When I was at college they taught us that firescale was something
that could be controlled by controlling the flame you are using and
paying close attention to you piece and the various colour changes
that occur. The takes a lot of concerntration, but well worth the
time and effort to concertrate when heating your piece.
Yes there are several fluxes out there that will help you lessen the
amount of firescale on your piece, and I certainly encourage you to
try them, but to master the control of your flame is the best and
most satifactory way of getting rid of fire scale, especially if you
are working with a piece of jewellery that does not have a lot of
metal to file and sand, ie: if your piece is narrow or of fine
My advise is to keep your flame small and reducing( well shaped but
not sharp) and watch carefully as the silver turns colour. Add as
much flux as you can without having it get stuck in places that will
be hard to clean, but silver should not go beyond a point of a dull
cherry red. I suggest that when soldering or heating, turn your
lights off in the workshop, the dull cherry red colour will glow from
beneath the surface, dont let it get to a point that you can see it
glow bright red like steel does. you are certain to get firescale at
that bright red tempreture.
Hope this helps. I have had a lot of problems with firescale in my
college years but have praticed hard to concerntrate on the colour of
the silver when heating.