can you give me tips on making a symmetrical, smooth ball?
Jean, get yourself a charcoal block, from a jewelers supply house.
If they happen to carry the european style compressed blocks, which
are a bit more costly, these will last longer. Now, using a twist
drill (which you can turn just in your fingers, for this, if you
like, sized to the size of wire you’re using, drill holes through
the charcoal block, or at least, into it deep enough to hold the full
length of the headpin you’re making. With a ball bur, or small
round object of your choice, carve a small hemispherical cavity into
the block at the end of the drill hole(s). Drop a wire into the
hole, leaving the amount of wire needed to form the ball you wish,
sticking up. This length will need to be determined experimentally.
Now, and this is the solution to your pitty ugly balls, apply some
hard soldering flux, such as batterns, or the various types of silver
brazing flux that are available. It doesn’t take a lot to do the
job. Just a little will do it. Now, when you melt the wire end down,
it will melt down into that cavity to form a ball, with the block
insulating the bottom of the ball and junction with the wire enough
to keep it from sucking up more metal from the end of the wire. The
cavity will also keep the ball centered on the wire, spherical at
the bottom, or close to it, and will allow you to make, if you wish,
larger balls. The flux, when it melts, coats the melting and molten
silver preventing absorbtion of oxygen, and it’s subsequent
evolution again from the solidifying metal, which is one significant
cause of that rough pitty effect. It also avoids much of the
oxidation of the copper, which also gives you a rough ball. The flux
residue when you’re done, will need to be taken back off with pickle,
or even just boiling water. When you’ve done a bunch of these, the
charcoal block will get pretty rough itself, and you may need to take
a file or some coarse sandpaper and resurface the top of the block,
after which you’ll need to recarve the little hemispherical
depressions.
You can melt as fast as you like. Silver won’t be suffering from
heat shock. It’s not glass. It’s just about the finest conductor of
heat there is, so heating and cooling is uniform even if quenched in
water, which is also something you can do. The silver should be
cool enough to no longer be glowing, but given what you’re doing,
you’d be hard pressed to quench too quickly in any case. If you
quench in pickle, beware of spatters. Better to quench in water,
then pickle in a seperate operation. if you need to.
Hope that helps.
Peter Rowe