Jay-T wrote:
I am pre-fitting some PVC fitting for a 3-inch sewer drain line
coming down from a first-floor toilet. Where the drain comes through
the basement ceiling from the toilet, there are two 45-degree 3-inch
fittings -- one is the toilet flange itself which is a 45-degree
fitting and the other is a 45-degree elbow. The place where they
come through the ceiling is hard to access.

What I would like to be able to do is put the two PVC fittings
together and then be able to easily rotate both so I can get the
correct angle I need to continue the run. The problem is that when I
put the two fittings together, they are next to impossible to rotate
while in place. I need the fittings to be able to rotate one inside
the other to get the correct line-up.
Has anyone ever tried lubricating PVC fittings first just to get the
fittings lined up correctly, then marking them for the correct
line-up, and then remove the lubricant and glue the fittings
together? Does anyone know what kind of lubricant might work for
this? So far, I have just tried dish soap, but that doesn't work --
the parts just stick together as usual and do not turn easily. Any
suggestions on what to use?

1. Lube it up with whatever you've got.
2. Place in position.
3. Mark pieces.
4. Remove and get as much chicken-fat, or whatever you used, off the parts.
5. Cement the parts together and install.

I believe since this is a DRAIN, and under no pressure, the chances of it
leaking are remote.