How to join two PVC pipes securely for water under pressure.

Treevan , 29 days ago

Bostik PVC Pipe Cement Green - Type P (Pressure)
Fast setting, high bond PVC pipe cement for use in Pressure applications.

For bonding with PVC-U Pipes and PVC-U Fittings
Suitable for pressure applications
Suitable for use in contact with drinking water

No additives of any kind shall be mixed with this solvent cement.
Priming fluids shall be used to prepare the jointing surface prior to the solvent cement application.

yoz OP , 29 days ago

Is primer really necessary? Cleaning the joint with a cloth will work ? I checked and I can o my get 250ml from bunnings which I don't think I am ever going to use. Seems like a waste for money ?

Treevan , 29 days ago

To put it in simple terms, the priming fluid sets up the PVC cement to do its job properly. The primer acts as a cleaner, removing grime as a PVC cleaner does, and it also softens the surface that it is applied on. PVC pipes are joined together through a change in their chemical composition.

(High) Pressure it likely matters, you want a strong bond. Stormwater/downpipes, probably not.

Not a plumber.

I just did a quick websearch for both these answers, try a deep dive on some Reno forums or similar, find a plumber or chemical expert as to why it's important.

Another one:

https://redlib.perennialte.ch/r/Plumbing/comments/camh2c/is_pvc_primer_reeeeeally_necessary_when_youre/

Quote:

You may as well just silicone the pipes together.

The primer softens the pipe to prep for the fusion process.

Without primer the glue is essentially just a gap filler.

That oatey cleaner you are talking about is for ABS pipe usually.

ABS doesnt require a primer but is often suggested to use that cleaner prior to application.

A link:

https://www.plumbingsupply.com/the-great-pvc-primer-debate.html

yoz OP , 29 days ago

Ah thanks bro. I'll buy both cement and primer tomorrow. Cheers

Treevan , 29 days ago

The graphs in that link are decent. It's a significant increase in bonding and if you are under pressure, definitely do it.

And I used to work with a plumber who used primer to set joints on fire to pull them apart again. Another use of primer that isn't on the label.

Taleya , 29 days ago

Yup.

I use glue-only for an above ground i want to break at some point and recoup parts. I use primer when i want it permanent. Glue only a strong twist can break it. Primer you're gonna have to get the saw.