This is a tool that I've been missing for far too long. With all the styrofoam I have been hoarding for years it was time to make a hot knife, so I could start carving up patterns, prototypes and molds for lost foam casting. As it turned out I had everything I needed on hand.
- Some random brackets, nuts & bolts
- An old electric heater
- An old 12V 850mA transformer
I started with a 12Vdc 850mA transformer wired to each terminal, but burnt up three before I found a 9Vdc 750 mA transformer that worked more consistently. Even with the 9 volt power adapter the transformer gets too hot to hold after about 45 seconds of use. I decided to use my adjustable power supply, which proved to be the superior choice for extended use of the hot knife.