Cutting Styrofoam

[bigstick509]

My wife is a AP at a high school and graduation is just around the corner. Every year they have the graduation year on stage made of 4" thick Styrofoam numbers. I have been enlisted to cut the number "6" for the 2006 signage. My question is how is the best way to make these cuts in Styrofoam. My thinking is the bandsaw but maybe a hotwire knife or even a electric knife. Any suggestions would be greatly appreciated. These numbers are about 5' tall and 4" thick.

[final_t]

You can get a special "razor" bandsaw blade that has no teeth designed just for this (used mostly for cutting foam for furniture). You can make your own hot knife setup with a 12 guage copper wire and a battery charger, from what I've seen in various craft magazines from a few years ago. I don't think an electric knife or trypical bandsaw blade will do it since the teeth will yank the stryo balls out of the matrix.

[rickd]

My thinking is the bandsaw but maybe a hotwire knife or even a electric knife. Any suggestions would be greatly appreciated. These numbers are about 5' tall and 4" thick.

hi,

my wife's also a teacher so i occasionally get these jobs as well. i was curious about styrofoam as i usually end up with broken pieces so i did a google search using 'cutting styrofoam'. most of the sites seem to recommend either a 'hot knife' or a 'hot wire' to cut this.

here's a link to one of the search results:

http://www.ehow.com/how_13447_cut-styrofoam.html

i'd be inerested in what you ended up using and how it worked.

[Crash2510]

did a lot of work with styrofoam in school and nothing works better than a nice hot wire under tension

[gmack5]

did a lot of work with styrofoam in school and nothing works better than a nice hot wire under tension

I did a little research and found the link below that tells you how to build a "Hot wire" Bench cutter, similar to a Table Saw.
http://www.techlib.com/hobby/hotwire_foam_cutter.htm

I started the search using "nichrome" as the search Item. It appears, however, that Stainless Steel Wire works better. Read the article and draw your own conclusions. Copper Wire will not work very well as it elongates too much when heated.

[gerti]

Definitely look into the hot wire. Cutting it with any kind of regular knife or saw will created bunches of white statically charged residue clinging to everything. And it doesn't break down, so you will be finding it months and years later...

[bigstick509]

Thanks

Thanks everyone for your help, as usual this community is a great source of knowledge and ideas.

[Kensrock]

Cutting styrofoam

I've had some luck using dental floss tensioned in a frame. Use it like a saw. It's strong stuff. I've seen it used along with an abrsive for cut steel.
No heat involved. Safe around the teachers and kids.
Kensrock