Sciencemadness Discussion Board

4th of July Safe noise makers

gonif86 - 12-3-2021 at 03:59

I am a mature responsible person looking for safe alternatives for July 4 noise.

Any suggestions using fuel air or chemical reactions.

I am long past the home made M80's of a misspent youth.

B(a)P - 12-3-2021 at 12:04

Didn't you just say in your last post that you had it sorted with your calcium carbide sound cannon?
Pyrobin is a good source of ideas for pyrotechnics.
What in particular is it that you found unsafe about your previously constructed M80s? What aspects are you trying to improve.
Obviously there is a massive range of reactions that result in a bang, but how you initiate them safely is the trick, assuming they are not likely to initiate themselves.
Are you happy with something that initiates with a fuse or are you wanting something else?

gonif86 - 13-3-2021 at 01:27

My gas cannon works great but I am looking for other ways.

I obviously need to give a lot more thought to what I want and do not want to create .

Pyrobin was a great suggestion thank you

Fantasma4500 - 26-6-2021 at 04:00

i personally use butane-oxygen at a ratio of 6.5 to 1, 6.5 being oxygen
just last night i set off 100L garbage bag in a big open field, it gave approx effect equal to 300g KClO4 flash or more. theres one drawback on this, it takes time to set up, it can be very dangerous to light and you cant do it if the temperature is lower than the boiling point of butane

the procedure is as following: clamp the end of a garbage bag with strips (i just use rolled up aluminium foil)
empty the bag for air
fill it up with oxygen, clamp the end tight and take approx measurements, math out the volume
for 100L bag you use 35g butane, easiest is to weigh it out, butane has around 0.6g/cm3 density.

you can also do this in smaller sizes but it gets more tricky with approximating the butane as when you pour it in you will lose some, best to shoot for negative oxygen balance, for a bonus of fireball too.

to ignite it, the best would be electronic but that just adds trouble, with a garbage bag you can go with just some shredded newspaper with hand sanitizer or similar fuel to boost the burn, but if you overdo it you get hurt.

i have used jugs in the past but you end up spending 3x as much oxygen as needed to fill it having to purge out the air already in there, or specifically the nitrogen in the air, i would drill holes through the sides and insert a small fuse which the flames on the outside of the jug could then catch and move into the jug easily and quickly.

you dont want the fuse to be too long because butane being quite heavy will sink lower so you want to be able to shake it gently and then have maybe 30 seconds worth of cardio. i highly recommend not using visco or similar fuse as they give off sparks, and youre dealing with a gas
with larger volumes you wanna bring some hot water to pour over the bag to get the butane to evaporate inside the bag faster

as for the butane itself, you wanna stuff it in the freezer so that it comes out liquid and not as a gas, for getting it out you can try taping a piece of metal with a small hole in it to a fork so you dont get to freeze your fingers, you also wanna wrap the butane bottle in something insulating so it stays cold, i personally just use lighter fluid.

just for a gauge of how hard this stuff goes i filled a 1.5L soda bottle with butane-oxygen and it had me deaf at around 10 metres distance, in urban setting

i would advice against using acetylene because the bottle is heavy, its expensive and very dangerous to handle, ive heard of accidents where the acetylene ignited in the plastic bag while being pumped in, acetylene is hyper-static sensitive

in my area i can swap a 5L oxygen bottle for 100 euro, thats 5L at 200 bar = 1000 liters
i have a little cute bottle at 2.5L 200 bar, and i had to pay around 65 euros for it, its handy however.


pros: heavy deep boom, cheap, available, non-illegal ingredients, no shrapnel, very easily scaled up
cons: must be careful, takes time to set up, cant have it in your pocket