the valve. Somehow, someway, the CO2 cartridge that was loaded at the time angled itself perfectly and hit my mom square in the forehead.
Was your mom ok?
@@infinitespiral4151 She died
@@sawyerh6838 you could've worded that better 💀
@@Mr.Shogun true, it made for a poor epitaph
@@sawyerh6838 how do you know?
we used hair spray at the end and screwed the end back on. We installed a lantern igniter so when you turned it, boom.. we never had issues with it. It would shoot them pretty far!
Have you ever installed a gauge to show what maximum pressure when you're shooting is? I'd like to see that. Easy to do with it diesel compression gauge that will remain at whatever it's highest pressure was.
15 years ago my brother and I had a cannon building contest. He built PVC with a grill igniter and some hairspray. I built mine with 1/8th inch thick, 2 inch diameter steel tube, 1\4 in steel wrapped lower for chamber, that runs on Oxygen and acetylene from my cutting torch. It sounds like a tank cannon, turns potatoes to a fine mist, and puts tennis balls thru 1\2 in plywood. I won......