Select only interior faces within a tube

I have done some neon CGI renders in the past and plan on doing another one here soon. One thing I haven’t done in the past that I want to do on my next render is have the inside of the glass tubes be a different material - frosted/painted glass. I can easily select the interior faces and change the material on a simple shape, such as a cylinder, but with increased complexity it gets much more difficult to do manually. What method would you suggest I use to select all of the faces that will act as the interior of my neon tubes?

Try setting your selection criteria of the view-port, to only allow selection of visible faces, instead of selecting all the way through. Rotate your model and use either “C” or “B” to select your polygons, until satisfied, the Invert your selection. Should be good.

Select a ring of edges on each end, then ctrl-period to select the inner faces.

ctrl+period is individual origins pivot by default. Selecting edge loops on each end and select menu -> select loop inner-region should do it (ctrl+i to invert selection if necessary).

Thanks, JA12. My key config is highly edited. I looked at my input settings before I posted that, but apparently I suck at that too.

Yes, select loop inner-region is the key bit.