"Lew Hodgett" wrote in message
eb.com...


Rough up back side of magnet with a coarse grinding wheel.

Which brings up the point that some rare-earth magnets are made of materials
(cobalt, neodymium) considered fairly toxic. If memory serves the REM I got
from Lee Valley had instructions telling me to wash my hands after handling
the magnets. So perhaps the grinding wheel thing should be reconsidered.
Lee Valley also says their steel magnet mounting cups increase the
effectiveness of their magnets by four times.