Sealing joints

Cannons powered by pneumatic pressure (compressed gas) using a valve or other release.
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john bunsenburner
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Ok i just got my self a propane soldering thing. It holds great but is not air tight. I tried using silicone but ti pops off at higher pressures and buying 100ml of epoxy for 70bucks (switzerland...) puts me off. What could I use to seal my joint? and O-ring dont work becuse i dont have a lathe. Waht suggestions does every one here have? After all this muct be a common problem.
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jackssmirkingrevenge
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What could I use to seal my joint?
A lick of saliva usually works great ;)
hectmarr wrote:You have to make many weapons, because this field is long and short life
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SpudUke5
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jackssmirkingrevenge wrote:
What could I use to seal my joint?
A lick of saliva usually works great ;)
Only you :roll: :lol:
It holds great but is not air tight
What are you referring to?

Um, i really dont know what else to tell you if you cant use epoxy.
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Sticky_Tape
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Does it have a ring of silver stuff (solder) on the inside of the joint where you put the pipe in? All you have to do with those joints is take a torch to them with the pipe pushed in that melts the solder bonding the pipe to the joint. BTW Ragnarok use one of those joints for the breech on HEAL I think I think.
You can tell how awesome a cannon is by the pressure used.
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john bunsenburner
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Well the thing is im making my chamber, which will sit in my back pack, so im soldering a silicone tube fitting to my iron pipe chamber. The hole i managed to make was not quite the right diameter so i soldered the fitting on so it would just stay in the middle. I can hit it with a hammer but when i blow into it the air leaks out of the jont. I put silicone sealing stuff around it which is messy but it holds(right now atleast!) is there any better way? Ak for a diagram or picture is you need one.
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john bunsenburner
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I am waiing and hoping for a reply to this topic. I really need to seal my joints well and im sure that I am not the only person that needs to do so. An answer like use epoxy is pefectly fine( eventhough im not quite sure what kind to use then). Just tell me what you use. Thank you
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What are the materials you are soldering together, and what are you using for solder. ("silicone tube fitting" is it brass?)

Did you use flux?

Soldering brass to iron or steel should not present a problem. Re-heat the joint, take it apart, and clean the pieces REALLY well.

Flux both pieces, assemble, and solder.

Epoxy, silicone, etc. should not be required.

A little present for you :wink:

http://www.easy2diy.com/cm/easy/diy_ht_ ... d=35749917
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john bunsenburner
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OK im conecting brass to iron and then brass to copper and then copper to alli, what should i use and yes i use flux when soldering
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Fnord
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From past experiences I should let you know that malleable iron is sometimes hard to solder. Take some heavy sandpaper to it until it's shiny.
...and then copper to alli
Aluminum?
Don't expect to solder aluminum well.
It IS possible, but without special solder the results will be crappy looking and probably not airtight.
Image
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john bunsenburner
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so how CAN i connect them all up, it was stupid of me to use so many different metals but that is what i had at hand, and the copper was to expensive as a barrel so...Should i buy(make muahahaha) epoxy or should i get special solder or a welding machine...im waiting for replys :wink:
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Use epoxy. (JB weld, Araldite or something similar)

Use paint thinner or other solvents to clean the iron fittings first.

Sand everything to roughen it and give the epoxy something to hold on to.

Follow the directions on the package for mixing and cure times.
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john bunsenburner
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ok thank you, ill need a while to to get epoxy an dfinish my gun, i got into a fist fight while a date so ya...and ill have some fun this week end so, ill need a while. If you have other ideas ill be thankful
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Ragnarok
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Sticky_Tape wrote:BTW Ragnarok use one of those joints for the breech on HEAL I think I think.
I did, but I gouged the ring of solder out of one half of it first - the side the sliding barrel would seat into of course.

The reason I used that particular fitting is that in the UK pipe sizing, 22mm solder-ring fittings fit very snugly inside 28mm pipe (the pipe I used for the outer parts of the breech loader), so it was a way of allowing a continuous 22mm size for the air flow (No diameter changes = more efficent), but still fitting the 28mm pipe firmly in place for the breech lever to lock into.

Bit of a late reply, but I got there at last.
Does that thing kinda look like a big cat to you?
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