Stangeness gluing PVC pipe

[themarkg]

I have done a fair bit of PVC sprinkler pipe repairs at my homes over the years but something strange happened today. I was doing a very simple thing - adding a second sprinkler head in a flower bed.

I purchased a brand new set of Oatley primer and glue, and new PVC pipe. In the final joint the 90 degree elbow came off after glueing like a repelling magnet. So I cleaned up the elbow and pipe with paper towl and sanded both very lightly with 600 grit sand paper. I tried again and the same thing happened. Then I cut off both pieces and glued for the 3rd time holding the joint together for 5 minutes. It was okay afterwards.

I wondered if there was water, but the pipe was absolutely dry.
I wandered if there was a pipe restriction and the elbow was coming off because of air pressure build-up in the pipe. Nope - I blew through the pipe easily.

This was strange. Never had anythings like this ever before. Maybe the new lue formulae is a bit different. Let me know if you know what the issue could be.

 

[Rickyman]

The instructions on the can of glue says hold the fitting on the pipe for 20-30 seconds to avoid push out.

 

[Helper Dave]

It happens. Could be the way that particular fitting and pipe are fitting together, or an excess of glue. Holding the joint together for 20-30 seconds is usually all you need to get them to stick.

 

[frodo]

You need to twist the fitting when you push it together
READ THE DIRECTIONS

 

[Matt30]

Frodo is right

Push on...twist into position. This will distribute the cement and help avoid push out. If you really glob it on you will get push out every time. All you need is a thin even coat

 

[Pat the Plumber CIL]

Purple primer seems to push more . I hold fittings 20 seconds with clear cleaner and glue , 30 seconds for purple primer . I think heavy duty glue will push more as well . Sometimes you cannot twist or spin the fitting . I was doing a new house a few years back . Got a phone call at the wrong time . Looked up and the fitting I just glued pushed apart . Last fitting in an octopus with all the fittings close together . Had to cut out 4 hours of work and re do it

 

[themarkg]

Thanks guys. Yes I did twist the fitting on each time and in the end I held for a while so all is soretd out now. The glue/primer must be reacting and PVC and giving off gas and pushing the fitting off - it wasn't gravity.