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Clearance Epoxy

Posted: Wed Jun 06, 2007 11:33 pm
by judgment_arms
Hay all,
Do any of you know if this stuff will bond to PVC?
I’d like to know because the China-mart near me has it on clearance for 10 cents a pop!
Thanks.

Posted: Wed Jun 06, 2007 11:39 pm
by Matt221985
china mart? lol, is that a real store?

Posted: Wed Jun 06, 2007 11:44 pm
by homedepotpro
i would not put my well being on discount china-mart epoxy

Posted: Wed Jun 06, 2007 11:53 pm
by judgment_arms
I call wall-mart, china-mart because every thing there is from china.
Well, I already got five of them; maybe I’ll try it and see.

Posted: Thu Jun 07, 2007 11:53 am
by boilingleadbath
If?
I'm pretty certain it will.

On the other hand, it may only have a 1,000 psi bond strength - or something like that... so you may not want to use it to epoxy fittings together.
Not that that changes anything, because we don't advocate that use anyways.

Posted: Thu Jun 07, 2007 12:16 pm
by judgment_arms
Well I need something to plug the end of a piece of pipe from the inside. It woulcd not be under constant pressure, only for a short amount of time. Think of it as a breach block.
Would it work for that?

Posted: Thu Jun 07, 2007 12:50 pm
by boilingleadbath
we need dimensions of the scenario:
Diameter of the pipe
Length of the epoxy plug
Pressure

Posted: Thu Jun 07, 2007 12:58 pm
by judgment_arms
Okay then,
Pipe diameter = 1.5
Plug length = as much as necessary for safety.
Pressure = 120 max PSI

Pipe diameter = .75
Plug length = see previous, but no more than half an inch.
Pressure = 200 max PSI

Posted: Fri Jun 08, 2007 12:57 pm
by boilingleadbath
If we presume those are .75" and 1.5" nominal (.802" and 1.59" actual inside diameter)...

1.59<sup>2</sup>* pi/4 * 120<sub>psi</sub> = 240<sub>pounds</sub>
240<sub>pounds</sub> * 3<sub>safety factor</sub> / (1000<sub>psi</sub> * 1.59*pi) = .14"

.802<sup>2</sup>* pi/4 * 200<sub>psi</sub> = 101<sub>pounds</sub>
101<sub>pounds</sub> * 3<sub>safety factor</sub> / (1000<sub>psi</sub> * .802*pi) = .12"

A couple notes:
1) These are thin enough that their strength as a flat plate may be lower than their ability to stay glued in the pipe... increasing their thickness would not hurt.
2) Required glue contact area (the values I calculated) scales liniarly with pressure.
3) A higher safety margin - like 6 or 10 - wouldn't hurt.

Posted: Fri Jun 08, 2007 1:26 pm
by iknowmy3tables
that pipe is kinda big to be pluging with epoxy, you should use pvc parts, it you have a lathe try pluging that 1.5"pvc with part of a sanded 1" end cap and the 3/4"pvc with a .5" cpvc end cap