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 62 users online :: 5 registered, 0 hidden and 57 guests


Most users ever online was 218 on Wed Dec 07, 2016 6:58 pm

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

The Team
Administrators
Global Moderators
global_moderators.png CS

Does your pneumatic Air Gun has a leak?

Come find a how-to on how to do something, or come write your own for other people.
Sponsored 
  • Author
    Message

Does your pneumatic Air Gun has a leak?

Unread postAuthor: nadjatee1996 » Fri Jan 28, 2011 10:24 am

Well, mine did, and I found an easy solution, this can be done with a sink or a fish tank, just stick the thing in there, pump a few times and note where the bubbles are coming from, then epoxy that baby in!
  • 0


nadjatee1996
Sergeant Major
Sergeant Major
 
Posts: 185
Joined: Mon Jan 03, 2011 7:20 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Fri Jan 28, 2011 10:29 am

Also: Image
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: nadjatee1996 » Fri Jan 28, 2011 11:03 am

HEY, SOME PEOPLE MIGHT NOT KNOW >.<
  • 0


nadjatee1996
Sergeant Major
Sergeant Major
 
Posts: 185
Joined: Mon Jan 03, 2011 7:20 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Fri Jan 28, 2011 11:11 am

nadjatee1996 wrote:HEY, SOME PEOPLE MIGHT NOT KNOW >.<


If so, they can't be trusted with projectile launchers ;)
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: qwerty » Fri Jan 28, 2011 11:34 am

Jack will get angry about this but... My epoxy (UniBond metal stuff) never seals.

I always end up using endcaps of some sort instead.
No matter how much i sand and how much i layer it on i will allways get a leak.
  • 0

I visit occasionally to make unrelated posts.
User avatar
qwerty
Colonel
Colonel
 
Posts: 677
Joined: Sun Apr 12, 2009 2:16 am
Location: Evesham, Worcs
Country: United Kingdom (uk)
Reputation: 0

Unread postAuthor: Gaderelguitarist » Fri Jan 28, 2011 11:42 am

The SOLUTION is to simply build the system correctly from the start.
  • 0

so many muchness
User avatar
Gaderelguitarist
Colonel
Colonel
 
Posts: 580
Joined: Sat Aug 16, 2008 9:56 pm
Location: Columbia, MD
Reputation: 0

Unread postAuthor: FighterAce » Fri Jan 28, 2011 11:43 am

If you have a hiss... go back to the hardware store and ask the gentleman how to use the PTFE tape....

If you can't hear anything but see bubbles... apply more PTFE, check if the fitting/pipe is tightened all the way and check for defects in the threads.

I wonder how you seal a leak on a cannon thats put together with epoxy... if you put some epoxy on the outside, the pressure would concentrate in that area and blow the epoxy patch right?
  • 0

“The combined synergy of a man and rifle is matchless.
The steadiness of hand, the acuity of vision and finally
the art of knowing how to make the rifle an extension of the
body all equate to the ultimate synthesis of man and machine.”
User avatar
FighterAce
1st Lieutenant
1st Lieutenant
 
Posts: 286
Joined: Fri Oct 23, 2009 1:28 pm
Location: Croatia/Zagreb
Country: Croatia (hr)
Reputation: 1

Sponsored

Sponsor
 


Unread postAuthor: POLAND_SPUD » Fri Jan 28, 2011 11:51 am

The SOLUTION is to simply build the system correctly from the start.
lol you heard the man... go get some threaded fittings
  • 0

Children are the future

unless we stop them now
User avatar
POLAND_SPUD
Chief of Staff
Chief of Staff
 
Posts: 5405
Joined: Sat Oct 13, 2007 4:43 pm
Country: Israel (il)
Reputation: 10

Unread postAuthor: Hubb » Fri Jan 28, 2011 6:23 pm

I'm not exactly sure that putting a 3' long chamber into a sink or fish tank is going to be as simple as you state. The better solution is just to use soapy water. Spray it on and note where the bubbles are at, then fix it.
  • 0

User avatar
Hubb
Major General
Major General
 
Posts: 2390
Joined: Mon May 28, 2007 8:39 am
Location: South Georgia
Reputation: 2

Unread postAuthor: jackssmirkingrevenge » Fri Jan 28, 2011 11:57 pm

qwerty wrote:Jack will get angry about this but... My epoxy (UniBond metal stuff) never seals.


Jack is not angry, just upset :cry:

I put this one together using Araldite only, which I presume has similar properties to Unibond, at it held 800 psi without leaking.

This was for a small diameter project though, for bigger stuff at high pressure I would recommend something tougher and pourable.
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: qwerty » Sat Jan 29, 2011 2:56 am

Threaded fittings = Big and bulky

Oh, i've tried Araldite many times, it's even worse.

Have you ever used the metal putty stuff?

Oh, and i can use PTFE tape, this is for a very small pistol sized gun.
  • 0

I visit occasionally to make unrelated posts.
User avatar
qwerty
Colonel
Colonel
 
Posts: 677
Joined: Sun Apr 12, 2009 2:16 am
Location: Evesham, Worcs
Country: United Kingdom (uk)
Reputation: 0

Unread postAuthor: POLAND_SPUD » Sat Jan 29, 2011 8:30 am

Threaded fittings = Big and bulky
well yes and no
:wink:

Sure some iron fittings are a lot bulkier than they have to be but you're not limited to them only. Last time I checked brass fittings were just a little bit more expensive than cast iron ones.

It's the best thing for high pressures and it makes your gun serviceable in just a few seconds.

lol let's see what alternatives do we have...
PVC is good for ~ 100-150 psi, and it just isn't up to the job.

Welding is not an option for most users... well unless you're a qualified welder that has built thousands of pressure vessels in his life

Epoxy is just like welding... seems cool at first but unless you are jsr you can't be sure that your castings can handle more than 300 psi, or so

Copper pipes & fittings (soldered) are the only thing that come close to metal threaded fittings (but most copper guns have some threaded fittings anyway)
  • 0

Children are the future

unless we stop them now
User avatar
POLAND_SPUD
Chief of Staff
Chief of Staff
 
Posts: 5405
Joined: Sat Oct 13, 2007 4:43 pm
Country: Israel (il)
Reputation: 10

Unread postAuthor: nadjatee1996 » Sat Jan 29, 2011 12:48 pm

qwerty wrote:Threaded fittings = Big and bulky

Oh, i've tried Araldite many times, it's even worse.

Have you ever used the metal putty stuff?

Oh, and i can use PTFE tape, this is for a very small pistol sized gun.


I used that, it works great, but it has some drawbacks, no leaks though, I found that my leak was at the meeting place of the hose handle and the trigger, epoxying that means that I couldn't fire anymore
  • 0


nadjatee1996
Sergeant Major
Sergeant Major
 
Posts: 185
Joined: Mon Jan 03, 2011 7:20 pm
Reputation: 0

Unread postAuthor: jackssmirkingrevenge » Sat Jan 29, 2011 3:34 pm

qwerty wrote:Oh, i've tried Araldite many times, it's even worse.


I used it to 800 psi, maybe you're doing it wrong?

Have you ever used the metal putty stuff?


Putty isn't really a good idea, you want something less viscous that will flow and really seal and adhere to the material.

POLAND_SPUD wrote:Epoxy is just like welding... seems cool at first but unless you are jsr you can't be sure that your castings can handle more than 300 psi, or so


Even JSR doubts himself sometimes ;)
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Unread postAuthor: nadjatee1996 » Sat Jan 29, 2011 5:21 pm

I used the putty, no leaks, but you gotta press hard on it, and shape it with a wet piece of paper towel
  • 0


nadjatee1996
Sergeant Major
Sergeant Major
 
Posts: 185
Joined: Mon Jan 03, 2011 7:20 pm
Reputation: 0

Next

Return to How-To Guide Database

Who is online

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

Reputation System ©'