Re: Neon repair
> I have noticed many posts saying shorted neon transformers could be
> by removing the tar which has carbon tracks from an arc.
> I have 4 bad neons I would like to try and bring back to life. Before I
> this I have some questions.
I've tried both the freezing and the heating method, in either case, I first
cut open the case with a wood chisel. I saved the insulators by cutting the
sec. wire going to the insulators from inside of case, scooping out the tar
near the insulator with a heated screwdriver, and pulling out the insulators
after "tearing" the case away from them.
I found it harder not to damage the windings using the freezing method
because the hardness of the frozen tar transmitted the force of the chipping
blows to the windings.
For the heating method, I put the transformer in the oven for 1 hour, but I
kept the temperature very low--about 150 degrees. At this temp, there seems
to be no danger, and the tar is softened enough that in can be pried loose
without damaging anything. If the tar begins to harden before I'm finished,
I use a hair dryer or heat gun to "spot" heat the troublesome areas. Using
this heating method, the entire tar/winding structure remains "flexible" and
seems resistant to damage.
After removing 90 percent of the heated tar using a screwdriver or other
tool, I then soak the whole assembly in a covered gasolene container--yes
kerosene would be safer.
Then I dismantle the core and soak the individual parts, and sec. coils. I
use an old toothbrush to scrub the tar away from the edges of the windings.
Finally I re-assemble the transformer and install it into a wooden box with
safety gaps, input and output terminals, protective caps and chokes. etc,
mounted to the exterior of the box.
Still, all in all, the whole thing is a horrible, messy, smelly, time
consuming job. The only good thing about it is it works!