Roy, thanks but I can't get a 2x4 in there. The building itself is only about 2"x 2".
Rattler, your idea was what I was initially thinking about, but I decided that working my way up from a 1/8th bit hole to a 3/4" inch hole would be a lot of bits, and I have found on other projects, using wood, that when you do that, the sides (not the point) of each larger drill bit violently "grab" the sides of the smaller hole as it goes in, resulting in splintered wood and wood chatter around the edge of the newly drilled larger hole. So, that may be just too much stress on the plastic.
Dave, I think that your suggestion would work, but it would sure take some time and patience (and I am always short on both :-))
I guess I'll try Gary's suggestion of reversing a hole saw, and I'll let you know how it turns out. I'll tape up the plastic wall in front and back with heavy masking tape first. I think that it'll either work beautifully, or I'll press a bit too hard and break it.
I just remembered that years ago, I had to drill a large hole in a tile wall, and I bought a key hole bit for tile, which doesn't have teeth on the edge of the cylinder, but instead has an abrasive metal surface, for aggressively "sanding" the edges of the big hole out instead of cutting it out. Took a lot of time and created a lot of dust, and as I recall it was pretty expensive. I think it was about a full inch in diameter though, for use in plumbing.
Thanks for all of the suggestions.
Mannyrock
