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I am plumbing a pond and have some above-ground PVC pipe. I used the purple and blue glue to attach the pipes, but am concerned some pipes could still come loose. I plan to wrap the pipes with duct tape, but wonder if there is a better solution, as duct tape doesn't do well in situations involving lots of water. How can I reinforce the pipes to make sure they can't fall apart?

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    If you are submerging the pipes then don't even bother with duct tape. Even if you weren't submerging them, I probably wouldn't bother. If you are properly sealing the joints of the PVC with the manufacturer specified primer/cement for submerged applications, then you should be fine, at least for the rated lifetime of the adhesive. – TylerH May 10 at 18:50
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    IIRC, the blue glue only offers a benefit if you are working in the rain, which is what it's made for. If the pipes and fittings are dry, clear cement is just as good. Purple is normally primer, not glue. – Ecnerwal May 10 at 19:08
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    It's cement, not glue; it doesn't just stick the parts together. PVC cement dissolves and welds the material together. A properly welded joint is nearly as strong as the fittings themselves. What makes you think they'll fall apart? – isherwood May 10 at 19:45
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    I suggest applying cement to the female pipe first, then heating the connector with a torch or heat gun, and apply the cement on the inner face of the connector just before joining. Hold the joint on both sides for a minute or two, so the connection is stable and the connector will shrink and grab the female pipe firmly to make a tight fit sturdy joint. Wear gloves and heat the connector evenly, but not overheat that causes a burn mark to occur. Use a small brush to apply the cement generously. – r13 May 10 at 20:45
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    @R13 there is no need to heat a properly sized PVC connector. You simply apply cement to the inside of the bell end, to the outside of the pipe, push them together and give them 1/4 turn. Before you can heat PVC enough to significantly expand it, it loses rigidity and then burns, neither of which help in this application. – K H May 11 at 8:14
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Either you glued them correctly (I prefer "cleaner, then primer, then glue" for the most reliable connections) or you'll need to re-glue them after the joints fail.

Nothing you add to the outside will change that.

You do need to paint or otherwise cover them to prevent damage from the UV in sunlight, since you mention that they are above-ground.

Duct tape is a poor choice, it falls apart outside rather quickly.

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It won't fall apart. It just won't. PVC glue doesn't work like most glue. It's not a sticky substance that goes between two surfaces and holds them together. Instead, it chemically melts the pieces together, basically forming one piece. PVC is used all the time, in homes, ponds, pools, factories, basically everywhere where pipe is needed. You don't see them wrapping the connections with duct tape, do you? They are gluing it together just the same way as you. So don't worry about it, I promise it won't come apart any time soon.

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Many pond builders use schedule 80 PVC for ponds for the increased strength. Consider that. You can also build a pump box to strap the PVC to

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  • How does Schedule 80 improve joint strength over Schedule 40? – isherwood May 10 at 19:53
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    Schedule 80 has a thicker wall, thus more rigid and deflect less under load. But it's not the problem OP is facing though. – r13 May 10 at 20:27
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    I assume the OP is worried about the joints shifting or being bumped because they are above and below ground and near a pond that may have people around them. As others have pointed out the "glue" is really just a weld. – redlude97 May 10 at 20:33
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    @isherwood A properly welded join iin thick pipe will be stronger than the same weld in thinner pipe. pipes are solvent welded, not glued, together. – Jasen May 11 at 12:21
  • I'm aware of that and said as much above. That's not really the question, though. – isherwood May 11 at 12:43

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