I would like to chime in on this topic, as I performed it recently. I had MUCH better luck freezing NSTs than cooking them. I left a couple in a deep freeze overnight. Pulled one out and started smacking the sides with a hammer. The tar shattered and fell out in large clean chunks. A pick or chisel works helps also as you get further in, just be careful of the wiring!
The nice thing about this method is how clean the core comes out. Minimal cleaning is required afterwards.
I tried cooking one on a hotplate outside. It was messy and dangerous and did not work well for me. Soaking in gasoline didn't work well either, but I only waited a week or so.
-JJ
Sent from my HTC Oneâ?¢ X, an AT&T 4G LTE smartphone
----- Reply message -----
From: "Tim Flood" <tfloodrr@xxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Subject: [TCML] NST Repair
Date: Wed, Nov 6, 2013 7:43 AM
Thanks Dave. I will give that a try. There is a "country store" just down
the road from where I work.
Tim Flood
On Tue, Nov 5, 2013 at 10:09 PM, Dave Halliday <dh@xxxxxxxxxxxxxx> wrote:
> I would build a wood bracket to hold the transformer upside down suspended
> over a disposable large aluminum roasting pan.
>
> Set it in the oven and gradually up the temperature until the tar starts
> dripping out. Keep it there for a couple hours.
>
> I would pot it in mineral oil. You can get this cheap from any "country"
> store that sells horse and other critter stuff.
>
> Vaseline can leave pockets of air.
>
> Dave
>
> > -----Original Message-----
> > From: tesla-bounces@xxxxxxxxxx
> > [mailto:tesla-bounces@xxxxxxxxxx] On Behalf Of Tim Flood
> > Sent: Tuesday, November 05, 2013 06:25
> > To: tesla@xxxxxxxxxx
> > Subject: [TCML] NST Repair
> >
> > I heated the two 9/60 NST's in an oven hoping to repair any possible
> > internal shorts. Luckily, this was done at an oven here at
> > work. About one
> > third of the tar boiled out exposing the upper portion of the
> > windings,
> > etc., and leaving slumped areas with porosity holes.
> >
> > The questions are should I reheat the transformers at a lower temp. to
> > close up the holes then replace the lost tar with vaseline?
> > Melt out all
> > tar and refill completely with vaseline? Replace the
> > transformers and not
> > go through the above.
> >
> > In the meantime I'm starting on a completely new one.
> >
> > Thanks in advance for any advice, and yes I probably did
> > something wrong
> > when heating the transformers.
> >
> > Tim Flood
> > _______________________________________________
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> > Tesla@xxxxxxxxxx
> > http://www.pupman.com/mailman/listinfo/tesla
>
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