Aluminium Tube Pressure Rated?

Mitchza89 · Sun Apr 27, 2008 9:11 pm

G'day guys,

I saw some nice aluminium tube down at my hardware. 8 bucks for a meter of 25mm (WAY CHEAPER THEN COPPER!)

Is this stuff safe to use on a cannon? I've got no clue on what pressure it could be taken too...

Cheers,

Mitch.

hi · Sun Apr 27, 2008 9:25 pm

it depends on if its for pressure or if it is just electrical conduit pipe. there are many different grades of aluminum, so with the information that you have given us, its very hard to say weather or not its safe.

another problem is that because aluminum isnt used for plumbing, finding fittings will be nearly impossible.

Mitchza89 · Sun Apr 27, 2008 9:27 pm

I thought fittings would be very hard to get aswell. I was stoked to find that a 25mm fitting, fitted the 25mm pipe very, very well. That's what has got me excited

. On Ebay, I can get a meter of 25mm brass tube for 10 bucks with 5 bucks postage. Very cheap if you ask me

.

Cheers for the help mate.

socoj2 · Mon Apr 28, 2008 7:49 am

Tube is generally not pressure rated, that is not to say you couldnt use it, its just not rated and you can get some really thin wall Tube

Aluminum Pipe you will find pressure ratings for.

SNDM · Mon Apr 28, 2008 12:02 pm

Isnt welding Aluminium rather hard.
Doesnt it need special gear?

socoj2 · Mon Apr 28, 2008 3:53 pm

SNDM wrote:Isnt welding Aluminium rather hard.
Doesnt it need special gear?

Yes. it is a Giant PITA

goathunter · Mon Apr 28, 2008 4:10 pm

Isnt welding Aluminium rather hard.
Doesnt it need special gear?

Yep one of these:http://en.wikipedia.org/wiki/Gas_tungst ... _magnesium

Or you can do it old school:http://tech.flygsw.org/weld_aluminum.htm

The main issue is prep and not getting it too hot. If it goes too hot it runs right off and won't stick.

Like Socoj2 said: A real pain in the rear

JDP12 · Mon Apr 28, 2008 4:13 pm

indeed it is, IMO i'd go old school...simpler and somewhat cheaper.. most people have a propane torch lying around.

Mitchza89 · Mon Apr 28, 2008 7:20 pm

The stuff I found has walls that are a couple of mm's thick. I was planning on using epoxy to bond everything together. My main worry is if the epoxy will properly bond to it...

Mitchza89 · Mon Apr 28, 2008 8:37 pm

Sorry to bump up the thread guys, but I reckon it's entirely possible to make a rather high pressure gun using aluminium tube. I've got some 15mm (not nominal bore) tube that has some pretty thick walls. I can't bend it with my hands like I can with even the hard drawn copper pipe up to 20mm (not NB). If it fails, It would just tear, not explode. I reckon it could easily hold 200+ psi.

I'll get myself some decent epoxy and do some pressure tests on this stuff and see how I go.

I'll keep ya posted.

goathunter · Mon Apr 28, 2008 10:15 pm

Well mitchza,

I've used JB Weld to good effect on aluminum. I'm not sure the availability in AUS. Epoxy unless it's made for non porous metals won't do much good.

Mitchza89 · Mon Apr 28, 2008 10:20 pm

Yeah that was what I thought. I'll get my hands on some automotive epoxy putty. Apparently it's pretty tough stuff.

elitesniper · Mon Apr 28, 2008 10:32 pm

Yeah use epoxy putty

I now prefer that over regular epoxy putty, its much cleaner and holds loads of pressure( sorry jsr

)

bigbob12345 · Mon Apr 28, 2008 10:38 pm

I wouldnt take the aluminum pipe over 100psi but if you want to take it higher then I cant stop you. Just if it starts to buldge, you might want to realease the pressure.
Im still a fan of the good ol' liquid epoxy, I just find it more useful

Mitchza89 · Mon Apr 28, 2008 10:42 pm

What sort of epoxy are you talking about Elitesniper? The liquid epoxy or putty?