Freeze it with liquid nitrogen and break the goop off (proper PPE of
course). I hear they use that technique to separate rubber from metal in
shredded tires.


RoyJ wrote:

That's what I thought at first but when you pour the goop in, the
temperature drops rapidly, the core never sees the high temp. When you
reverse it, the leads would see the overtemp. I can get at all the
leads, I could just saw the case apart and leave it potted.

wrote:
On Apr 21, 8:51 am, RoyJ wrote:
I picked up a 600 watt power pack for running those little sidewalk and
yard lights. Photo sensor is shot, transformer is massive. Salvage time.
But the whole transformer is potted in some sort of black tar. I scraped
some of it out, looks like it softens at 200F, goes semi liquid at 250F,
and fully liquid at 275F. Easy enough to rig a tent over a catch basin
and aim a heater in there but what about the temp rise on the wires? I
would need to run it at the 250F to 275F (120C to 135C) range for
perhaps an hour to get all the goo out.

If it survived the temperature while being potted, it should do the
same in the reverse direction......give it a go, see what
happens..........or, manually chip out enough of the gunk to get to
the secondary transformer leads and hook to them...
Andrew VK3BFA.