On 24/03/2020 23:31, Jim Wilkins wrote:
"Clifford Heath" wrote in message
...
On 24/3/20 11:10 pm, Jim Wilkins wrote:
"whit3rd" wrote in message
...
On Tuesday, March 17, 2020 at 11:06:10 AM UTC-7,
wrote:
On Sat, 14 Mar 2020 21:25:20 +0000 (UTC), Cydrome Leader
The alnico
magnets in old and/or inexpensive mag bases were/are magnetized
after
assembly. This takes a LOT of current. I have seen the setups for
doing this and they are not trivial.
There's a two-part magnetization process for alnico, you have to
observe the
built-in (at ceramic-firing time) polarity when you apply current.
It WILL magnetize one direction, not the other.

Usually, metalworkers have access to high DC current sources from
Lincoln, Miller,
Hobart, etc. and that's what it'll take.
Arc welders inherently limit short circuit current...
What about a spot welder, hooked up to a fat coil of copper tube on
a magnetic core?
I've used a pedestal spot welder on sheet steel and don't remember the
metal being pulled into the current loop or otherwise disturbed when I
stepped on the pedal.


I thought about a spot welder as mine is about 6000A hand held unit but
it's AC so wouldn't be any good. Mine does exhibit a bit of buzz and can
cause near items to buzz a bit but the magnetic field definitely upset
my Swatch watch, not permanently but I had to read the instructions to
reset the time, I took it off after doing that a few times.