A very inexpensive option for you would be disassembling a hard drive from an old unused computer. There are some very strong rare earth magnets inside of hard drives, and if you have an old one laying around collecting dust, you can have a free magnet, some even have 2. Of course it would only detect ferrous metals, but then again, most (not all) nonferrous metals are soft enough that a woodworking saw blade won't get harmed. The reason for using a strong magnet like a rare earth magnet, is because it can become attracted to metal buried in the wood that you can't see, just like a metal detector.
"The world is a dangerous place to live, not because of the people who are evil, but because of the people who don't do anything about it." - A. Einstein.
Last edited by Pagan Wizard; 03-18-2020 at 08:42 PM.