[Amps] Transformer oil?

[G.Johansson]

Hi!

Have a nice transformer.. Large n' bulky etc!
2.5 kV Secondary..Low R's etc

But is only half-filled with X-fmer oil.
Used in the Swedish Army long time ago.

I'm suspecting it has PCB's in oil,
so kind of little bit unwilling to pour it out....

So the question is :
Is it possible just to top 'her' up without removing
the old stuff?

What will happen if two different oils are blended 
when it comes to boiling temps etc?
Xfmr oils often has a low boiling temp type 140 c
(Guess the thing has to work when it's cold outside aswell
without going into a half-liquid state?  ;o)
as opposed the oil I were thinking of..compressor oil,
or something like that.

The compressor oil is somewhere around the 190's or more.

So what do you folks think?

1) Top her up with another oil?
2) Remove PCB-oil, give her compressor oil?
3) Blend it like Whiskeys?


73's
Joe aka SM0EJR