Quote Originally Posted by Tim K View Post
So, I'm interested in ideas for the liner material. Plywood might be a decent choice since it has less glue than MDF, but I'd like something with no glue. I'll try drywall if I can't come up with something smarter, but all the dust and ragged edges make it unappealing.
I was kind of surprised that you used particle board and MDF for this as I would have assumed both would have outgassing problems at the high oven temperatures. Have you thought about building with sectioned heavy corrugated cardboard with standard styrofoam sandwiched between inner and outer cardboard?

Try mylar instead of aluminum foil for the reflectors. I believe gold-colored mylar is better than silver-colored for reflecting IR -- have to check some astronomy books but I seem to remember something about using gold-backed mirrors for IR telescopes because of the reflectance.