[TheForge] Re: Simple, intriguing demo?

[Mike Spencer]

> In a week, NJBA will be demonstrating at the Newark Mini MakerFaire.
> (Look it up if that means nothing to you.)
> [snip]
> (1) To demonstrate that forging involves radical change of the shape
> of the workpiece.

As a starter with novices, say jr. high, university age and up, I like
to use this to make the point, first off, that iron is *soft*.

Drop a 3' piece of 1/4x1 on the floor from over your head.  Clang!
You usually think of iron as hard, refractory.  In the hands of the
smith, iron is soft and mushy.

Ask how you make a hole through that piece of 1/4x1.  Drill it:
obvious.  Not for the smith.  Heat up the 1/4x1 and punch a 1/4" hole
in less time than it would take to set up the drill press.  (You can
make that a 3-handed job to involve the watchers if you think someone
can hold the workpiece or a helved punch safely.)

Now ask: What if you want to make a 1" hole though it?  Show a 1"
punch.  Can't drill it *or* punch it 'cause you'll cut it in two.

Then I slot punch (not chisel) a slot, open it with a tapered punch,
round up on the horn to make a (roughly) 1" hole through a 1" wide
piece.  You have to think of iron as *soft*.

Now, I say, what if you want to make a hole through that 1/4x1 *the
other way*?  The edge way?  Only a tiny drill would work, nothing even
*near* 1".  There's no way, right?

With the opened-slot eye hot, put it in the vise and give it 180 of
twist.  Now another rod (albeit smaller than the diameter of the
original eye) will pass through the eye in the 1/4x1 bar the flat way.

Makes the point about soft & mushy versus hard and refractory.


FWIW,
- Mike

-- 
Michael Spencer                  Nova Scotia, Canada       .~. 
                                                           /V\ 
mspencer at tallships.ca                                     /( )\
http://home.tallships.ca/mspencer/                        ^^-^^