Can i use the silver solder in a pinch?
Silver solder is a poor match for white golds. The color is wrong,
the strength may not be as good (though It’s probably OK), and the
joint will tarnish over time. Also, silver solder is softer than the
white gold, so when you polish it, or even just with wear, The solder
will tend to polish out of the seam, leaving a depressed line in
addition to a color difference. All in all, it’s probably worth the
money to get some suitable white gold solder rather than going the
cheap route. If you had to make an emergency repair or something,
and silver solder is all you had, it would do the job of joining the
parts. But the work would not usually be considered up to
professional standards. Your choice. Now, if you were joining silver
to white gold, then silver solder is an acceptable solder to use.
It’s softer than white gold, but also more ductile and malleable, so
joints in dissimilar metals like this would have fewer problems with
cracking or stress from different thermal expansion rates.