Joining two faces together with flange

[flssfabrication]

I have two faces I am attempting to join together using flange. I feel like I remember seeing this done in a youtube video but cant remember how it was done. I can get the bottom piece to snap to the top piece, but that is not what I am looking for. I need both faces to be connected so they come together as one piece (so they can unfold into a flat pattern). I am looking for the two to be joined with one flange, having bends on the top piece and the bottom piece. Thanks in advance for help. Let me know if there is an easier way to go about this. I've tried a couple different methods. Attached is my current file. 

[jhackney1972 · Accepted solution]

There is only one way to join the top and bottom sheet metal faces and have them unfold.  I outlined it in a Screencast and also attached the model.  As I said, joining any other edges of each face will prevent it from unfolding but you can do it the same way.

[flssfabrication]

John, thank you. That is awesome and exactly what I was looking for. I almost had it. The last step I needed was combine. Thanks again. 

[lpieniaszek]

I second that motion!!! Exactly what I was looking for! Thank you!