At least once a week I look under a kitchen sink and just have to shake my head. I don’t understand how people can turn such a simple project into a glued, taped, caulked, flex piped leaky mess!!
It really is this simple:
If you have a disposal, put it on the right side and change one piece of pipe for a disposal adapter tube.
Everything you need comes in a couple of small kits. One to connect two sinks, one trap kit, and a trap adapter that will glue on the wall pipe.
This is all easy to use plastic pipe. Pieces slide into each other so measuring is not that critical.
Compression collars with plastic bushings make a tight seal easily without glue, teflon tape, teflon paste, silicone, or any other goo!! You put a ring of plumbers putty on the top side of the sink and drop your drain flange in.
Per code, all pipe shall be smooth wall with no restrictions or reduction in size.
This means no flex pipe. Definitely do not use flex pipe horizontal, it will clog.
Wright Inspections LLC