I’ve had a number of questions come in regarding a post I had a couple of weeks ago. I had mentioned that gluing together rigid pink insulation was an inexpensive way of making many prototypes without using a lot of wood. The proper name for the material is Foamular 250. It’s extruded polystyrene insulation and it’s made by Owens Corning. It has an R-Value of 10.
You can find the material in the home centers, but I’ve never had to buy it. When I worked at the Rhode Island School of Design, the students used to buy it for their projects, use a only small portion, and then throw away the rest. The students at RISD do that with a lot of really good art supplies, so the employees look forward to the treasures that are dumped at the end of the school year.
You can also find it easily in the dumpsters of new construction sites. Usually, the contractor won’t mind if you snatch it up because you will be saving them the hassle and expense of having it carted to the dump. Just don’t make a mess. Sunday is a good day to look without being disturbed.
The prototype foot that I cut today is from a small sheet that is 2″ thick. I believe it originally came from a sheet that was 4’x8′. I ripped a piece to 4″ on the table saw and doubled it up with some spray adhesive. Within a couple of minutes, I was carving away at the band saw.
The nice qualities about the material, aside from the cost, is that your band saw will move through it like butter, and the dust won’t stick to the machine with static electricity like some other foams. And because it is so easy to work with, you can try out a bunch of different designs with out breaking the bank. Pink isn’t my favorite color, but you can spray paint it easily enough if it bothers you.