SpudFiles

hi
i currently have a combustion cannon, the chamber is 4in x 15in, ~210 in^3, with interchangeable barrels. It has propane injection, chamber fan, and grill sparker ignition.

it works wonderfully, i get a powerful shot every time. the problem is the noise. its extremely loud, which is to be expected, but its somewhat limiting, since i cant fire it at night and the neighbors dont like it when i fire it too much at all.

the solution: a silencer. It is going to be on a 6' x 2" barrel, made of two feet of four inch pipe with a bell reducer on each end. i could change this, shorter would be easier to do than longer, but that is what i have cut. what i'm wondering is what to put in it to absorb the sound, how many holes (if any) to put on the outside of the silencer and in the barrel. any suggestions would be appreciated, especially from personal experience.
thanks

i have no experience, but i saw somewhere said that the stuff in furnus filters works ok

yeah, i've looked at all the related forums, and they helped, but i'm looking for any suggestions. my current plan is to have a bunch of holes in the barrel, and a few in the outside of the silencer. I'm thinking i'll stuff old socks and clothes in it.

First,Put as many holes you can in the pipe that is over the barrel then wrap it in a layer of mosquito netting(or something really porous).Next,get some synthetic pillow fill and wrap a layer of that around the pipe, followed by a layer cotton balls or any of those cotton ball type sheets.Finally wrap a piece of T shirt around to keep everything together.Put that in your outer piece of pipe and you have a silencer. Hope that helps

I don' think you should put holes in the silencer it self.
Only in the barrel.

Okay, I didn't read the second post of his.I was under the impression that he was making an add-on to the barrel.So yeah,He shouldn't put the holes in the outside.But put as many as holes as possible in the barrel.

Or make a pnuematic

you should put holes in the silencer itself if you are using that kind of silencer.....

the purpouse of a silencer is to slow down the expanding gasses

im modern firearms, the supressor is made of baffles placed down the silencer, giving it a HUGE volume. heres a link incase you need it

http://en.wikipedia.org/wiki/Image:Maxi ... rawing.png

you dont need the elaborate coily things, just straight baffles work fine. just make sure they can take the grunt of getting hit by a potato........... (paper is NOT a good idea)

it may not seem like it will work, but it does, i did it for my Airsoft Sniper rifle (gas rifle, VERY loud) and it is now a barely audible (pop) from 50 feet.

ShowNoMercy wrote:Or make a pnuematic

Pneumatics are still loud mate, im doing a how to on a small bore silencer later on today

I would just make lots of holes in the end of the barrel/silencer and maybe put some cotton cloth around it all

have a look here and scroll down for a suitable design that should suit your needs.

would it work if i didn't use baffles? i'd like to avoid that if i can, they look like a pain to make.
and i already made a pneumatic, a coaxial cannon with barrel sealing piston and interchangeable barrels. and its still fairly loud, tho nothing like the propane cannon.
if i use the design of filling the space with cotton balls, t shirts, etc., is there some way to tell how many holes to have on the outside?

how big is your barrel? make the can out of 4 inch PVC and make the baffles out of 3 inch endcaps................... with BIGGG holes in them. but whatever, it will still work.

a longer barrel is cheaper eaiser and legal

meatballs wrote:would it work if i didn't use baffles? i'd like to avoid that if i can, they look like a pain to make.

It would still work, but not as effectively - is it such a big deal to cut a few circles out of ply or some other sheet material?

if i use the design of filling the space with cotton balls, t shirts, etc., is there some way to tell how many holes to have on the outside?

No need to fill it with anything, though in the case of a combustion cannon I'd stay away from combustible materials like cotton balls and use wire mesh/steel wool instead. Also, holes in the outside tube BAD! - the idea here is to contain the gasses so they can lose pressure before they leave the muzzle, and making holes on the outside of the can defeats this purpose.