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Posted: Tue Dec 27, 2011 2:06 am
by subterranean
i've used 1/4" brakeline with steel bbs and it was never accurate. i was hoping there is a place to buy brass pipe in a 4.5mm id. :?

Posted: Tue Dec 27, 2011 6:51 am
by wyz2285
well have you tried to buy a .144 barrel? I searched in ebay and didn´t found 4.5 ID tubes and personally I have never found one anywhere either...

Posted: Tue Dec 27, 2011 10:35 am
by Gippeto
wyz2285 wrote:Hi I´m making a new pcp rifle, and I´m planing using a stainless steel tube as chamber, 0.75mm wall. Is it safe to use 1000 psi with it?
Not enough information.

What "kind" of stainless? ie 304, 316, 440, etc. You need to be able to determine the yield strength of the material...can't find that if you don't know what it is.

What's the outer diameter?

How are you going to secure the ends?

Posted: Tue Dec 27, 2011 4:14 pm
by Lockednloaded
Would it be ok to tap a 1/8" thread through double layered 3/4" copper (type M tubing JFC'd into a 3/4" cap) if I plan to use up to 500 psi?

Posted: Tue Dec 27, 2011 4:19 pm
by mark.f
Uh, JFC'd?

The total wall thickness of those two parts would be just about 1/16"... really not enough thread engagement IMO for a course 1/8" NPT thread.

Posted: Tue Dec 27, 2011 4:28 pm
by Gun Freak
JFC= just for copper, a chemical bonding thing for copper. I wouldn't tap that small depth. That's only maybe 2 threads to engage.

Posted: Tue Dec 27, 2011 4:29 pm
by Lockednloaded
JustForCopper glue, it supposed to hold like 600 psi. What if I reinforce it with some epoxy?

Posted: Tue Dec 27, 2011 4:31 pm
by Gun Freak
Surely there's another option? I wouldn't trust the epoxy reinforcement either.

Posted: Tue Dec 27, 2011 4:31 pm
by mark.f
I don't know if you can get to the inside, but I think it you threaded the fitting through and added a sliver of 1/8" coupling and some epoxy on the other side it would be alright.

Posted: Tue Dec 27, 2011 4:36 pm
by Lockednloaded
I guess I could put it in the end of the cap so it'd be easier to reinforce

Posted: Tue Dec 27, 2011 5:14 pm
by Gippeto
You can get reducer bushings that have thread in them....they're designed to sweat into copper fittings to attach such things as snifter (schrader) valves...look in the heating section where they have boiler system parts.

Posted: Wed Dec 28, 2011 12:44 am
by jackssmirkingrevenge
subterranean wrote:i've used 1/4" brakeline with steel bbs and it was never accurate. i was hoping there is a place to buy brass pipe in a 4.5mm id. :?
The problem is that steel BBs are 4.4mm ID...

Posted: Wed Dec 28, 2011 1:26 am
by sl33k
Hey, I was wondering if there is any useful tutorials on the application of liquid epoxy. I have used two part modeling epoxy before but never liquid epoxy and was wondering if there are any particular brands or types I should be leaning towards purchasing.

Any help is really appreciated :)

Posted: Wed Dec 28, 2011 2:22 am
by jackssmirkingrevenge
sl33k wrote:Hey, I was wondering if there is any useful tutorials on the application of liquid epoxy.
look no further:

http://www.spudfiles.com/forums/epoxy-c ... t8916.html

http://www.spudfiles.com/forums/making- ... t8919.html

Posted: Wed Dec 28, 2011 5:23 am
by wyz2285
What "kind" of stainless? ie 304, 316, 440, etc. You need to be able to determine the yield strength of the material...can't find that if you don't know what it is.
I don´t know :? just normal stainless steel tubes used for water...
OD wound be 22mm