***
Some foamcore consists of thin sheets of styrene sandwiching a layer of dense
foam. That MIGHT be fine with a hot wire cutter, but I'd assume that the
styrene would melt along the edge. Instead of a square cut you'd end up with a
round cut.
***
My limited understanding of how the hot cutter works is that it's actually
bursting the bubbles that make up the styro 'foam', with the melted plastic
shrinking back from the wire, via surface tension(?). Done right, the wire
stays relatively clean. However, with solid styrene, even thin pieces, I'd
think it'd goop up pretty ugly...
Not to mention prolly break the wire. This has happened many times to me when
I've actually tried to push the wire through the foam instead of letting the
plastic part on it's own.
Slow cutting, with a slow sawing motion to keep a hot section of wire in
almost contact is de riguer, but most folks that work with it already know
that, so forgive the blithering.
By the way, when foamcore was mentioned in this context, I figured that the
card was stripped from the thin foam, in which case I'd think, but not
guarantee, that the wire would work fine.
Further by the way, I've seen 'styrofoam' stamped on the blue stuff, so,
either the term has gone the way of the zipper, or it's TM for more than the
hard, craft stuff.
The_Beast
-Douglas J. Evans, curmudgeon
One World, one Web, one Program - Microsoft promotional ad
Ein Volk, ein Reich, ein Fuhrer - Adolf Hitler
> Further by the way, I've seen 'styrofoam' stamped on the blue stuff,
Styrofoam started out as a product trademark, I think, for polystyrene foam
products. The best known is the
"compressed-bead" style *expanded* polystyrene; this is
what most people (in the US, at least) mean when they refer to "styrofoam". In
the building trade, *extruded* polystyrene is commonly used, because it
doesn't break down into individual beads when exposed to environmental
effects. (You *don't* want your basement insulation/seal
to break down! Expanded PS, on the other hand, is *slightly* more
environmentally friendly than expanded PS; that's why most styrofoam cups and
nearly all styrofoam packing material is expanded PS.)
If you're not sure of the difference, think of styrofoam cups. The ones with a
seam are *extruded* PS (extruded as sheets, and cut and glued just like paper
cups). The ones without a seam are *expanded* PS (expanded
into slightly-compressed beads in a mold).
I like to use expanded PS (salvaged from equipment
packaging) for naturalistic (i.e., non-stepped) hills
(for DSII), but extruded PS is much better for terrain
panels/bases because it is stiffer and less likely to
break. Both can be cut with a hot-wire cutter as long
as they don't have a paper sheath.
Foam-core from the hobby store is extruded PS with
a paper (usually) or plastic (vinyl, polyethylene, or
polystyrene) sheath on both sides. The paper-covered
foam-core can't be cut with a hot-wire cutter. The
plastic-covered foam-cores can be cut with a hot-wire
cutter, but it's a slow, messy process; you'd have to
stop every 10-15 seconds to clean the wire. Imagine
cutting a plastic (polystyrene) car model with a
hot-wire cutter, and you'll get the idea.
In general, as someone else pointed out, you need
to cut foam-core with a sharp knife, in two or
three passes.
- Sam