On Thu, 27 Jun 2013 14:29:10 -0700, Oren wrote:

Lesson learned. With fast set cement, insert the pipe into the
fitting, give it a quarter turn twist and hold for ~ 10-15 seconds.

It's amazing how the glue lubricates it so that the pipe fits on
perfectly, and, yet it wants to pop back out - so I agree with holding
it for a quarter minute or so.

Slow set cement; it is easy for the them to fail.

Yeah, but we need *that* stuff for fixing holes with just two
couplings and a center-pipe!

Or ... you use it in the four 90s method (which seems like overkill):
http://www.youtube.com/watch?v=WdYTg3oDKfU