On 25/3/20 12:12 pm, whit3rd wrote:
On Tuesday, March 24, 2020 at 5:10:19 AM UTC-7, 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.

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 by designed-in self
inductance, core saturation, etc and can't easily be tweaked to
deliver higher current in a short pulse.

The current ought NOT to be delivered in a short pulse (it has to
penetrate the metal pole pieces as well as the magnet, which takes some time)
which is why it has to be a DC welder. The induction is not just 'amps',
but is 'amp-turns', so a few turns of wire will multiply the effect of the
welder current accordingly.

Also their rated current is
at 20-25V which doesn't allow for much wire resistance. At 20V the 0.1
Ohm resistance of a coil wound with 100' of 10AWG copper wire...

I'm thinking it's more on the order of five feet of wire, maybe 5 or 10 or so turns
around a circa 1.5" bar (it just has to be as thick as the pole pieces it's being held
against). I'd consider using one of my auto jumper cables instead of ten-gage.

Flattened copper water pipe is better. Tightly packed square section is
better still (approximately square winding cross-section, too).