Hello guys,
i just want to know wich of the 2 spudguns type ( combustion and pneumatic) is the safest?
who had the most chance of blowing up?
im 13, had 5 pneumatics( yes i am a maniac) and i want to try combustion but my father dont want.
maybe if you, experts of spudguns, says then combustion is safest as pneumatic, will convince him. but dont lie.
and yes my english sucks.
wich is the safest? PLZ ANSWER
-
SpudFarm
- First Sergeant 3
- Posts: 2571
- Joined: Sat Nov 04, 2006 9:39 am
- Location: Norway Trondheim area
first off your english does suck but that is not a problem aslong as we understand you, and i does.
the safest type of guns is combustions no doubt. tell you father that they make absolute max 100psi and your pneumatic uses that, but has to hold it for a long time..
if you say that you will be allowed
the safest type of guns is combustions no doubt. tell you father that they make absolute max 100psi and your pneumatic uses that, but has to hold it for a long time..
if you say that you will be allowed
"Made in France"
- A spud gun insurance.
- A spud gun insurance.
Assuming all else is equal, the combustion is likely safer, although you will also struggle to get as much power from it.
Combustions only generate peak pressures of the order of 60-80 psi when they're being fired, unlike a pneumatic which is constantly under pressure, often 100 psi or more.
Drop a cannon that's under pressure, and the results could be nasty.
Combustions do generate shock pressure and heat which does affect the safe pressures, but in a well made cannon made from pressure rated components, that is of little concern.
While I'm here, I'll make the point that combustions do not work on "explosions", although a lot of people seem to labour under the misconception that they do.
They work on rapid burning (deflagration, not detonation) of whatever fuel you have, which heats the gases in the chamber to produce a pressure.
If your father is so worried about such "explosions", suggest he gets rid of his car - it's engine works on exactly the same principles, so if he's that worried about such things, obviously it'll have to go.
Combustions only generate peak pressures of the order of 60-80 psi when they're being fired, unlike a pneumatic which is constantly under pressure, often 100 psi or more.
Drop a cannon that's under pressure, and the results could be nasty.
Combustions do generate shock pressure and heat which does affect the safe pressures, but in a well made cannon made from pressure rated components, that is of little concern.
While I'm here, I'll make the point that combustions do not work on "explosions", although a lot of people seem to labour under the misconception that they do.
They work on rapid burning (deflagration, not detonation) of whatever fuel you have, which heats the gases in the chamber to produce a pressure.
If your father is so worried about such "explosions", suggest he gets rid of his car - it's engine works on exactly the same principles, so if he's that worried about such things, obviously it'll have to go.
Does that thing kinda look like a big cat to you?
There's no real reason to fret about it.Demon wrote:thanks guys but my father does not want, i dont know why, thanks for had tryed.
My parents don't really want me playing with propane, which is part of the reason I don't really do combustions, so to keep them moderately happy, I do pneumatics instead.
Problem for them is, that they don't realise the pneumatics I build have the power of a combustion a good 4 or 5 times their size.
Does that thing kinda look like a big cat to you?
-
trollhameran
- Corporal
- Posts: 515
- Joined: Tue Dec 04, 2007 5:41 pm
My mum isnt that keen on either, but she'd rather i make pneumatic, probably because I burnt my eyelashes off once. But my dad isnt really bothered as long as I only take his scrap plumbing parts.
-
trollhameran
- Corporal
- Posts: 515
- Joined: Tue Dec 04, 2007 5:41 pm
I make up for it with non spudding related incidents though
As amusing as that idea might be, lying to your parents is not usually a good idea, especially when they're very likely to find out the truth.SpudFarm wrote:just tell him it is a pneumatic that runs on pressurized propane
Does that thing kinda look like a big cat to you?
Well, for one, there are no explosive alkanes, they're all quite stable.
Secondly, the obvious "lack of constant pressure" thing, and of course the fact that in a normal combustion spudgun, the pressure is almost always lower than in a pneumatic.
If you build two with the same materials, and use the pneumatic at full compressor pressures of at least 120 psi, it should usually fail first. A catastrophic failure is bad for either one, but that's the nature of these things.
In pneumatic vs. combustion, combustion should always win in the end, simply because you don't need to precharge to the full firing pressure and temperature. You cut gas consumption by a factor of at least 6, and a lot more in a well built hybrid.
So, combustions are relatively safer than pneumatics (due to the decreased pressure duration) at the same pressure, and have much lower gas consumption for better performance, once again at the same pressure. There are no explosives involved, as the mixture only becomes flammable when its two components (oxygen and propane in this case) are mixed in very precise proportions (propane has a flammability range of less than 10% in air). Unless you only want low-powered launchers for entertainment, the choice is pretty clear.
Secondly, the obvious "lack of constant pressure" thing, and of course the fact that in a normal combustion spudgun, the pressure is almost always lower than in a pneumatic.
If you build two with the same materials, and use the pneumatic at full compressor pressures of at least 120 psi, it should usually fail first. A catastrophic failure is bad for either one, but that's the nature of these things.
In pneumatic vs. combustion, combustion should always win in the end, simply because you don't need to precharge to the full firing pressure and temperature. You cut gas consumption by a factor of at least 6, and a lot more in a well built hybrid.
So, combustions are relatively safer than pneumatics (due to the decreased pressure duration) at the same pressure, and have much lower gas consumption for better performance, once again at the same pressure. There are no explosives involved, as the mixture only becomes flammable when its two components (oxygen and propane in this case) are mixed in very precise proportions (propane has a flammability range of less than 10% in air). Unless you only want low-powered launchers for entertainment, the choice is pretty clear.
Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
Ehhh I wouldn't put forward a "which would catastrophically fail first under normal use" comparison.
Built properly the answer is irrelevant because they won't.
A combustion of the same size as a pneumatic has less power and in that respect it is safer.
Built properly the answer is irrelevant because they won't.
A combustion of the same size as a pneumatic has less power and in that respect it is safer.
Many parents get frightened when they hear the words "fuel" and "combustion". They imminently seem to think OMG explosion!
Point out to them that it is a deflagration and not a detonation, easier said:it burns, it does not explode.
Since it just burns, there are no dangerous "rip stuff to pieces" shockwaves.
Furthermore, the pressure is limited and lasts for a short time.
Pneumatics though, are usually more reliable and do not involve high temperatures.
Any well-built spudgun is NOT dangerous. The person using it can be.
Point out to them that it is a deflagration and not a detonation, easier said:it burns, it does not explode.
Since it just burns, there are no dangerous "rip stuff to pieces" shockwaves.
Furthermore, the pressure is limited and lasts for a short time.
Pneumatics though, are usually more reliable and do not involve high temperatures.
Any well-built spudgun is NOT dangerous. The person using it can be.
Uh... Why not? They'll all fail eventually under continuous use, whether it takes one shot or 400 years.Ehhh I wouldn't put forward a "which would catastrophically fail first under normal use" comparison.
It's a given that anything which is properly built will not fail in its operational lifetime, so why include that fact?
Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.