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Re: NST insulations



> Original Poster: "Christopher Boden" <chrisboden-at-hotmail-dot-com>
> 
> Having never de- or Re potted an NST I have a few questions :)
> I have 3 15/60 Jeffersons (the baby-blue painted ones) filled with the
> standard Black Tar. They are all dead from Tesla Duty, most with one side
> toast.
> 
> 1. Is a hot-plate suitable for cooking them? Other ideas? The oven is NOT an
> option :)

I just depotted another 12/60, and one 750 Watt hotplate wasn't getting the
job done, so I ended up using two.  I put the transformer upside down on an
old BBQ grill and applied one hotplate to each side wall of the NST case.
It cooked for 4 hours before I was satified it was empty enough.

> 2. Can I do this without stinking up the house?

No. Your house would likely never recover from the smell.  Outside is the
only option, and even then it's difficult to breathe around the baking
tranny.  The tar has lots of nice carcinogens too.
 
> 3. How do I remove the shunts?
> 4. How do I identify the shunts?

Cut them out with sheet metal scissors.  On the jeffersons, they are not
separate pieces, but little "tabs" on the main core pieces.

> 5. How many can I remove without toasting the thing?

Go for the conservative 120mA unit, if you ask me.  Otherwise you risk
melting the insulation off the primary coil.
 
> 6. If Vasoline is used, how do I make sure to fill all the air spaces?

The Vasoline should be fully melted until clear, in a double-boiler.

> 7. What are other good potting compounds? I would prefer something easy to
> work with, and not liquid.

I used paraffin from the grocery store.
 
> 8 Is it better to keep it in it's original case, or would somehting like a
> 5Gal bucket be better?

When I used the hotplate method, the heating warped my NST case in horrible
ways.  I suppose I could reuse it, but it would be ugly.  My first repotting
ever was of a 15/30, and I repotted it in a 1 gallon paint can with the
bushing on top. It was the "mini-pig".

-Adam
adamsmith-at-mediaone-dot-net