Time to update this thread. Things have been moving along slowly, but moving.
Here is a shot of the stage skinned with two layers of 3/4" OSB with a layer of roofing felt in the middle. Sorry about the mess, I struggle with cleaning as I build.
Here I started to build my columns. Mine are primarily decorative. My surround speakers will be mounted on the outside of the column like a traditional big box theater. The main reason I did this was my back row will be 5 seats across I didn't have the room to make the columns any deeper than 4.5" to mount my surrounds inside them, way to big. I made my columns out of 3/4" MDF Some with mitered edges and some without. Here is the process I used to finish:
1. Sand down to 220 with orbital sander until the edges of MDF are very smooth.
2. Skimmed with 1 or 2 coats of MH Ready Patch to fill in the joints then sanded to 220 each time.
3. Rounded corners, taking off sharp edge of corner, with 220 sanding sponge
4. Primed all surfaces of the MDF with Zinsser BIN Primer
5. Sanded primer smooth with 220 sanding sponge
In the pic below the column on the right is mitered and the column on the isn't. The non-mitered columns were a lot more difficult to finish since the edge of the MDF was rough. This was the way Cinemar did his columns. The reason I did this was that my track saw was kinda hard to do 45 degree angles on such a long cut and the cuts weren't coming out perfect.
Here I painted the can light bezels flat black. I used a rattle can high temp black used for grills. This paint comes out dark grey and not very black. Since the cans are halogen I didn't want to used low temp paint. In other threads I read that some people have used low temp paint without issue.
Below are some shots of my wall cleats. I started with building a frame then I just used used spare 2x10s and 2x12's I had left over.
I filled the columns with insulation, because that's what we do, empty space, fill with insulation
Column installed with crown molding.
In total, I have 7 columns. I'll get some better shots as I get closer to the end so you can see the layout.
At this point I changed gears and worked on the LED lighting tray. I installed vertical 3/4" plywood to the lighting channel to attach trim and then the crown molding. Biggest mistake of this build was that I mounted the HVAC reg on the ceiling and not in the soffit. In beginning I didn't think I was going to do a lighting tray. Looks bad with the LED light on, all well... moving on...
This pic illustrates the way I did my LED channel to hide the wires and power packs.
I copied Cinemar's lighting channel trim arrangement.
I couldn't help but to mount the LEDS before the crown.
Here is a shot of the first piece of the 5.25" crown molding, I likey!!!
Next I need to mount the crown molding to the rest of the columns. Then it's on to the custom wainscoting and all the trim that involves.