This brings me to one of my unanswered questions in electrical life.

I've read some very good posts on arranging exterior conduit to drain, then drilling holes in the lower conduit bodies or boxes for drainage (or cutting a small section of the gasket out to drain). My only problem with these solutions is...what size hole will allow drainage (allowing for some corrosion or dirt that might plug the hole), but not allow insects into the system???

Dave