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Custom diameter pipe

Posted: Fri Sep 28, 2007 5:12 pm
by Pilgrimman
This is a theory and has never been tested. (To my knowledge...) 8)

If one were to do some precise measurements, and cut a piece of pipe lengthwise (It would look lie a "C" if you pulled it open and looked inside it from the end, as opposed to an "O") and cut off a strip of pipe a certain width depending on your measurements, heated it so it bends, and solvent welded it back together, minus the strip you cut, you could have pipe with custom diameters! You could make tennis ball barrels that actually hold tennis balls with little friction, or paintball barrels with easy to find 3/4" SCH 40! You could still connect it to fittings by this also-untested mini-theory: Use PVC shavings mixed with primer/cement as a kind of mortar to fill the spaces. Or you could just use epoxy. Either way...

1: Has this been thought of/used? (Either theory)
2: If not is it feasible?
3: Would it be safe as a barrel? (I think it would, as it only holds pressure for milliseconds)

Posted: Fri Sep 28, 2007 5:14 pm
by Pete Zaria
It's been done before, lots of people have cut a thin strip lengthwise out of 2" pipe (and then sleeved that inside normal 2" pipe) to make a golfball barrel.

You kind of need to sleeve it inside a larger pipe for structural integrity. I wouldn't trust it unless it's sleeved.

Yes, it's feasible though.

Peace,
Pete Zaria.

Posted: Fri Sep 28, 2007 5:21 pm
by Pilgrimman
Well now that that's cleared up, I'm more interested in the solvent mortar idea! Thanks for the quick reply! 8)

Posted: Fri Sep 28, 2007 5:58 pm
by pyrogeek
What about if you solvent weld it, then slip some ring around it or something.

Posted: Fri Sep 28, 2007 6:05 pm
by jackssmirkingrevenge
How about casting the entire pipe out of epoxy, like I did for the breech of my preloaded cart prototype:

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With some reinforcement (wire mesh etc.) it would be strong enough to contain pressure.

Posted: Fri Sep 28, 2007 6:31 pm
by Pete Zaria
@Jack, I think you've found more uses for epoxy than all the rest of the members of this forum combined. I've only ever really used the stuff to seal leaks - here you're casting pipe, fittings, and other assorted parts out of the stuff.

I salute your ingenuity, sir.

Peace,
Pete Zaria.

Posted: Fri Sep 28, 2007 11:02 pm
by jackssmirkingrevenge
I thank my physics buddy at school who introduced me to the "proper" stuff (and got me several lb worth for my birthday lol) - the material has its disadvantages but with a bit of lateral thinking, it can be extremely versatile :)

Posted: Sat Sep 29, 2007 1:24 am
by frankrede
jackssmirkingrevenge wrote:I thank my physics buddy at school who introduced me to the "proper" stuff (and got me several lb worth for my birthday lol) - the material has its disadvantages but with a bit of lateral thinking, it can be extremely versatile :)
What disadvantages?

Posted: Sat Sep 29, 2007 2:26 am
by jackssmirkingrevenge
What disadvantages?
Say your mould isn't watertight and the epoxy leaks where it isn't supposed to, you're left with a solid mess in the morning. Also, unlike threaded fittings, to remove an epoxy component (unless you incorporate threaded parts) you pretty much have to destroy it.

Posted: Sat Sep 29, 2007 2:36 am
by frankrede
jackssmirkingrevenge wrote:
What disadvantages?
Say your mould isn't watertight and the epoxy leads where it isn't supposed to, you're left with a solid mess in the morning. Also, unlike threaded fittings, to remove an epoxy component (unless you incorporate threaded parts) you pretty much have to destroy it.
oh.
What do you to help keep molds watertight/what do you use for molds?

Posted: Sat Sep 29, 2007 3:08 am
by jackssmirkingrevenge
You have to use reasonably waterproof materials (meat tray foam, glossy cardboard, clear plastic etc.) and secure all the joints with glue, I normally use araldite for this application