Craft stores is a dead on recommendation -- I get mine at Hobby Lobby, but Michaels or JoAnne's fabrics should have something similar in their wood section.
I wonder if pressboard off of the old style clipboards would work? It's pretty sturdy and thin . . . might be a touch heavy . . .
*If* you can't find it there, before you order the plywood online, you might just want to order the laser cut ones from the FT store. They're not too pricey, and it supports the show. just a suggestion . . .
I have actually already ordered some control horns, a simple firewall, and t-shirt from the store. I was actually just curious if there was a more local solution rather than having to order online. We don't have a hobby lobby nearby either believe it or not.
I second the Michael's suggestion. I picked up some wood to make the firewalls out of from there. I made some control horns as well but the board that I got is a little thick so I had to split some of it off to make it work. They have an assortment of sizes and thicknesses, I just didn't know the thickness of the firewall and control horn pieces when I was there. I have a speed build kit and just traced the pieces out on my plywood but didnt think to measure the thickness
Ended up finding some at Michael's. I went with 1/32 thickness as I had heard Josh mention that 1/16 or 1/32 both work in one of the swapables videos. I was looking for 1/16 but the location that had the board was a mess and nothing was where it should have been. So after going through a few dozen pieces I just stuck with the 1/32. Once you glue and tape it into place it really isn't a problem that it's not the 1/16 though.
Now I just need to find an easier way to put holes in it. Ended up using a small drill bit to start a hole then an Xacto knife to finish it out.
I have purchased some of the FliteTest firewalls, and I believe the thickness is more like 1/8". Before ordering the firewalls, I went looking for the thinner plywood, but had a hard time finding it. When I finally did, it wasn't as thick as the stuff that came from FliteTest.
I was at Walmart today. In the craft section by the faberic, that had plywood silhouette cutouts of apples, dolls, and other stuff. I thought about buying some and making firewalls out of them. They were $0.79 each.
I have made a firewall with a table saw by cutting a thin sheet of oak with the grain, and cutting out the final shape on a scroll saw. It was very strong. I think I will just order some next time.
For control horns, I use gift cards, per Experimental Airlines.
Quick tip for anyone using Michaels for plywood. When you go into the store look for a copy for their flyer. There is almost always a coupon for 40 to 50% off one item that is not on sale already. Guess what they never put on sale, PLYWOOD.... This is also how a got a top notch airbrush for a decent price.....