I'm building a craftsman kit by FSM. Does anyone know of a website where I can buy a piece of foamboard to use as a base? The only sites I've found only sell it in packs of 5 or more.
Try store that "resale" building supplies. Habitat for Humanity is an example. If the plastic coated foam boards suggested aren't what you want would acoustic ceiling tiles work. They are stronger and shapeable but a lot thicker.
Arts and Crafts stores like AC Moore and Michaels have it. So does Staples. Give yourself some time to browse the Arts and Crafts places. They have lots of great stuff for layout-building. Paint, brushes, glue, balsa strips and such.
A word of caution on using foam board as a base for wood structures: the foam board will warp over time. I found this out the hard way after using it as a base for a scratch built engine house. The board warped and affected the structure... Was a real pain to extricate the structure from the board and repair it. My recommendation is to use .080 styrene as a base. It's very stable especially for larger structures. Below is a picture of the engine house when it was first done and mounted on the foam board. Unfortunately, I never took an after pic but a couple of years later the foam board warped and caused the floor to become detached from the walls in spots and also caused other structural problems... My original plan was to keep the structure on the foam board and mount it on my layout and then build scenery around it. ... What I ended up having to do was to mount it on a piece of .080 styrene sheet cut to the size of the floor. The actual floor is thin wood sheeting glued down to the styrene. You can see the sheeting I used for the flooring in the pic below:
to keep it from warping, you seal the paper on the foam core with minwax polyurethane, the regular one, not the water based one. brush it on and wipe off the excess with a rag or paper towel sealing the pores in the paper.
I'm assuming you've used that technique before successfully, but I have to ask whether there's a risk of the minwax soaking through the paper and attacking the foam?
the idea is not mine, it's a trick from RC foam plane builders world, but I have used it to make my dioramas. They coat their foamcore planes before painting, and as water proofing to prevent warping. Here's a link to a short demo and how-to. http://flitetest.com/articles/minwax-on-your-plane
Thanks for the explanation. Before that, based on prior experience, I would have been hesitant about using solvent based products around any kind of foam, but not so now.
I had never heard of paper covered foam before. The stuff in the craft stores has a plastic skin. But then I get my RC planes already built. It's a great technique to know though. Thanks.
Target and Office Depot cary foam core board. I use foam core board for dividers in the boxes i store and transport my freight cars. The box is a AVON box that the AVON lady gets her orders from the factory in. A AVON box will hold 40 fifty foot cars in layers of ten. The foam core board is what separeates the layers of freight cars