BRACE YOURSELVES: I found an inexpensive yet amazing foamcutting knife at Fred Meyer the other day. So far, I have only used it to cut foam for blueswords, but man, it is cheap and sturdy.
I’d been using packing knives, pocket knives, box cutters, etc. for a while, but its difficult to get them to make perfectly clean cuts. They squish the foam and cause uneven edges. Even with making guide cuts first, instead of just trying to cut all at once, the cuts often end up sloppy. I had heard that steak knives worked well for cutting foam, but hadn’t tried yet. I found a pack of 2 cheap steak knives at fred meyers and grabbed them to test. Unfortunately they were only beveled on one side, so the tendency of the blade cutting the foam was to slide off the side and create a bevel. They still worked fairly well but I had to be very careful and make many cuts, switching directions to keep the cut flat.
The next day I went to Fred Meyer again for a supplies run, and ended up buying probably the last knife I will ever need for foamsmithing. I had seen it the previous time, but thought that the 5.5″ blade would be unwieldy, fooling me into getting the aforementioned steak knives. It was also cheap (about $7 with tax) so I grabbed it. The serrations are much smaller and sharper than the steak knives, the blade is thinner, stiff, and beveled on both sides. This knife is WIN. It was very easy to make clean cuts on 4# gym mat foam.
In short, this knife is awesome, and it cuts foam like a lightsaber.