On Wed, 20 May 2015 15:07:01 -0400, Dan Espen
wrote:

writes:

I've always wondered if it's possible to use a very powerful magnet to
remove nails from lumber? I'm sure that the magnet would have to be a
really strong electro-magnet, such as the ones they use to lift cars at
auto junkyards.

However, if this is possible, it may not be something that should be
exposed to the public, because it could become a weapon. In other words,
someone drives up to your home, activates the magnet, which removes all
the nails as well as steel plumbing, metal electrical boxes, your
appliances, and so on. This, in a matter of seconds, your home would be
nothing but a pile of lumber, with all your (non-iron) furnishings
buried in the pile, and all your iron metalic furnishings as well as all
the nails from your home, leaving the scene by some crook.....

And, dont forget, your belt buckle is metal. Say goodbye to your
pants!!!

Too much X-Men.

A force like magnetism decreases as the square of the distance.

Even a junk yard magnet would have trouble at an inch (guessing).
2 inches, 4 times worse.

A powerful magnet, with only "pin point" accuracy would be real useful
for nail removal. In other words, the magnet would be held right over
the nail head. I'm not sure just how much force would be needed though.
But considering I can remove a nail with a pry bar, I dont think I'm
applying more than a few hundred pounds of pressure. Yet, if the nail
head is even slightly below the surface of the wood, a lot more power
would be needed.

Which reminds me. If you ever get a tiny metal sliver in your skin, such
as a drill shaving, a strong magnet (such as one from a large speaker),
can and will often remove the sliver. I've done it! Much easier than
trying to use a tweezers and needle to dig it out (especially for old
farts like myself with failing eyesight)!