using a hot wire tool on foam insulation board. Do you need ventilation?

Model Railroader Layouts and layout building
1

…well; do you?

2

As Bill Clinton would say, “It depends on what you mean by ventilation.”

I generally do my hot-wire cutting in the garage, with the doors open. I don’t use a vent hood or fans. I hold my breath when I’m actually doing the cuts so I don’t breathe any of the vapors in directly, but I don’t take extreme precautions like wearing a respirator. Once in a while, I need to do some cutting on-layout, so I open the windows.

I’ve got the WS cutter, which is a U-shaped handle with the wire at the top. This limits me to about 6 inches of cut depth. So, I’ve worked out alternate techniques. I just take a big sharp knife and cut both sides of the foam as deep as I can, and then I can do a score-and-snap cut for long, straight cuts. Most of the on-layout stuff is small trimming, and I just use a utility knife.

I don’t think we ever got a good answer about the toxicity of this stuff under heat. I figure it can’t be too bad, because they use it in residential construction where the danger of fire is very real, and they don’t usually approve things that would be too toxic in situations like that. Does anyone really know?

3

As a rule of thumb, anything that produces fumes, vapors, or smoke should be done in an area where there is a good circulation of air or while wearing proper protective equipment. (Another rule of thumb is that if you can still smell it you don’t have enough ventilation or the proper protection.) I don’t think that the smoke is instaneously lethal, if that’s what you mean, but protectiong yourself is easy and worthwhile.

KL

4

Snowey,

Instantly lethal? No. But you should be careful about the fumes. Burning foam will release some small amounts of nasty chemicals so proper ventilation or doing as much of your work outside is possible is a wise move.

Tom

5

Woodland Scenics says it’s foam products are made to not produce toxic smoke when cut with a hot cutter. I built a lot of scenery with their stuff last winter (with all the windows closed) and had no problems. Other brands of foam can produce toxic fumes so you should be more careful when cutting them.