Good Morning John,
Okay, I did a search on the web and a guy with the same issue popped up and I followed what he had done, but with a few small exceptions. I started off using a cookie sheet, that didn't work 'cause it was too flimsy. Then I used a cast iron griddle, a much more solid surface flat surface. I placed the parts and griddle in the oven, cold. Set the oven to 250* and preheat. Let it warm up, Then turn off the oven when it's preheated (DONT LET IT SIT IN THE OVEN @ 250*) and let it cool completely, leaving it in the oven with the door closed. Don't remove it until its completely cool. This is going to stink, turn on your hood vent fan.
The key is slowly heating it up, and slowly cooling it. 250* wont melt anything, just softens it. This is why you dont move it from the oven. Just let it cool. LOTS OF PATIENTS! This takes time. NO weight of any kind is necessary. Once they're flat and cool, store them on a hard flat surface until your ready for them. Dont put them back in the box. Painting and weathering can be done at this time.
I used superglue to glue the panels together. I didn't sand the sides smooth, I should have.
You have the plans for the framing? If not, I got them still. All of the cross bracing has to be cut to length. So sanding the sides would be okay. Just need to be sure you get everything equal.
I added, lots of 45* bracing to my wood framing as shown above. Making it look more prototypical and structural. When you build the framing, use a small square or a speed square to get the proper angles. You will only have enough wood for the planned framing. I got a 1/4" x 2" x 3' piece of poplar and ripped that down to 1/4" square strips. This is what I used for the 45s and all the cross bracing. I used wood glue for the framing. Put wax paper under your framing so it doesnt stick to the framing plans. (old balsa wood plane building trick) Use lots of T-pins to hold the wood pieces in place until the glue dries.
I then sanded everything with a palm sander using 320 grit paper.
Good luck, ask any questions. I'm on here every morning, lurking.
Forgot...One last thing, use something that's long enough and straight to use for the "roundhouse floor". Like a metal yard stick. Butt all of the columns of the framing to this. This ensures the framing will sit on the floor evenly. Ask me how I know....Found out the hard way.
