I prefer to stain after assembly because you can cover up screw holes or other divits with putty then stain the whole piece of cage. If you use something like a cam connector for quick disconnects then stain each piece, then assemble.
As far as edges I could care less cause in my case the edge of the cage is never seen. The front is all that lines up away from the wall and all the sides touch hence no need to stain.
If you are building a single piece an want to stain the sides you can cover that ply egde with some trim then stain the trim. If you leave the edge exposed and stain it it will get really dark as it absorbs really well. I would say it will look like the stain does in the can.
So If I was you I would spend a couple cents and get some nice flat trim tack it on and stain the whole piece.
My 2 Cents
>>Hey, guys...
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>>I have couple of questions for those of you with experience building wood cages....with the stain, do you apply before you've assembled the cage, or after? Also, how to you handle the sides (edges) of the plywood? Will these exposed sides be unsightly after you've stained them, or does the stain even them out a bit? I'm using red oak for the cage I'm currently building...wanted to use birch, as recommended by someone here, but the birch that was in stock didn't seem to look very good. The Lowe's we have here isn't the best of stores....
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>>Thanks in advance for all your help!
>>Ray
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"I am become death, the destroyer of worlds" July 16, 1945 Robert Oppenheimer