Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 56 users online :: 4 registered, 0 hidden and 52 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Safety of malleable iron

Post questions and info about hybrid (compressed gas with fuel) powered cannons here. This includes discussion about fuels, ratios, ignition systems, build types, safety, and anything else relevant.
Sponsored 
  • Author
    Message

Unread postAuthor: nivekatoz » Sat Jun 21, 2008 8:46 pm

If you capped off both ends of a sch 40 black iron pipe and filled it with black powder ,the caps will blow off and strip the threads before the pipe bursts..I have seen solw motion viedo of this.. On the other hand, I don't know how much powder was used..But still it looked powerfull. Im no expert.
  • 0


nivekatoz
2nd Lieutenant
2nd Lieutenant
 
Posts: 237
Joined: Sat Nov 25, 2006 7:05 pm
Reputation: 0

Unread postAuthor: tyrant_bb » Sun Jun 22, 2008 12:01 am

DYI: Well, you said 1/2" steel coupling...but then you said malleable iron (or same thing?)...anyway wow that makes me feel a lot safer.

nivekatoz: Are the endcaps made of malleable or black iron?

This is unrelated, but if I wanted to drill a hole for 1/4" NPT fitting, what size would I drill?
  • 0

Last edited by tyrant_bb on Sun Jun 22, 2008 12:03 am, edited 1 time in total.

tyrant_bb
Private
Private
 
Posts: 18
Joined: Thu Feb 28, 2008 5:18 pm
Reputation: 0

Unread postAuthor: frankrede » Sun Jun 22, 2008 12:01 am

spudfarm wrote:i say this once again.

a soda bottle can hold 150psi. then you think of the wall thickness and the soft plastic used in them. do you trust the fittings for 14.6 as high burst pressure as the bottle? (they also has less surface area aswell as the double wall thickness when something is threaded into or outside them)
According to your logic, then cell core abs is a great material to use in pneumatics!
  • 0

Current project: Afghanistan deployment
User avatar
frankrede
Lieutenant General
Lieutenant General
 
Posts: 3220
Joined: Thu Jul 20, 2006 9:47 pm
Reputation: 0

Unread postAuthor: tyrant_bb » Sun Jun 22, 2008 12:06 am

Haha I heard that, but I actually tried this with a 2 liter soda bottle...I used a pop in schrader valve and sealed it with epoxy. At 60 psi, the bottle rips around the valve and flies across the room. Probably some mistake I made though.
  • 0


tyrant_bb
Private
Private
 
Posts: 18
Joined: Thu Feb 28, 2008 5:18 pm
Reputation: 0

Unread postAuthor: DYI » Sun Jun 22, 2008 10:19 am

According to your logic, then cell core abs is a great material to use in pneumatics!


How's that? Cellular core pipe is full of air bubbles, so you can't apply the same guesstimates that you can with a solid material.

The coupling I mentioned earlier was malleable iron, just to clarify. I tried the same setup earlier with black powder, and it held together just fine, although I still wouldn't want to be within a hundred feet of it when it went off.
  • 0

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.
User avatar
DYI
Lieutenant General
Lieutenant General
 
Posts: 2861
Joined: Sat Jul 07, 2007 8:18 pm
Location: The People's Republic of Canuckistan
Country: Turks and Caicos Islands (tc)
Reputation: 9

Unread postAuthor: SpudFarm » Sun Jun 22, 2008 11:12 am

i think all the "magic dust" talk should be stopped here before someone get a nice slap by a mod.

frank: cell core is just fine for everything. if you don't put more pressure in it than 5psi.

one more note about this. you know these balls? i bursted one and it held up to 65psi.
  • 0

"Made in France"
- A spud gun insurance.
User avatar
SpudFarm
Donating Member
Donating Member
 
Posts: 2563
Joined: Sat Nov 04, 2006 9:39 am
Location: Norway Trondheim area
Reputation: 0

Unread postAuthor: Gippeto » Sun Jun 22, 2008 11:17 am

Some information about iron. There is a table lower down which gives tensile strengths.

Why guess when you can know?

http://en.wikipedia.org/wiki/Cast_iron
  • 0

"It could be that the purpose of your life is to serve as a warning to others" – unknown

Liberalism is a mental disorder, reality is it's cure.
User avatar
Gippeto
Donating Member
Donating Member
 
Posts: 2393
Joined: Sat Jan 19, 2008 10:14 am
Location: The Great White North...Canada eh!
Reputation: 11

Sponsored

Sponsor
 


Unread postAuthor: SpudFarm » Sun Jun 22, 2008 11:27 am

i can't have done that right..
  • 0

Attachments
2 fittings.jpg
whooha!
2 fittings.jpg (30.12 KiB) Viewed 507 times
"Made in France"
- A spud gun insurance.
User avatar
SpudFarm
Donating Member
Donating Member
 
Posts: 2563
Joined: Sat Nov 04, 2006 9:39 am
Location: Norway Trondheim area
Reputation: 0

Unread postAuthor: Gippeto » Sun Jun 22, 2008 12:24 pm

Your wall thickness seems too much. I prefer to use the thinnest section when calculating burst/yield pressures.

Usually the wall thickness at the deepest part of the thread.
  • 0

"It could be that the purpose of your life is to serve as a warning to others" – unknown

Liberalism is a mental disorder, reality is it's cure.
User avatar
Gippeto
Donating Member
Donating Member
 
Posts: 2393
Joined: Sat Jan 19, 2008 10:14 am
Location: The Great White North...Canada eh!
Reputation: 11

Unread postAuthor: SpudFarm » Sun Jun 22, 2008 12:27 pm

but the threads helps also. (i may did it wrong since i usally uses mm)
  • 0

"Made in France"
- A spud gun insurance.
User avatar
SpudFarm
Donating Member
Donating Member
 
Posts: 2563
Joined: Sat Nov 04, 2006 9:39 am
Location: Norway Trondheim area
Reputation: 0

Unread postAuthor: Gippeto » Sun Jun 22, 2008 12:35 pm

I don't know about the fittings and pipe that you have in Norway, but the stuff I use still leaves more than one thread to atmosphere when tightened.

That makes it the thinnest section, and the thickness to use for calculations.

You are ALWAYS better to err on the safe side.

.2" = 5.08mm
  • 0

"It could be that the purpose of your life is to serve as a warning to others" – unknown

Liberalism is a mental disorder, reality is it's cure.
User avatar
Gippeto
Donating Member
Donating Member
 
Posts: 2393
Joined: Sat Jan 19, 2008 10:14 am
Location: The Great White North...Canada eh!
Reputation: 11

Unread postAuthor: SpudFarm » Sun Jun 22, 2008 12:38 pm

i messure my fittings tomorrow
  • 0

"Made in France"
- A spud gun insurance.
User avatar
SpudFarm
Donating Member
Donating Member
 
Posts: 2563
Joined: Sat Nov 04, 2006 9:39 am
Location: Norway Trondheim area
Reputation: 0

Unread postAuthor: frankrede » Sun Jun 22, 2008 2:33 pm

DYI wrote:
According to your logic, then cell core abs is a great material to use in pneumatics!


How's that? Cellular core pipe is full of air bubbles, so you can't apply the same guesstimates that you can with a solid material.

The coupling I mentioned earlier was malleable iron, just to clarify. I tried the same setup earlier with black powder, and it held together just fine, although I still wouldn't want to be within a hundred feet of it when it went off.
Cellcore abs is actually 2 thin layers of plastic, not to different than the plastic of soda bottles, and might even be stronger with a hard foam core.
  • 0

Current project: Afghanistan deployment
User avatar
frankrede
Lieutenant General
Lieutenant General
 
Posts: 3220
Joined: Thu Jul 20, 2006 9:47 pm
Reputation: 0

Unread postAuthor: Maniac » Sun Jun 22, 2008 4:24 pm

ne more note about this. you know these balls? i bursted one and it held up to 65psi.


Is that true, my dad is a personal trainer and he has like 5 of those balls ghetto pneumatic award here I come.
  • 0

Coodude26 wrote:
People who laugh really hard at stuff that pisses you off/you getting hurt, who then say "I'm sorry, I can't stop" but you know they easily could.

Mr.C: That's not as easy as you think. It's like me kicking you in the balls and telling you to stop crying.
User avatar
Maniac
Lieutenant Colonel
Lieutenant Colonel
 
Posts: 496
Joined: Tue Oct 23, 2007 5:55 pm
Location: Right behind you
Reputation: 0

Unread postAuthor: SpudFarm » Sun Jun 22, 2008 5:04 pm

yeah it is true but it gave a pretty decent bang and blew the grass away.

and don't use it over 20psi since it can burst when you touch it.
  • 0

"Made in France"
- A spud gun insurance.
User avatar
SpudFarm
Donating Member
Donating Member
 
Posts: 2563
Joined: Sat Nov 04, 2006 9:39 am
Location: Norway Trondheim area
Reputation: 0

PreviousNext

Return to Hybrid Cannon Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot]

Reputation System ©'