Hi Cal – There are lots of beginners here – I think I’ll be one
forever – I learn something new just about every day… A heat
sink is anything that will draw heat away from the object you are
heating – it can be a pair of tongs that you use to maneuver a
piece of metal while you are soldering or even the mesh screen on
top of the tripod…
Solder will go where the heat goes – if your solder recedes,
then draw it back where you want it by moving the torch from
where the solder is to where you are wanting it to go. Sometimes
a solder pick will help spread it around as well.
There are a number of materials that you can use to keep solder
from moving and undoing all of your work: yellow ochre, liquid
paper (the water-based kind only), red rouge.
Other things you may want to consider when you have multiple
soldering operations in one job is whether you can use binding
wire to hold your pieces together and do multiple steps at the
same time; another thing to consider is starting with hard
solder and stepping each soldering operation down to medium,
easy, etc. Each of these solders flows at a different temp,
which may allow you to do more than one solder step and
controlling it through the heat of your metal.