Hot wire foam cutter

Model Railroader General Discussion (Model Railroader)
1

I went to a hobby shop train show today and one of the demonstrations was a hot wire foam cutter that looked like a coping saw it worked great but the price $35.00 wow, I would probably use it once or twice a year, does anyone know of a way to modify a soldering gun to do the same thing. Beeline

2

Hey Vic, did you connect it to the AC or DC hookup on the transformer? …Jamie

3

Connect it to the variable DC side of the power pack. Advance the speed control to the point where the wire becomes hot enough to cut the foam but doesn’t trip the circuit breaker in the power pack. Remember you’re working with a “dead short” here. I would not use your good power pack for this project as its really hard on them. Use an old trainset power pack…Vic

4

Thanks Vic, this sounds like a nice inexpencive setup that cought my attention. I have about 6 of those old tyce power packs, lets put them to use. I take it the transformer won’t trip if i’m gentle with the amount of DC power, or will it eventually trip on me? …Jamie

5

HI James, It shouldn’t trip out unless it gets overloaded. Just experiment around with it and you’ll find the setting where it works best…Vic

6

Vic, this has actually got my a little excited. Can’t wait to try it. Thanks for the info…Jamie

7

I tried that once using a bent wire coat hanger as the tip for a Weller soldering gun…it gets too hot and just melts the foam but here’s what I ended up doing…
Cut a coping saw shape from a piece of 1/8 plywood. For the blade use a piece of thin nichrome wire…mine was salvaged from the element of an old electric heater. Make sure the nichrome wire is very tight between the bow of your “saw”…Silver solder a #20 or 22 feeder wire to each end of the blade (the nichrome wire).
I used an old Tyco trainset power pack to supply the current and it worked just fine. I gave it to a friend of mine years ago and he still uses it on occasions…CAUTION!!!..DO NOT BREATH THE FUMES THAT COME OFF THE EXPANDED FOAM WHEN IT IS CUT…THEY ARE TOXIC!!!..Vic

8

Thanks for the info Vic I will give that a try, Yes they warned us yesterday about the fumes being toxic, the demo was done outside, we were also told that if you power saw, wire brush, or use a rasp to form it wear a mask because the fine dust particles can get into your lungs and cause respiratory problems.
Beeline