Soldering: illusive, fretful, illuminating and the foundation of
what we jewelers do.
I absolutely love soldering and create pieces that require multiple
connections, often as many as 15 on a single piece. I also teach a
3-day workshop to help others. Here are some of the basics.
1) The perfect fit. No matter how clean your work might be, solder
cannot jump over a canyon. Your bezel might look straight and your
filing precise, but stare at your connection through a loop and you
will wonder about what demons came to your bench and ravaged the ends
while you weren't looking.
Solution: Achieving the perfect fit. I may solder well, but I can't
file a straight seam worth a damn. I purchased a miter jig. This is
an expensive tool, but one I can't live without. Fabricated from case
hardened steel, insert each end of your bezel strip and file against
the jig. Perfect connection, perfect solder. Yum.
2) Soldering different metals. Some metals expand at different rates
because of their melting temperatures. The second band ring I
fabricated had a nice wiggly, sweat soldered flattened piece of
copper over silver. I tried soldering this sucker several times and
couldn't get it to fit until I bound the thing to an inch of its
life. Copper has a higher melting temperature than silver. The
experience was like trying to cook a perfect Thanksgiving turkey when
I just passed the exam on making toast.
3) Silver Solders. Here is what I have learned.
Solder from Rio Grande, Easy and Medium are fine. The Hard won't
melt if I put it under a blast furnace. It kind of blobs.
Hauser and Miller: More alloy, less silver. All around good, E, M,
H, all do what it needs to do. Color match is good. It's a good all
around solder for my students, flows nicely and easy to work with.
Hoover and Strong: Less alloy and needs more heat. They have the
best color match solder around. It takes more heat to flow, but worth
it when it does. I rate this as a minimum intermediate skill level
Gold Solders. Honestly, I don't like any American made gold solder.
I find you need a spot welder to make them flow, and they don't flow,
they sort of goo in place. I use German solder from C Hafner. It
flows, it moves, it makes working in gold a pleasure.
4) Flux. My favorite for silver is Superior Six paste flux. Jeffrey
Herman of the Society of American Silversmiths fame,
http://www.silversmithing.com/, turned me on to this. For silver it
creates a lovely bluish skin which allows me to solder and resolder,
without having to pickle each time.
Boric acid and alcohol is good for gold, as is Batterns. I haven't
worked with white gold or platinum, so I won't comment there.
5) The Great Gas Debate. One of the most hotly contested of all,
which gas is best. Well it depends, what are you doing[xxxxx] I use
propane/oxy and acetylene /air. For big stuff, larger pieces like the
6-8" size, I go with acetylene/air. For silver, I use Prips to keep
the firescale down. For smaller pieces, I like propane/oxy. Honestly,
use what works the best for you.
We also have natural gas/oxy because I was lucky enough to get it
plumbed in when the building was remodeled. However, I didn't find
out in time that you need at least 5 psi of gas to work with the
regulators. The G-Tech gas booster was a life saver.
6) Torches: We use the Smith torch tips for acetelyne/air, the
Little Torch and the Meco Midgett.
7) Fire brick: ceramic vs solderite vs firebrick vs charcoal. This
does get confusing. A few do's and don'ts. Don't use past flux on
charcoal. It gums it up. Solderite boards don't like it either.
Firebricks are fine. Clean your soldering surfaces. If you have a
dirty surface, you will take away heat trying to bring everything up
to temperature. Start clean and end clean.
8) Tweezers are handy, they also act as huge heat sinks. Tip, heat
the tweezer by the tip. You don't need to get it bright red hot, but
by doing this the steel in the tweezer takes a while to cool down and
your soldering area stays nice and hot.
9) Learn to use your flame in your good hand and teach to pick and
place in your other. Why? Flame control is the essence of good
soldering. Once the pieces are in place, you won't have to switch
10) Heat control. I often find my students taking out a oo Smith
torch and trying to solder a giant piece of metal. Unless you have
nothing else to do for the rest of the day, there is no way that
anemic flame will raise enough heat to solder. Rule of thumb. If you
can see your piece from a foot away, use a bigger torch tip. If you
need to squint, a smaller one is best.
Your flame doesn't have to do all the work. Build a little oven with
heat bricks, or take away heat by burying some of that chain or piece
in your pumice chips.
Soldering is a balance of heat, hand, eye and focus.
M E T A L W E R X
50 Guinan St.
Waltham, MA 02451
Ph. 781/891-3854 Fax 3857
Jewelry/Metalarts School & Cooperative Studio