Letter Re: A Low Cost Source for Powerful Magnets

Several years ago I was looking for some hi power magnets for a project, and found them, inside microwave ovens. Not wanting to get the wife mad, I placed free want ads for junk microwave ovens and got more than I expected.  As a side benefit each oven netted a small bit of aluminum and some copper wire. 

Getting to the magnets was almost too easy.

DISCLAIMER:  Don’t hurt yourself.  Sharp metal may be encountered, and a bit of electrical knowledge would be helpful.  Do not attempt repair to broken ovens without proper training and equipment to check for leakage. You are ‘on your own’ with this project.  For information only.

First thing, make sure the oven has sat unplugged for several days, so as to allow any stray voltage/current to dissipate [more for piece of mind-just do it], then remove the power cord-I usually just cut it off.
Remove the glass tray if it is still on the inside, then the metal cover.  Looking behind where the controls are located you will find a [usually] square looking electrical ‘thing’-the magnetron, with some aluminum fins.  Disassemble this and you will usually find three or four magnets inside. (No, there are no residual microwaves to harm you!) [JWR Adds: According to SurvivalBlog reader “NoName”: Magnetrons contain Beryllium Oxide ceramics. If this ceramic is crushed or begins to break the resulting powder is a hazardous carcinogen.]

CAUTION:  The magnets are powerful and will pinch fingers and other body parts if caught between a magnet and metal or another magnet.  You have been warned!

My originally-planned project bombed, and I still have numerous magnets around, holding papers, retrieving dropped items, etc. I always keep a few magnets inside a heavy plastic bag near my drill press to catch the dross.  The plastic bag makes it easy to separate the magnetic field from the dross, allowing the dross to fall into a collection can. [dross=drill shavings]

Happy hunting.  Oh, and the case, and rest of the microwave? Recycle it if possible. Otherwise just give it to the trash service. That is where it was headed in the first place. Regards, – Greg L.