How to seal poly pipe?

[JKK]

What is the best adhesive for sealing 19mm poly pipe (HDPE) and fittings made from polypropylene.

[MitchellMc]

Welcome to the Bunnings Workshop community @JKK. It's terrific to have you join us, and many thanks for your question about pipe fittings.

Adhering HDPE pipe to anything, including polypropylene fittings, is notoriously difficult because both plastics are highly non-porous and chemically resistant. Unlike PVC, which can be joined with solvent cement, poly pipe is normally connected using barbed fittings that the pipe pushes over, then secured with a compression clamp or hose clamp to make a reliable, watertight connection.

I'm not aware of any common DIY adhesives that will reliably bond HDPE to polypropylene for plumbing purposes. For a strong, leak-free connection in a DIY setting, sticking with barb-and-clamp or compression and threaded fittings is by far the safest and most effective method.

Please let me know if you have any questions.

Mitchell
 

[JKK]

Thanks, I thought this may be the case. Just setting up some retic in my shade house feeding off mains pressure and want to be able to leave home for a couple of weeks and not return to burst connection. Thanks again

[AlanM52]

Hi @JKK,

With regard to @MitchellMc's barb-and-clamp suggestion and possible water leaks.

  

I always use good quality clamps and a correctly fitting nut driver.

That is my Garden Sentry - motion activated impact sprinkler that only needs low water pressure and I was still getting water leaks.

I now also insert a cable tie which helps to seal that gap.

Cheers