from  work @ pawnshop i got 4 2lb cans of calcium carbide thats been sitting there for 4+ years. ( you get a rock of it wet it forms acetylene gas) been making my own carbide cannon aka noisemaker. too many homes around mine to make one to fire projectiles. but plans after finishing motohuffy, then my computer, is to find a used 12ga or 10ga shotgun barrel from either gunbroker or ebay around 25 or so drill a hole near end. and cap off the very end, drop 2 rocks in, a little water, cover hole and then light it. or 2 rocks ina  balloon THAT is slightly more dangerous, cause it has to get near a fire to detonate. mainly a fireball. not destructive. ( unless it hits me. ) anyhoo  dangerous or not, what do y'all do for amusement? sorry am bored off my mind atm. lol

ahhh that answers my other thread question... cool enough Yama .. but .. a shotty barrel? .. wouldn't be easier to just get 3 feet of 2" thickwall steel water pipe from a scrap dealer?... weld or threadcap the end? .. sure gun barrels are harder/better steel but it also is harder to work with .. 

Quote from: Janx101 on September 05, 2012, 07:13:55 PM
ahhh that answers my other thread question... cool enough Yama .. but .. a shotty barrel? .. wouldn't be easier to just get 3 feet of 2" thickwall steel water pipe from a scrap dealer?... weld or threadcap the end? .. sure gun barrels are harder/better steel but it also is harder to work with .. 

good points pipe is thick enough. will give that a go. i have plenty of pvc, but i blew a piece up today it rattled my nerves. and police werent amused over reports of explosion like sounds coming from the area. they could smell the acetylene at/near my home lol. so i was honest, told them i was buildinga carbide cannon. it self destructed. ( i did liek when i said, it took the rest of my carbide with it. still have almsot 4 cans left lol

PVC??!!!  ... err no.. nope .. uhuh ... baaaaaad...

well... for a orange gun with ether propellant pvc is ok... but acetylene is fair bit higher on the pressure scale i think?...

still... overall ... start with small 'loads' and approach higher amounts with caution... lots of caution .. i'm thinkin about shrapnel damage... it'd really ruin your day if a foreign object/metal shard was stickin outta your noggin! .... yeah one end of pipe is open .. but .. stress fractures/strains ... overpressure/overload blowbacks .. got any safety screen ala mythbusters style?

errr .. Yama ... #1 find an oildrum ... #2 use your supplies .. #3 get yourself a burning rag on a stick ... #4 be careful!!

http://youtu.be/EV95uJ0DiuY

Quote from: Janx101 on September 05, 2012, 09:29:04 PM
errr .. Yama ... #1 find an oildrum ... #2 use your supplies .. #3 get yourself a burning rag on a stick ... #4 be careful!!

http://youtu.be/EV95uJ0DiuY

found a double barrel shotty setup . but i wont win that. but i do need a piezo ignitor. anyone have one lying about. ive decided against pvc.  because id need some decent pressure to get a bang. i live surrounded by other homes. around mine. so projectiles other than wadding are a no no. just wanna make noise. steel pipe seems best idea ive got 2 pieces of lexan plastic each a half inch thick. so both together should help with shrapnel. or if i make a small barrel/short barre3l, can quadruple the lexan, for more protection. 

Ah, humble pvc. I think it was 1" pvc that nearly perfectly sleeves a C cell battery. Made a pneumatic 'potato' cannon like that. Only shot I ever found was 3/4 mile away from 10psi - but we usually pumped it up to 100. That thing had some kick to it too.

It made a real weird sound though... about what you'd expect a c-cell battery clattering along the imperfect walls of a plastic pipe at a few hundred mph to make.

Quote from: Badot on September 06, 2012, 09:04:33 PM
Ah, humble pvc. I think it was 1" pvc that nearly perfectly sleeves a C cell battery. Made a pneumatic 'potato' cannon like that. Only shot I ever found was 3/4 mile away from 10psi - but we usually pumped it up to 100. That thing had some kick to it too.

It made a real weird sound though... about what you'd expect a c-cell battery clattering along the imperfect walls of a plastic pipe at a few hundred mph to make.

kinda like "wapawapawapawapawapaffft" aka bouncing along and out of it. im bidding on a double barrel shotgun barrel on ebay. odds are ill get outbid, but if not, ill hav ehte perfect carbide cannon. for marbles etc.