bulkhead orientation?

[spsick]

just setting up my new 120, doing the fun part( nothing like inadvertantly getting high off solvents!) wonder the proper orientation for the rubber grommet, do I want the little ridges on the glass, or the bulkhead? also, do I want to goo them up w/ some plumbers grease?

[MNGold15]

I put the smooth part on the glass and have not had a problem. I didn't use any plumbers grease. I have not had any problems for the 3 years it was set up.