On 10/31/2010 9:14 PM, Tim Wescott wrote:
On 10/31/2010 08:57 PM, Steve B wrote:
I want to make a knife bar out of rare earth magnets to hold my kitchen
knives. If I hold the surface of the knives off just a tad, can I
avoid the
scratching that would be produced with the knives touching metal to
metal?
Or will there be enough magnetic attraction if I use thicker magnets
to suck
them up against a oak or plastic substrate that would be sufficient to
keep
them in place, and a few thousandths of airspace between?

Or lastly, to apply a thin plastic face onto the magnet so that it never
touches metal to metal?

If you get some 1/2 inch wide rare earth magnets, manage to glue them up
in a continuous bar without putting an eye out from flying shards, put a
thin piece of teflon tape over them and stick a knife on -- you'll be
grunting and looking for a nice bronze crowbar to get your knife un-stuck.



aaah, the usual way to do this is to use an equation - if it is hard,
look at the equation for attraction between cylindrical magnets on wikipedia