Epoxy, Tapes, Glues: What Stops Leaks in Flex Pipe?

[PoolDoc]

I assume you are saying that it is a suction line, so a leak allows air IN, rather than allowing water OUT?

And, by "black plastic stuff that's a bit flexible" you mean smooth (NOT: corrugated) polyethylene pipe"

If so, the EASIEST permanent fix would probably be a "Fernco coupling":

1 1/4" Fernco coupling
1 1/2" Fernco coupling
2" Fernco coupling

A couple of points to keep in mind:

1. These couplings are ONLY for suction lines, or lines with no pressure.
2. You can cut a single split down the length, so you can get it on. If you do this, buy TWO, and use the extra stainless hose clamps over the MIDDLE of the coupling. Also, put some clear silicone (marine grade would be good) on the inside of the coupling, before you clamp it down.
3. If you can disconnect the pipe, and slide the coupling into place, that would be best. Use dishsoap and water if you need to, to make it easy to slide.

Just for reference, this type of Fernco coupling can be used for LIGHT pressure:

Fernco P3000-150 1-1/2" ProFlex Shielded Specialty Couplings

Finally, non-Fernco 'just-as-good' products are NOT 'just-as-good'!

[hotajax]

Thanks, Doc. Yes, it is that smooth black pipe, non-corrugated. Rough junk to work with. I rather hate it.

[PoolDoc]

Not my favorite, either.

But black poly stands up to UV, freezing, and chemicals better than almost any other piping.

Pressure? Not so much.

And then there's low-grade (= Chinese) stuff out there with uncertain properties.

PS: One thing to keep in mind: virtually nothing sticks to polyethylene. You can weld it, with the right equipment (if you know how to 'hold your mouth right') but otherwise anything you do to it must be mechanical.