Pnuematic Related - A few questions I need help with.

[Mitchza89]

G'day fellow spud chuckers. I'm finally making my dream marble gun. It's all gonna be out of copper but I don't have access to the tools so solder it... I was gonna go for compression fittings but 1'' compression is pretty damn dear so I'm gonna go for epoxy.

Question time...

1. Is it safe to epoxy a gun? I plan on using this thing at a reasonable pressure (160-250...Depends how long it takes me to use my homemade pump and how tired I get...)

2. What's the max output of a fridge compressor used as a pump? I see quite a few of the European spudders use it. BTB uses one and god only knows, he's the master of high psi!

3. Does anyone in Aus know where I can hire a copper pipe bender from? I'm thinking maybe Bunnings or something....

Thanks alot everyone,

Mitch.

[jook13]

I have a fridge pump and have taken it to about 325 or so psi, my guage only goes to 300. It showed no signs of slowing down at those pressures so I assume it would go higher. I have heard they go to around 500, but havent tested it.

It would be much better to soder it. a torch isnt that much money. If anything, they make copper spacific bonding adhesives like http://www.amazon.com/Just-Copper-JFC05 ... 047&sr=8-1

[FordGtMan]

There is this crap called "Just for Copper" and it says it holds up to 500 psi, and the epoxy putty will hold even more.

Edit: Dam, a little slow on that one

[Mitchza89]

Wow that is some serious pressure from that Pump mate, thats crazy....I must get myself one. I wish I knew how they worked though...

Unfortunately, I havn't seen Just For Copper in any shop I might try and get myself some high strength epoxy. Provided I clean everything thoroughly, I reckon it might hold alright.

[THUNDERLORD]

Hello Mitchza89 I would not recomend epoxy for joints. It seems like the larger the pipe the weaker it would be .

I have used epoxy on a copper pipe with an end cap and a strong spring and it was sturdy for that but I just wouldn't trust it.

Besides, It's very simple to solder copper pipe, It would take a bit longer but you could even use a butane torch. Just heat the joints till there cherry reddish color and start applying solder. The heat will draw it into the joint. It will comply with the pressure rating of the pipe also.

I always wondered about HVAC type compressor hooked up as an air compressor until I saw POLAND_SPUD's post in how-to.

You dont need a refrigerator one it could be from any air conditioner, heat pump also. Don't know what psi it would put out maximum but running with refrigerant the "high side" or smaller diameter pipe is usually 300psi.
They are used to compress gas refrigerant back into liquid at high heat normally. and run as long as the unit is running (controlled by thermostat). Well probably not to helpful

EDIT: BTW, most household type compressors are "hermetically sealed" meaning that they can't be opened for repair. So most you will find in junk units will probably be bad. That would be the #1 reason it was trashed. with refrigerators maybe someone just threw it out to get new one or something.

[OuchProgramme]

Hello Mitchza89 I would not recomend epoxy for joints. It seems like the larger the pipe the weaker it would be .

I have used epoxy on a copper pipe with an end cap and a strong spring and it was sturdy for that but I just wouldn't trust it.

A well sanded and cleaned joint bonded with epoxy can hold up to 400 psi.

[jook13]

Wow that is some serious pressure from that Pump mate, thats crazy....I must get myself one. I wish I knew how they worked though...

when I took mine out of the fridge it had 2 little copper pipes sticking out of the side. one is for the air intake and one pushes air out. just figure out how to get power to it and all you need to worry about is getting the right fittings to connect it to your launcher.

like thunderlord just stated, there is a how-to somewhere on this forum that is pretty helpfull.

[THUNDERLORD]

Hello Mitchza89 I would not recomend epoxy for joints. It seems like the larger the pipe the weaker it would be .

I have used epoxy on a copper pipe with an end cap and a strong spring and it was sturdy for that but I just wouldn't trust it.

A well sanded and cleaned joint bonded with epoxy can hold up to 400 psi.

True but if you stick super glue on a hard hat you could hang off tall building also. I wouldn't trust that either. LOL

[Gippeto]

Hey Mitch, What are you cooking up now? I can hardly wait!

Quit being a cheap bugger and buy a torch!


Good info for working with copper;

http://www.copper.org/resources/pub_lis ... ndbook.pdf

[jackssmirkingrevenge]

A well sanded and cleaned joint bonded with epoxy can hold up to 400 psi.

If this wasn't true, none of my launchers would work

Epoxy's fine, as long as it's used well.

[THUNDERLORD]

Well then I trust it more myself.
But isn't it appears more brittle than solder if the gun bangs into something?
Also I don't think it's possible to pass a building inspection with epoxy on pipes for HVAC or Plumbing (against code)
That's what would cause me not to trust it. Not sure though.
Now I have some research to do.

[jackssmirkingrevenge]

I can only speak from experience, all my launchers make extensive use of epoxy-to-PVC joins and are regularly taken to 400 psi+ and i've never had one fail on me.

I do stress the importance however of a) using quality epoxy and b) ensuring the surfaces are correctly prepared by abrading and cleaning before applying the adhesive.

[Carlman]

JFC (just for copper) has been sighted by me eyes down at ye old bunnings

i am sooo temted to make a nice copper rifle (and yes ill try to rifle it )

[Mitchza89]

Wowie....I've gotta keep my eyes on my own topic a hell of alot more I might buy myself a nice little torch but if I can get the JFC, I'll definately use that

Carlman, how much did the JFC look to be?

Hey guys.....Can the JFC really be that much different from a high grade epoxy?