Re: NST insulations

To: tesla-at-pupman-dot-com
Subject: Re: NST insulations
From: "Bruce Ives" <brucei-at-bellsouth-dot-net> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
Date: Mon, 06 Mar 2000 12:06:55 -0700
Approved: twftesla-at-uswest-dot-net
Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

<snip>
>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 :)

Should work fine.

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

Yeah, take it outside


>3. How do I remove the shunts?

I understand with Jefferson  it may require drilling and /or grinding


>4. How do I identify the shunts?

pieces of iron between  the primary and secondary coils. When you have the 
core depotted and cleaned they will be easy to see and identify


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

You'll have to experiment with it. Use an ac milliampere meter and a 
variac. you should be able to get about 3X rated secondary current without 
putting too much of a duty cycle on it.


>6. If Vasoline is used, how do I make sure to fill all the air spaces?

Vaseline melts too!


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

Paraffin wax, epoxy


>8 Is it better to keep it in it's original case, or would somehting like a
>5Gal bucket be better?

Each has its own advantages and disadvantages. whatever works best for you.


>9. Can wooden forms be used to place and center the core in a bucket? (I
>have seen this done with BIG transformers in oil)

I don't see why not as long as the wood is very,very dry



>thanks guys.
>
>Chris B.

Good luck
Bruce