Heat sink

Thanks to all of you who responded to my request about soldering
the jump ring between two parts of the pendant. They were very
helpful suggestions and I greatly appreciate your time.

Is it ever advantageous to use a heat sink? When I first started
making jewelry a year or so ago someone mentioned using heat sinks
for some process and I have not determined where or when to use
them. Any suggestions? I wondered if they are used in soldering
additional pieces onto a large section.

Thanks, Sue Danehy

Hi Sue, If you need to solder something near a stone, you can
place a heatsink between stone and solder point. This will
sometimes work and if it takes too long to solder or if the stone
is too close, sometimes get you into trouble. good luck, Tom Arnold

Hi Sue,
I heat sink all the time. If I don’t want solder to flow on a
ring size up, I just use my solder pick on the other seam to keep
it from flowing. It doesn’t take much to heat sink an area close
to where you are soldering, just practice with the solder pick and
a jump ring where the solder has jumped to the side of the seam.
Rest the pick on the side where the solder is and the heat should
draw it over to the seam. Careful not to over heat and melt the
jump ring. Practice.
Janine in Wet California

You cn use a heat sink to isolate the joint when soldering a ring
for resizing. If you use a third hand with two arms, place one
clamp on either side of, the joint and to be really safe lower
the ring until the stone is in a shallow dish of water, then
solder. This of course is for rings having heat sensitive stones.
Can also be used to solder a joint that is close to another solder
joint to keep that one from opening up, such as when one joint of
a piece that hs been soldered in to enlarge a ring breaks and has
to be resoldered. Jerry in Kodiak

Cross locking tweezers make great heat sinks… soldering weights
with a large contact surface area make good heat sinks. Repair
jewellery and mechanical devices (catches, some hinge types) almost
require heat sinking. The Jewellery Repair Manual, and Cheap
Thrills in th Tool Shop are good books to refer to. Solder flow
inhibitors are other good alternatives: white out, rouge, and
whiting are all good. Highly localized heat is cool too, i did a
thing with glue on it with a TIG Welder (50,000 degrees farenheit)
and it melted the glue only within a 1" radius (big piece, bad
sequence of process)

hope this helps.
Robb Mitchell

Dear Sue

I assume that you are considering using heat sinks in order to
keep previous solder joints from flowing or to keep thin parts from
melting. I find heat sinks helpful when used in combination with
other methods.

In silver when soldering small parts to a larger section,a heat
sink such as clamping tweezers, work best when attached to the
small parts in preventing a previous joint from flowing. I also use
other methods, such as switching to lower temperature melting
solders with succesive joints, positioning previous joints lower
since heat rises, coating previous joints with yellow ochre and
embedding previous sections in a soft soldering board or wiring
them in place.Often I use several methods together. Silver is more
difficult to work with in succesive soldering steps than gold,
since it transmits heat throughout the piece.

By the way , I’ve had great success using yellow ochre in
preventing solder flow on gold. I know many ‘purist’ goldsmiths
frown on this, but I say if it works do it.

Hope this helps,Tom Tietze

Yes, there are times when one wants to use a heat sink . . . when
you don’t want to melt a small item. If you are soldering the
large to small (or small to large) piece, and you don’t want to
melt the small piece, put the heat sink on that, and then heat both
to the temp at which the solder will flow.

Have fun!

Hey Tom, We met five or six years ago. I was looking for a new
situation. A year or so ago I was in need of an overnight platinum
casting and went over to your Gaithersburg shop only to find it
occupied by some unrelated business. Good to see you here. An
international forum. Yet it seems to be a very small world.

Bruce D. Holmgrain
e-mail: @Bruce_Holmgrain
http://www.goldwerx.nu
phone:: 703-593-4652

Hi, The family opened a store called Facets in Arlington, Va. Stop
in and say hello. That goes for any of my internet friends. Tom
Arnold

I am working on a particularly difficult bug where the six legs and
two antenna are all very close together. They all finally got
soldered onto a particularly heavy cast body, when one of the more
inside legs broke off. I would like to use something as a heat sink
to protect the other legs while repairing this one. Ochre has not
been very successful, and kool jewel is too messy. Would brass or
copper act as a heat sink? What if it were ochred as well as the
parts protected by it? Any other suggestions? Any help would be
appreciated ASAP as I’m due to finish it this week(!)!
Many Thanks Sandra

What metal is the piece you are working on? Silver is a very good
conductor of heat and would work best if you could prevent the
solder from flowing unto it. If your piece is silver I suspect you
will have to use a lower temp solder as the whole piece will soak up
the heat.

Dan Wellman

Hi Sandra: I have always had good luck using Liquid Paper–it is for
correcting mistakes on typed paper, but does a great job keeping
other soldered joints from flowing when you are working on one close
by them. The Kendall Company makes a product called Webril Handi-pads
that I wet and wrap around areas to also act as a heat sink. After I
apply the Liquid Paper, I either wait till it dries, or pass my torch
over it till it dries. If needed, I then wrap part of the project
with these wet pads. To get the Liquid Paper off, I use a brush on it
under running water, then pop it in the pickle. It is not necessary
to brush it off under water, but the pickle stays a little cleaner.
Barbara

I don’t think of ocher as a heat sink. It’s used to prevent solder
from reflowing during multiple solderings. I would use something
physical like pumice chunks to shield the legs. For a heat sink, I
would use something that I could clamp on the tiny parts such as
cross locking tweezers or well rusted baling wire.

Marilyn

Would brass or copper act as a heat sink?  What if it were ochred
as well as the parts protected by it? 

Hi Sandra,

Just about anything will work as a heat sink, including brass or
copper. The problem with them, however, is that you could unwittingly
solder them onto the piece! My suggestion is to use stainless steel
binding wire. It would be hard to solder it on by mistake even if
you were trying to but, to be extra sure, just heat it till it turns
black. The oxide will inhibit solder flow. Then wrap it around the
joints/legs/antennae that are at risk. And don’t worry about throwing
it in the pickle. Stainless steel will not react with it. I put
stainless steel tweezers and binding wire in my pickle pot all the
time.

Second choice: Use anything made of regular steel (tweezer tip,
shaft from a broken drill bur, nail or screw or washer) – but don’t
throw that in the pickle! Good luck.

Beth

Personally I haven’t tried this particular method (I have done sort
of–with a setup to hold parts while soldering), but I saw a fellow
paint on a thick slurry of plaster of Paris on everything except the
part that had to be repaired, let it dry, then soldered. Stuck it in
a bucket of water afterwards to soak off the plaster, brushed it with
a wire brush, then pickled it. Might work if nobody comes up with a
better solution.

Sandra, Have you thought of drilling holes for the ends of the legs
and such . It could be you need a little peg on the ends for this
purpose. Make a tight fit so they stay with out help and soldering
them in one sitting.I would think just heating the big bug body will
be enough to heat the legs and such for the solder to flow. I do not
think any heat sink will help. aluninum is usually used for a heat
sink in minor heating situations.

Michael

As a student, I once tried using aluminum as a heat sink on a cast
sterling piece upon which I was working. The heat from my
prest-o-lite torch caught the piece of aluminum on fire resulting in
a magnificent fire! On the re-created piece I surmised that titanium
would be a better alternative as a heat sink as it’s melt temp is
far higher than aluminum. I was correct in that assumption, however
I couldn’t achieve flow temp with my prest-o-lite. I switched to a
Little torch. Somehow I caught the titanium fire as well. It burned
fantastically hotter & brighter than the aluminum!! Everyone in the
studio was told to evacuate immediately, and the fire lit the entire
room like a 4th of July flash pot firework. I now use a titanium
solder pick with both my little torch & water torch, and I haven’t
had a problem with fire as of yet. Practice in my case has made
better, but not yet perfect. I now use Rio’s chill gel &
thermo-guard as heat sinks. They work OK. Best of luck!

 As a student, I once tried using aluminum as a heat sink on a
cast sterling piece upon which I was working. The heat from my
prest-o-lite torch caught the piece of aluminum on fire resulting
in a magnificent fire! 

It could have been magnesium or aluminum with magnesium.Magnesium is
very flammable.In my machine shop class the teacher demonstrated
this point by dropping a spark on a small pile of magnesium shavings
.It exploded immediately.

Aluminum is a metal with a lower meting point than most jewelry
metal work.It is very conductive of heat and thus a good use for a
heat sink at lower solder temps. I do not usually use heat sinks for
any solder applications other than sizing rings with In
most cases proper design and approach to construction will give the
best results with out the use of heat sinks.

As a test, does any body want to try to catch a piece of aluminum on
fire?

Michael

Try this one then for a spectacular effect.

Pull apart until “fluffy” a piece of fine steel wool. Hold it in a
pair of tweezers and set light to it, outside, over a bucket of
water!

Many metals if finely divided will react to heat and oxygen.

Tony Konrath