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I'm still alive btw.
I've been living in fear of my ghetto 9p tubeless inflator exploding ever since I made it. There's a lot of stored energy and I always wondered what would happen if it went boom. But it's seated numerous tyres over the last decade, so it's had a good life. Anyway, today it started slowly leaking air due to a tiny crack in the cap, so I couldn't get it above 100psi. I was grateful it hadn't exploded so I popped to the shop to get a new bottle (for the record, a Co-op sparkling mineral water bottle for 49p).
Got it home, drilled some holes, pumped it up. On the first attempt, the tyre didn't seat. Damn. More pressure needed. I was aiming for 120 psi but at 110psi... BANG! It made me jump but it didn't kill me or anything. I don't think there's even any mild tinnitus. Something whipped up and caught me on the hand though, which is kinda sore.
What I think is kinda interesting is the way the thing broke. I don't know where the initial rupture was, but the top cap split, the top part of the bottle sheared off, the main body of the bottle split in many directions, and there's a separate (not connected) hole in the bottom of the bottle.
So, at least I didn't die, but I think I may have been a bit lucky. It wasn't as loud as it could have been, but something hurt my hand and I suspect if I'd been in a different place I could have been hurt. On balance I'm more scared of the same thing happening again so I might invest in an airshot type thing.
Sidenote: In retrospect, my 2021 bottle was a lot thinner than the one I bought a few years ago. I supposed we should be grateful that less non-reusable plastic is used in today's bottles but my experience today suggests it's not as good for ghetto tubeless.
Just need a few wraps of tape.
Interesting, I thought about trying something like this but just bought a pump instead. I wonder which drinks cos use the best bottles.
Are there other safer vessels you could use? Aluminium water bottle or similar?
I use a Robinsons bottle. Nice and thick - works like a dream!
slightly more than 9p but still less than a quid
When I did one, I wrapped it in Gorilla Tape.
I did this to strengthen it, but also with the thought that if it failed the parts might hold together, rather than be thrown all over the place.
Might be worth doing if you build a new one.
If not, I can recommend the Lifeline tubeless pump/inflator.
Slightly gone up from the £50 when I bought it though.
Just need a few wraps of tape.
Yeah, I did that on my old one. I couldn't find my duct tape so I didn't bother this time round 😐
However, I'm not sure that the tape would actually prevent the plastic from stretching. Duct tape can be stretched a bit - I'd have thought the plastic might split before that amount of stretch.
Are there other safer vessels you could use? Aluminium water bottle or similar?
You want total volume of air so I think those alu water bottles are mostly too small. I like the fire extinguisher idea someone did. Or an oxygen cylinder or the like.
I made one from an old ballon helium tank left over from my daughters birthday party.
My ghetto inflator is 9yrs old. I keep it inside the leg from an old pair of jeans and wear safety specs.
Every time I use it I expect it to be the last but it keeps on going (2L coke bottle)
Best 9p I’ve ever spent on bike kit!
I once when using a track pump had the misfortune to have a road bike tube explode at around 130psi it was quite the bang.
Enclosed garage as well, it was like a shotgun
Brown trousers..
I blouse out at 100 now.😅
I grab my safety glasses even when using my official Airshot!
You need to use a fizzy pop bottle as they are designed to take pressure, wrap in tape and you are off
The random joys of whisky cloud generation has the same perils.
Mine is an old expired fire extinguisher that I got for free. It's too big really, but on the other hand I asked the fire extinguisher tester dude what pressure it was good for and he said something like 3600psi.
If it does explode it'll probably kill teh whole street though. And there's the whole "what if there's a fire and someone tries to put it out with compressed air" issue.
There is some great materials science in the double blown pop bottle. I think the new bottle was lower technology
Works for birthday cakes...
Something whipped up and caught me on the hand though, which is kinda sore.
Just superficial injuries then.
IGMC
Mine was a 50p garden sprayer from a jumble sale. Could never get away from the thought that if it went they’d be picking bits of me and the yellow plastic out of the garage ceiling for days.
Since replaced with a compressor which is ace.
You pumped a PE bottle to 110psi and you're surprised it failed?
You want total volume of air so I think those alu water bottles are mostly too small. I like the fire extinguisher idea someone did. Or an oxygen cylinder or the like.
I made my inflator using a cheap old 500ml Aluminium bottle, it works an absolute treat.
It's not so much that you need massive volume as much as it is flow rate really. a rapid blast from a 1/2L at say 60psi might well be enough to just about seat some tyre/rim combos so long as it dumps the volume through the valve fast, you can add more pressure with a track pump once it's seated.
I did have a proper compressor with a 5L tank that would go to 10 bar (IIRC) but it didn't actually deliver as good a flow rate, plus it was getting on and would eventually fail far more catastrophically that your lemonade bottle contraptions, so I chopped off the hose (useful) and binned the rest...
My little Sigg type bottle will certainly go much higher but TBH I wince at around 100psi, I'm not trying to seat fat tyres, but if that won't seat a 2.5x29" tyre, nothing will.
I once when using a track pump had the misfortune to have a road bike tube explode at around 130psi it was quite the bang.
Enclosed garage as well, it was like a shotgun
Brown trousers..
I was once in a bike shop when this happened. There was a dog in the shop. There was actual poo on the floor afterwards.
Human or canine poo?
If you think that gives you a fright try tipping and 1100 bin into the back of a dustcart only to discover someone has dumped a full and charged CO2 fire extinguisher in there. That makes quite a bang and a very big cloud of CO2 and a big cloud of debris flying out of the back of the truck.
I've never needed to put more than 60psi in mine for all sorts of tyres and rims up to 29x2.5 so I'm surprised people use double that! Mine has served me well for years, definitely my favourite homemade bodge.
A few years ago I test fired an empty wet chem fire system on a fryer, in a food factory. This was a very expensive custom engineered system from somewhere in Europe.
Turned out the regulator was made of plastic rather than brass and expired in an exciting manner, with me standing next to it. It was quite loud with 80bar of nitrogen and left a couple of bruises.
Any excuse to post The Frankenflator.
That must have been a bit scary, glad you are mainly OK @Super. 100 psi is risky, I saw a video on Youtube where a new one exploded at 120psi, so I don't go above 60. I tape the bottle up to prevent shards as well (given the stiffness of the HDPE or whatever it is they are made of, no tape is going to make them stronger). And I wear safety glasses.
I always use a Coke bottle (I read somewhere that they are rated to 10bar) and wrap it in duct tape.
I’m also careful that it doesn’t get scratched or dented and I replace it maybe once a year. I never pump it up to above 4 bar anyway.
My first one I tested by filling it with water then adding air (less stored energy since water is incompressible). I tested it up to 150psi so felt justified in using up to 120psi.
60psi in a 2l bottle is definitely not enough for me to seat difficult tyres. I use a compressor most times so only use the bottle for difficult tyres. I might try a 3l coke bottle if they still exist.
I once when using a track pump had the misfortune to have a road bike tube explode at around 130psi it was quite the bang.
Ha! On a club ride to Windsor, to the Cinnamon cafe a well known cyclists haunt (pre-Covid, obvs) one of the group got a slow puncture on the outskirts. So we topped up and rode on knowing that Nick the owner has a toolkit to lend out, and we could fix and pump using a track pump while waiting for the coffee.
It wasn't me but in hindsight the puncture guy did say that he thought he was putting a lot in, but when the tyre popped off and the tube at by now about 300psi went bang in the confines of the old station concourse (if you know Windsor you know where I mean) it was more than him that shit himself. I swear several hundred tourists hit the deck fearing a terrorist attack, we were under fear of a battalion of Coldstream guardsman deploying, not to say potentially some royal close protection people from the castle.
Then Nick saunters out, and casually mentions that he thinks the gauge is a bit faulty......
I used cheap 2l water bottles for my ghetto inflator with tape over them. Used to go to 100psi with that. I'm the end the creaking noises got to much and I bought a proper one (beto, only about £30 when I got it).
I might try a 3l coke bottle if they still exist.
I think you have to wait till next christmas
The thought of this happening and then sending plastic shrapnel across the room at light speed has terrified me for years. Even worse, the idea of the valve being fired like a piston out of the top and me having to explain to A&E why I have a presta valve embedded an inch into my abdomen.
I bought one of the specialised airshots. Frankly, it still scares me when I go above 120psi (which has been necessay, ****ing vittoria barzos).
I’m also careful that it doesn’t get scratched or dented
Keep it out of sunlight too.
Mine is an old expired fire extinguisher that I got for free. It’s too big really, but on the other hand I asked the fire extinguisher tester dude what pressure it was good for and he said something like 3600psi.
If it does explode it’ll probably kill teh whole street though. And there’s the whole “what if there’s a fire and someone tries to put it out with compressed air” issue.
Same thing here, got it from work when the fire safety inspector was around. He even tested it to 2500psi for me to make sure it was safe!
I've toyed with the idea of polishing it or covering it in stickers so that it doesn't look like a fire extinguisher though as I have the same worry as you!
I always used to cover my ghetto lemonade bottle with an old towel, as even with a few strips of duct tape for strengthening I was always wary of it exploding
Surely tape will just tear in any explosion?
The idea of wrapping it in towels or old clothing is much more likely too work. Think of it like the turbo/supercharger on race cars, they're wrapped in loose Kevlar blankets to hold all the bits when they blow up. It lets all the gas and explosion out so doesn't tear, but holds all the shrapnel.
This is why I converted a fire extinguisher like bigblackshed.
Plastic bottles are a terrible idea, but then so is paying £50 or whatever for a proper one.
Mine is made from an old Firetrace bottle. An extinguisher you might find in an agricultural machine or milling machine.
I used this one as it has a gauge and a flexible dip tube which can be re-used as the hose.
https://www.flickr.com/photos/153635742@N07/51031576378/in/dateposted-public/
Surprised at some of the high pressures being used. Never gone much further than 50psi for my tyres with my 2L bottle. Was well chuffed to 'upgrade' to a 3L bottle last year when I found one in the local corner shop....strange how youve more chance of finding a 3L a small shop than the big supermarkets, guess its a cash and carry thing
A 2 litre PET bottle should hold 120psi. The picture appears to show that the neck area has gone - faulty preform, I'd say. I'm more worried about the cap blowing off than the bottle exploding. Mine is about 5 years old and still going strong. 1.5L bottles are stronger, FWIW. They are often blown from the same weight preform as the 2L. However, you don't see many in the UK. As long as you use a bottle which contained a carbonated product you should be fine up to 100psi.
Really you want your tank to be capable of withstanding 1.5 times it's operating pressure.
100 plus psi.! 😮 I never have gone beyond 50.
Mmmm 3L bottle, local off license here I come.
Anyone else disappointed that this hasn't turned out to be the 2021 version of the infamous Badger thread?
I thought the advice was to wrap ghetto inflators in an old jeans leg or similar?
Mind you, I overinflated my daughter’s netball which let go some time later with an almighty bang, and blew out the side of her kitbag…
Little lockdown project. From this;
To this;
Total cost was £13 plus an old innertube and took about 30 mins.
The extinguisher is tested to about 370psi and pressurised with powder to around 270psi (if memory serves correctly). So tubeless at 180psi or below shouldn't be a problem IMO.
Extinguisher here;
https://www.screwfix.com/p/firechief-dry-powder-vehicle-fire-extinguisher-600g/91740?_requestid=726409
Works better than my tubeless pump to be honest. Mainly as it stores more air.
The extinguisher is tested to about 370psi and pressurised with powder to around 270psi (if memory serves correctly). So tubeless at 180psi or below shouldn’t be a problem IMO.
Except you've just drilled a randomly sized hole in a random place on the pressure vessel so those ratings now count for sod all. It's probably fine but I wouldn't rely on those figures for anything now.
I have a big (5l?) CO2 bottle, I used the test port to fit a schraeder valve for filling and converted the horn connection to accept a quick release schraeder head. No drilling required, just a lot of converter pieces!
Why drill it? Pull the handle or put a band around it and you can fill it via the outlet. Just needs a T and a isolate valve. But yes way better than a pop bottle.
No need to buy a new extinguisher. Plenty of used ones out there if you look around. There's always a big pile at the dump if you can sneak one out.
As well as the exploding fire extinguisher in the dustcart this has brought back memories of the compressed air launcher we had at the MOD. Basically a huge tank pressurised to some ridiculous level with a steel diaphragm with a small explosive charge in the middle of it. Blow that and the air launched what ever item we were testing down the test track at incredible speed. I hated being in the control room for that, I think everyone did. Watching all these dials and pipework while the whole thing charged up making horrible noises. Always felt like being in Das Boot, sinking to the bottom just waiting for imminent death! 😬
Not as pretty as @bigblackshed Frankenflater but does the job:
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