As I said previously my beam is made like this, with the bottom piece having tongues on each edge which sit in grooves in the side pieces. So the next thing I did was put grooves in all the side pieces and made rabbets on the bottom pieces, which left the tongues to go into the grooves.
The next job was to stain all the pieces:
I glued just one side piece to the bottom piece, this would allow me (actually my husband) to wire up the lights easier than trying to do it with a completed beam.
Here you can see that the beam is just an L shape for now with the front (side piece) off. I screwed the back side piece into the 2×2s. This way the wiring is inside and cut to the proper lengths for each of the four pot lights.
The pot lights were then wired in place and could be checked to see that they worked properly before sealing up the beam:
The front side piece was then screwed in to the 2×2s at the top (after this photo was taken I painted the screws a brown that left them pretty much invisible):
and also glued and clamped along the bottom:
Here’s the finished dovetail, which I actually put more dark stain around so that the shape of the dovetail would show up better:
Hope this gives you some ideas for your own ceiling beam.
-- ~Julie~ followyourheartwoodworking.blogspot.ca