PVC pipe gluing question

[mlincoln]

Put in a new p-trap and pipe section under the sink.  Noticed that I had a leak on a glued connection, which was rather surprising.  I watched some videos on YouTube to try to figure out what I was doing wrong, and I realized that the guys on YouTube were using A LOT more glue than I was.  Purple primer was the same, but I was only putting a bit of glue on both the male and female, wiping a lot off on the inside of the glue can.  So I redid things and used a lot of glue.  No leaks.

My son was helping me and we went out in the garage with some left over fittings and pipe and played around with it.  Using a lot of glue we got water-tight connections, but we noticed a fair amount of glue was sort of spooging out into the pipe or connection.  When we were all done and had held it for 30 seconds, we could see the dried glue down inside the pipe.  

We talked it over and said that these were all for drains, so a bit of extra glue inside the pipe probably wasn't a big deal.  Thoughts on this?  The technique we settled on was bringing the glue dipper out of the jar, letting it hand for about two seconds and then wiping off the little tail, and then smearing that on the pipe and fitting.  Is the general consensus that more glue is better than less?

[Scouter]

I usually dry-fit the pipes, mark the top of where they meet, then apply the primer and glue to that level, all around. Never had a leak,

[farmerj111]

I've done a lot of PVC and I learned not to skimp on the glue or primer.  Never had an issue of squeeze out affecting flow.

[crokett™]

It doesn't take much glue. Even distribution is the key. I dry fit and get things aligned, then mark the pieces with a sharpie, then pull them apart, apply glue and rejoin while twisting to spread the glue. Finally align to the alignment marks. You have a few seconds to work.

[Stwood_]

I've done a lot of PVC and I learned not to skimp on the glue or primer.  Never had an issue of squeeze out affecting flow.

+1

[Robert Adams]

Just slop it on there and push together. Don't be a perfectionist and make the layer even and try to make it look perfect. Gluing PVC is like framing, it's called rough plumbing and rough framing for a reason.

     PVC joints are tapered and if you don't have enough glue on you can't get the pipe to slide far enough into the joint. That taper is why the pipe will push out if you don't hold it.

[fixtureman]

I always give it a small twist when putting them together

[blackhat]

The two most common issues are leaving burrs on the pipe end and puddles of primer in the fitting socket. Deburr the pipe end until it has a small bevel on the end. A file or sand cloth works fine. Don’t gob primer in the socket and let a puddle form. You can’t spread glue on top of liquid primer and it will weaken the glue bond. Test the primers effectiveness. You should be able to feel the pipe surface softened if you try and scratch it with a fingernail. Primer goes bad and occasionally we find pipe that will not soften with primer. You will not get a good joint in those circumstances. A slight twist as you assemble is recommended and then hold for a minute to prevent creep out.