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Solder age


#1

Can silver solder go bad with time? I am trying to solder and am
having alot of trouble - the pieces just aren’t ‘sticking’. Please
help!

Ariella Merklin
www.Ariella-Design.com


#2
Can silver solder go bad with time?

The solder may be tarnished or oxidized thus introducing
contaminants. Silver solder needs to be shiny clean before you use
it. For wire solder I use synthetic steel wool to polish it. For
sheet solder I use the 3M wheels to polish a section before cutting
snippets.

I also think flux gets bad after a couple months if not kept sealed.
I keep a small (2 oz?) squirt bottle on my bench and the rest sealed
in a dark cabinet. I notice when the squirt bottle gets low
soldering becomes difficult so I wash it and refill it with fresh
flux. Soldering always goes much better after that… or maybe it’s
just taking a break and re-pickling things… :wink:

Rick Copeland
Silversmith and Lapidary Artisan
Colorado Springs, Colorado
http://home.covad.net/~rcopeland


#3

Thanks for all your help and advice regarding the soldering. I’ve
cleaned my solder and it got somewhat better, but still not every
piece is soldering everytime. Like it should. I guess it could be the
flux - when flux gets bad, is soldering sporadic? Or, could it be my
flame? Sometimes when I heat the piece, it gets so hot, the piece
turns red. And I know that’s too hot. But the solder still doesn’t
flow well. (By the way, I am trying to solder jumprings onto a round,
casted piece of silver about 14mm in diameter shaped like a cone).
What sort of flame is best for that type of soldering. I am using a
Little Torch. Any more help and advice is much appreciated! Thanks!!


#4
    Thanks for all your help and advice regarding the soldering.
I've cleaned my solder and it got somewhat better, but still not
every piece is soldering everytime. 

99% of the time it’s because either the joint or the solder was not
clean enough. If at the first soldering attempt, the solder did not
flow completely, pickle the piece, scrub it down, reflux, reheat the
piece and most likely the previous solder will finish flowing. I
think you’ll find that really squeaky clean joints and solder will
flow most every time without problems.


#5

Hi, Ariella, This problem occurs fairly often with my students. What
I find is that soldering is about heat control and cleanliness. If
you dip the whole piece in boric and alcohol, by the way, this seems
to help remove oils and such. But what is often the problem for the
less-experienced solderer is heating too slowly and/or too close to
the joint. If you use a small flame to heat a big piece, oxides have
time to build up and interfere with the join. Too large, of course,
and you melt things. With a relatively heavy (cast) piece and a small
piece (jump ring), you need to heat that whole casting, so you choose
your tip to go with that piece, and heat well away from the join.
Heating fairly fast keeps the metal cleaner. When you start using
a bigger tip, you will likely have a few “learning experiences”, but
how are you going to know what is too hot unless you go there? My
mantra is “It takes what it takes”. HTH!

–No�l


#6

Hi,

    (By the way, I am trying to solder jumprings onto a round,
casted piece of silver about 14mm in diameter shaped like a cone).
What sort of flame is best for that type of soldering. I am using a
Little Torch. 

Sometimes it’s difficult to identify the cause of a soldering
problem without actually seeing the job/operation. With that caveat,
I’ll take a stab at the cause of your problem.

I’d bet your problem is caused by too little heat. Even with the #5
tip, soldering silver can be problematic with the Little Torch. The
flame is hot enough, but even the #5 tip doesn’t put out enough heat
per unit of time (BTU’s) to get & keep a relatively large piece of
silver at soldering temp. The flame is just too small.

You’d probably have better results using a larger acetyline/air
(Prestolite etc) torch. Even with the smaller tips, they produce a
larger flame with the necessary heat content.

Dave


#7

Hello Orchidland, The question about solder going bad made me think
about old solder with cadmium. Can anyone give a general date after
which most solders were cadmium-free? I ask because I still (yes,
STILL) have some solder that was purchased when I was in college,
late 60’s. It has occured to me that it probably contains cadmium,
but I don’t know. (Obviously, if I still have it, I use it seldom
and can easily put it in the scrap.) Hey in those days, students
still handled mercury in chem lab and we used carbon tetrachloride
in insect killing jars. Times have changed. Judy in Kansas, where my
mums are still gorgeous after a hard freeze.

Judy M. Willingham, R.S.
B.A.E. 237 Seaton Hall
Kansas State University
Manhatttan KS 66506
(785) 532-2936 FAX (785) 532-6944


#8

the problem is probably related to 1) the little torch and its small
flame 2) the mass of the piece you’re soldering to 3) soldering
technique and maybe 4) flux which has become too thick from
evaporation.

General soldering technique dictates that both pieces be brought up
close to soldering temperature before you actually begin the
soldering process.

I haven’t used a little torch for some years, but I remember some
things. You probably want to be using the tip of the inner cone part
of the flame and not the softer part further out which tends to
oxidize the metal.

Personally, I think I’d partially melt the solder onto the heavier
piece, then hold the jump ring in tweezers in such a way as it is
heat-sinked (don’t forget to file a flat on the jump ring where it
will contact the piece being soldered to) and gently press it into
the solder as the solder gets up to a high enough temperature to
complete its flow. You probably want to be directing the flame point
toward the heavier piece, just allowing enough heat to get to the
jump ring to allow it to come up to soldering temperature but not so
much that it melts…

Another point, don’t overheat the solder. If necessary, hold your
solder pic against the solder as it comes up to melting temperature,
heat-sink it. If the solder overheats, it can develop an oxide
coating, and maybe even burn out some of the alloying metals.

If the flux is too thick, it will form a barrier, so if your flux is
old, it’s possibly in need of some additional water to thin it out.

One more thing, if you’ve applied thick boric acid solution, you may
need to remove some from the area being soldered as it can form a
barrier just like overly thick flux.

Jeffrey Everett


#9

Ariella, There could be several thing preventing the solder from
flowing but here is a couple of possibilities.

One, sometimes when you use a little torch to heat a large or heavy
piece, you cause undue oxidation because of the prolonged heating
process. It is best in such situations to get in fast, heat fast and
get out. Second, you may be putting heat directly on the solder
while also trying to get the sink up to temp. If you stay on the
solder more than a few seconds and the sink is not at soldering temp,
the solder itself can oxidize and form a film that keeps it from
flowing.

Try this, if you cannot get a quick heat up, periodically add some
self pickeling flux to the solder and around it. Keep the heat away
from the solder until perhaps the last few seconds. Use a larger tip
(possibly a multiple oriface tip) to get faster heat up. Under these
conditions, the solder should flow quickly. Nine times out of 10, I
find my students have not used a large enough tip nor have they
heated the sink sufficiently.

Hope that helps…Cheers from Don at The Charles Belle Studio in
SOFL where simple elegance IS fine jewelry! @coralnut2