For the electrical consideration, you can optain an isolation transformer from
various surplus outlets inexpensively that will eliminate that sort of problem.
Also, a GFI (Ground Fault Interupt) outlet would be recommended.
Respectfully,
Ron Moore

Moonraker wrote:
For years now, I've only used the Weller 100w Pro iron with the Temp
controlled tips. Yesterday, while working, one of the Wellers let out a
huge spark and fireball while sitting in the iron holder.

SNIP

I'm getting tired of paying $50 to $75 for these irons when they only last
5-6 months....and now I'm concerned about the electrical safety of them.