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 53 users online :: 4 registered, 0 hidden and 49 guests


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

Registered users: Bing [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

Brazing kills sharders

Post questions and info about pneumatic (compressed gas) powered cannons here. This includes discussion about valves, pipe types, compressors, alternate gas setups, and anything else relevant.
Sponsored 
  • Author
    Message

Brazing kills sharders

Unread postAuthor: john bunsenburner » Sun Nov 30, 2008 12:53 pm

Last night while making my chamber i brazed a tire valve into a hole at the end cap of my iron chamber. When i was done and everything had cooled i inspected the valve and noticed it was broken, i fixed the problem with a checkvalve from a pump which screwed on but i would like to know why the sharder broke and if i could fix it:

The sharder is brazed onto a tapped iron end cap. there is white and black residue on the inside which i noticed after brazing. The rubber at the bottom of the sharder has bin removed and i used a silver based brazing rod with a melting point of 690°C. There was some smoke while soldering but i suspected it was simply the rest of the rubber burning off, which in turn happened. The part which has to be pressed does inoreder to release the pressure inside the bike(or inorder to fill it) moves around freely when i shake it. When i blow into the valve it is slightly easyer to blow than to pull. Pictures will be attached, note it is night time here and i am in underwear incase some one might be disturbed by this i mentioned it now before things being too late:
  • 0

Attachments
Broken valve pics.jpg
These are a few pics i took using my web cam, i hope they help.
Broken valve pics.jpg (24.73 KiB) Viewed 917 times
Last edited by john bunsenburner on Sun Nov 30, 2008 1:36 pm, edited 1 time in total.
"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"-George Will
User avatar
john bunsenburner
Major General
Major General
 
Posts: 1446
Joined: Sun Oct 19, 2008 5:13 am
Reputation: 0

Re: Brazing kills sharders

Unread postAuthor: Gippeto » Sun Nov 30, 2008 1:03 pm

john bunsenburner wrote:Last night while making my chamber i brazed a tire valve into a hole at the end cap of my iron chamber. When i was done and everything had cooled i inspected the valve and noticed it was broken, i fixed the problem with a checkvalve from a pump which screwed on but i would like to know why the sharder broke and if i could fix it... If you need details on what is wrong i could check, just ask me.



DO NOT respond to this post. *** READ it.***

I for one, have had enough of your BS posts.

If you can't put the details in the first post, why should "we" continue to try to help you.

Edit your first post, and put the details in it.

Be PRECISE with your description.

Better yet, include a picture.

I will not be responding to your posts in the future unless you figure this out.

I encourage other members to do the same.

Enough IS enough. :x
  • 0

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: Hotwired » Sun Nov 30, 2008 1:06 pm

The schrader valve is a metal tube threaded inside and out with a small sprung poppet valve that screws down inside it.

The metal outer tube will not take notable damage from being brazed, the poppet valve insert will however, the spring inside may lose its strength and the seals will certainly melt or burn.

You can remove the poppet valve from inside the stem with a special tool or faff about with a pair of tweezers.
  • 0

User avatar
Hotwired
Lieutenant General
Lieutenant General
 
Posts: 2599
Joined: Fri Oct 13, 2006 5:51 am
Location: UK
Reputation: 0

Unread postAuthor: john bunsenburner » Sun Nov 30, 2008 1:06 pm

Ok sorry, i just dont have a camara at had, im really sorry, ill suply as much detail as i can in an edit, and maybe i can use a webcam to make a picture. sorry...
  • 0

"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"-George Will
User avatar
john bunsenburner
Major General
Major General
 
Posts: 1446
Joined: Sun Oct 19, 2008 5:13 am
Reputation: 0

Re: Brazing kills sharders

Unread postAuthor: Ragnarok » Sun Nov 30, 2008 1:17 pm

I'm not sure that's fair Gippeto, he doesn't necessarily know what information is needed - he's new to the hobby, he hasn't learnt about all of the pitfalls yet. I'd probably have to ask what I should be looking for to diagnose the problem if I had an electronics problem, because I don't know electronics.
Indeed, you asked about why your chronograph wasn't working the other day, because you didn't know what was causing the problem.

Like you, he knows there's a problem, but he doesn't know what the cause is. That's what the forums are for, sorting out these things. And anyway, there's enough information to answer his question there.

john bunsenburner wrote:but i would like to know why the sharder broke and if i could fix it.

Because you exposed it to the heat of brazing - there are rubber parts in those that can and will be destroyed by high temperatures.

No, it probably can't be fixed, although you could try again with another schrader, but this time, extract the internal parts before you braze it, then put it together after it's all cooled.
If you get a set of long nosed pliers, then you should be able to reach into the end of the valve and unscrew/remove the heat-vulnerable parts. Screw them back in again when you're done.
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Unread postAuthor: twizi » Sun Nov 30, 2008 1:37 pm

Ragnarok right the rubber seals the schrader if it heated above 110 i would think it would deform and not seal
  • 0

User avatar
twizi
Colonel
Colonel
 
Posts: 511
Joined: Thu Nov 27, 2008 9:04 pm
Location: up yours
Reputation: 0

Unread postAuthor: john bunsenburner » Sun Nov 30, 2008 1:43 pm

Look at my edited post, i might be a noob but i have too much pride to let people call me one, i hope the new version supplys all information needed, for you gipetto, if it does not then go screw your self, it may sound harsh but i told you all i know in a third language of mine during an influenza infection that has been lasting two weeks now, i barely have the power to stand up to get a dring from my fridge but i had to demonstrate that i could do better, thank you and i hope you like it and that you decide that reading a noobs post is worth it and that you respond to my post.


@rag: Is there something besides a checkvalve, like a second sharder or something that i could screw ontop of the broken sharder and have a funtioning valve or not? could i replace the rubber seals?
  • 0

"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"-George Will
User avatar
john bunsenburner
Major General
Major General
 
Posts: 1446
Joined: Sun Oct 19, 2008 5:13 am
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: Ragnarok » Sun Nov 30, 2008 1:46 pm

john bunsenburner wrote:@rag: Is there something besides a checkvalve, like a second sharder or something that i could screw ontop of the broken sharder and have a funtioning valve or not?

If you have a second schrader, you might be able to swap the internals of them over and fix the first one.
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Unread postAuthor: john bunsenburner » Sun Nov 30, 2008 1:50 pm

I have a second one, what exactly do i have to take out i am a little unsure about it and i do not feel like breaking another sharder, is there an instructable some where or yould you explain and elaborate a little and add some detail so that both gipetto and i are happy(sorry i could not resist that little joke there)
  • 0

"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"-George Will
User avatar
john bunsenburner
Major General
Major General
 
Posts: 1446
Joined: Sun Oct 19, 2008 5:13 am
Reputation: 0

Re: Brazing kills sharders

Unread postAuthor: THUNDERLORD » Sun Nov 30, 2008 1:54 pm

Ragnarok wrote:I'm not sure that's fair...


Me too, as it made me think harder about ways I'd fuel a mini-hybrid.
(Especially since I've considered pre-mixes).
I plan to situate the fuels and fill valve in a spot below and forward on the barrel but it's much better to avoid the possibilities...

I'm surprised since pumps generate heat usually by compression alone.

@rag: Is there something besides a checkvalve, like a second sharder or something that i could screw ontop of the broken sharder and have a funtioning valve or not?


Not directed at me but you could possibly grind/cut the top of a metal valve cap (to make a coupling) then cut the base off another and epoxy the threads and screw them together (before it dries) (?).

EDIT: Dang I type slow! The internals unscrew by turning the flat sides of the pin. once you unscrew it it's pretty self explanatory.
I thought it had broken in half but was already welded maybe. Good luck on it. 8)
  • 0

Last edited by THUNDERLORD on Sun Nov 30, 2008 1:58 pm, edited 1 time in total.
-----SPEED,STRENGTH, AND ACCURACY.-----
"Procrastination" is five syllables for "Sloth".
Theopia 8)
Born To Be Alive!

THUNDERLORD
Major General
Major General
 
Posts: 1264
Joined: Fri Mar 28, 2008 1:42 pm
Reputation: 0

Unread postAuthor: SEAKING9006 » Sun Nov 30, 2008 1:56 pm

That's why I asked for a pack of threaded 1/4 MPT shraeders for christmas. I am getting tired of using expensive quick-connect and ball valve setups. I don't have the- wait, yes I do. Here's the link for 1/4 NPT threaded schraeder valves.
  • 0

Completed projects:
CA1 SMSS Basic Inline
CA3 PDAB Airburst Cannon

Current Project: Bolt action rifle (25x140mm + 1in shot)

SEAKING9006
Colonel
Colonel
 
Posts: 734
Joined: Mon Jun 23, 2008 3:20 pm
Location: Texas
Reputation: 0

Unread postAuthor: john bunsenburner » Sun Nov 30, 2008 1:57 pm

I am not sure what you mean by your first part of the post but i will ignore it as a wierd joke and i do not like improvises glued together wierd joints, i prefer the meathod recomended by the guy who posted before you.
  • 0

"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"-George Will
User avatar
john bunsenburner
Major General
Major General
 
Posts: 1446
Joined: Sun Oct 19, 2008 5:13 am
Reputation: 0

Unread postAuthor: THUNDERLORD » Sun Nov 30, 2008 2:15 pm

john bunsenburner wrote:I am not sure what you mean by your first part of the post but i will ignore it as a wierd joke and i do not like improvises glued together wierd joints, i prefer the meathod recomended by the guy who posted before you.


If that was directed at me?
I made no wierd joke, just explained this post caused me to think that for safety in fueling a hybrid some other valve should be used since heat will affect the shraeder valve (without the heat factor they could withstand high pressure).

I had added an edit, but Like I stated, I type slow.

Now for the weird joke:
... note it is night time here and i am in underwear incase some one might be disturbed by this i mentioned it now before things being too late:


:lol: I'll just drop it, it's TMI, heck I understand, when I look at some designs just guess where my hand is (Not really but it's a funny wierd joke though right?)... :P 8)
  • 0

-----SPEED,STRENGTH, AND ACCURACY.-----
"Procrastination" is five syllables for "Sloth".
Theopia 8)
Born To Be Alive!

THUNDERLORD
Major General
Major General
 
Posts: 1264
Joined: Fri Mar 28, 2008 1:42 pm
Reputation: 0

Unread postAuthor: john bunsenburner » Sun Nov 30, 2008 2:24 pm

Ok lets drop our little wierd joke act, and i will fix the shader as soon as i put a pair of pants over my boxers tomorrow morning (or like most of the time i wont and i will dremel and weld in underwear which looks very silly)...haha
  • 0

"Did you ever stop to think that out of the seven deadly sins envy is the only one which doesn't give the sinner even momentary pleasure"-George Will
User avatar
john bunsenburner
Major General
Major General
 
Posts: 1446
Joined: Sun Oct 19, 2008 5:13 am
Reputation: 0

Unread postAuthor: starman » Sun Nov 30, 2008 2:47 pm

You obviously melted the rubber sealing parts inside the schrader. Most of the non-tire type schraders are threaded so you should plan to drill and tap or cement (JB Weld) and not braze your schrader.
  • 0

User avatar
starman
Donating Moderator
Donating Moderator
 
Posts: 3041
Joined: Wed Dec 12, 2007 12:45 am
Location: Simpsonville, SC
Reputation: 0

Next

Return to Pneumatic Cannon Discussion

Who is online

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

Reputation System ©'