How To Make A Hot Knife

Step 1: Why Make A Hot Knife?

Cutting plastic for your projects can be a real pain. I wanted to come up with a hot knife. I'll show you how to do that in just a bit. But I thought it'd be fun to show you a do-it-yourself idea like this evolves.

Step 2: Trial & Error

I started out trying to adapt an X-Acto knife head to a hot-glue gun. It looked great, but as you can see, it just didn't work. I tried the same thing with a soldering iron and wound up ruining the heating element in the process. Not having learned my lesson, I tried a larger iron. It worked great, until the heat degraded the aluminum head.

Step 3: Solution

And then the answer hit me. I hate it when that happens. Anyway, I was about the replace a soldering tip, when I happened to glance at a hammer. And there it was. Just pound the old head flat. It worked like a charm.

The cool thing about using a hot knife is that you can do a lot of things easier and faster than with a regular X-Acto knife or razor blade, and you have a lot more control. Need to fit a part into a project box? No problem. Trim off a thick tube? Once I got started, I couldn't stop myself.

So, if you've got a soldering iron, all you need to do is buy a new tip and flatten it. The cost? About $2. And you can switch back and forth between the cutting tip and your regular tip when you need to solder. Have fun, and thanks for watching.