Weaknesses of Epoxy

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Weaknesses of Epoxy

Post by MarsGlorious » Tue Aug 05, 2008 9:05 am

Well, I cut open the valve of my CPS 1000 to fix a leaky pull valve. The leaking was kind of solved. However, it created a new problem. The epoxy wouldn't hold the valve and the valve would leak. I reinforced the valve to a point where I thought it would hold well. However, during battle, the valve started leaking heavily. It was busted again.

It was due to a weakness in the epoxy that I hadn't considered. It was pretty much the point where the epoxy sticked to the valve. When the PC/Bladder was at high pressure, it would gradually push the two halves of the valve apart. As the bond of the epoxy to the plastic is the weakest part of the epoxy fix, it would break. This would allow the halves to move further and ruin the epoxy fix.

When I discovered this, I was relieved because the solution was right in front of me. I told you in the leaky pull valve thread that I reinforced it with wire on one side. Well, the side with the wire stayed perfectly intact. I came to the conclusion that if you reinforce the epoxy with wire (on both sides) and spread out epoxy the problem shouldn't occur. The wire prevents the valve halves from moving apart.
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Re: Weaknesses of Epoxy

Post by Silence » Tue Aug 05, 2008 5:28 pm

Good solution. That's a bit like reinforcing concrete with steel beams - concrete can take compression but not tensions, and with steel rods it's the other way around, for the most part.

Also, remember to sand the areas with fine-grain sandpaper if you can. You may also want to glue a strip of plastic or metal over the broken area like in the snapped trigger repair. It's the same concept - use metal to take tension. :cool:

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Re: Weaknesses of Epoxy

Post by SSCBen » Fri Aug 08, 2008 1:00 am

Nice idea. Sometimes you need something to take the tension as SilentGuy said, and epoxy isn't always the best thing to do that. Metal strips, wire, whatever you have could work. Perhaps we should suggest this more often.

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Re: Weaknesses of Epoxy

Post by Drenchenator » Fri Aug 08, 2008 1:04 am

That sounds like a great solution! Do you have a picture of your repaired valve? I follow what you did, but I'm having trouble picturing it vividly. I kept think of reinforced concrete like SilentGuy; perhaps I should be thinking of that though. Still, a picture would be helpful for anyone else with a similar problem.

Great job on the repair!
The Drenchenator, also known as Lt. Col. Drench.