Hello Rob Jupp,
There are several possible reasons for your problems. Any special
reason you are using brass rather than silver? I've not soldered
brass with silver solder - Judy Bjorkman, can you comment?
In general, this applies to any soldering (actually
The joint must be clean - freshly filed is good - and closely
fitted. It sounds like your fit is tight enough for solder to flow.
Picking up the solder balls on the pick is a matter of practice. If
the solder balls move from the force of the flame, turn the flame
down. You'll want to heat the pick a bit - I put the pick near the
solder as it melts. Touch the point of the pick to the solder ball a
second or so after you melt it - the ball should barely adhere. If
the solder ball is too hot, it'll sort of bounce off the cooler pick.
If you heat the pick too much, the solder flows onto it! Practice,
I have a friend who uses wire solder and touches it to the hot joint
rather like electronic soldering is done. She is very adept and you
might try that technique. Again, practice is key.
If the solder flows to one side of the joint, it sounds like the heat
is unequal on both sides, or that side is dirty or not fluxed. Most
likely it's uneven heat. A good exercise is to solder a small ring of
metal to a flat plate. You understand the importance of even heat,
and that solder flows toward the hotter area. Your torch becomes a
paintbrush for drawing solder around the ring.
You really don't want the solder to overfill the joint. That's why a
close fit is best. Besides, it takes more time to file off the excess
solder. Just like salting food, you can always add a bit more, but
it's difficult when you have to remove too much. Ideally, the
soldered joint is invisible.
Hope this helps some,
Judy in Kansas