OK so I'm trying to get a drain from a sink in my workshop back to the shower room (all in the basement) - I've run 3/4 tubing back to the shower room, now to get it through the tile in that room (on the wall). I've tried using my 1" bi-metal hole saw pouring water on the wall while drilling. The guide hole might be done by next month... this is just not efficient. Anyone have a diamond hole saw similar size? (or better idea how I can do this?)