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[Beginners' Corner] Soldering help


#1

Help, I am just learning the art of silversmithing and am having trouble
with soldering. Ive gotten the hang of soldering small things but Im going
crazy trying to solder a small piece to a larger piece. Ive tried heating
slow, fast, tons of flux, not enough flux, etc… Ive read tips on the
subject, but they are all fairly general. Is there anyone out there who
has any tips for me? Thanks, Leta


#2

Ahh…the soldering problem. Small pieces to larger pieces.

When you heat your two pieces together, you must consider, that the
smaller piece will heat up first. Solder is attracted to heat, not the
flame and thereby gravitates to the hotter (in this case) smaller piece.
Heat the larger piece first and the smaller second, maintaining most of
the heat on the larger piece. The solder should flow correctly.

Karen Christians
Fly Fish Design
282 Lexington St.
Woburn, MA 01801

@metalart

Current Artwork:


#3

Leta,
Try heating from the bottom of the larger piece… and apply heat the to
the smaller piece either with timed ‘hits’ with your torch or with a second
torch…You have to have both about the same temp to get a good flow…I
have had great success with heating from below with the larger piece
supported by 2 firebricks and the torch hitting in the space in between…
and don’t be afraid if you get it too hot…a fuse will work too :slight_smile:
(although avoid the dripping of melted )

good luck…
Terry Swift (Corydon, U.S. - midwest where we sent our storms on to the
east…good riddance :slight_smile:


#4

I had this problem until I switched to acetelyne and a relatively large
torch (Prestolite) What are you using?

Are you soldering in a dimmed area so you can see the color change in the
silver??? If not, turn off your lights, and watch for the metal to turn
reddish. Your flux should start off pastey looking and then bubble up,
after that it should turn clear, that’s when you should apply your solder
and it should run immediately!

. . . you should HEAT your largest piece first . . .
apply the solder to the smaller piece, reheat your larger piece, pickup
the smaller piece with tweezers, get to the area of your torch where your
smaller piece will heat a bit, and apply the smaller piece when the flux
turns clear.

Have fun!


#5

Leta,

I think one problem may be getting enough heat to the large piece as it is
a large heat sink. More heat has to be applied to the larger piece and if
it is really of some size, you will need a large heat source. Once the
big piece is pretty hot, get a bit of heat to the small piece and it
should flow.

If you have had problems of the solder not flowing, especially to the big
piece, heat is almost for sure the problem. Practice on some sheets of
similar size to what you are working on so if you melt it it is not a big
loss of bench time.

My 2 cents worth.

John

John and Cynthia/MidLife Crisis Enterprises
Maiden Metals/C. T. Designs/ Bloomin’ Wax Works. etc.

PO Bx 44, Philo
CA 95466
Ph 707-895-2635 FAX 707-895-9332

The playfulness of the Universe
is reflected in the dance of the stars!


#6

Hi Leta,
What kind of a torch are you using?
If my flux is still wet, I start with a very small flame and feather it
around the piece until the flux is dry and then make sure the solder
snippets are all in place. Then, I pick up the piece with a pair of
tweezers and heat from the bottom using a fairly hot flame. If the solder
doesn’t flow in a few seconds I turn up the flame, always moving the torch
back and forth a little under the piece concentrating on the place to be
soldered. (with silver you usually have to heat the whole piece) This
almost always works. If it doesn’t it may be your torch doesn’t get hot
enough, or the metal needs to be cleaned. I use a little torch with
propane and oxygen. I have used an acetylene/air torch and started out
with just a propane torch from the hardware store - all of those things
will work but i love the little torch.

Jan http://www.designjewel.com


#7

Help, I am just learning the art of silversmithing and am having trouble
with soldering. Ive gotten the hang of soldering small things but Im
going crazy trying to solder a small piece to a larger piece. Ive tried
heating slow, fast, tons of flux, not enough flux, etc… Ive read tips
on the subject, but they are all fairly general. Is there anyone out
there who has any tips for me?

Leta - When I used to teach, I would tell my students to think of the two
pieces of metal as containers. You then must fill both containers at the
same time with heat, so they both fill to the top at the same moment. In
plainer language, you must heat the large piece much more than the small
piece. They must reach soldering temperature at the same time, or your
solder will flow onto the hottest piece and not connect them together.
You must also make sure that your joint is clean and the pieces fit
together without any space between them. If you have heated and pickled a
piece of sterling several times you have built up a layer of fine silver
on the surface. This layer is very unstable and will pull off completely
if over stressed. You can remove this layer by sanding or filing the
surface.

Good Luck. – Steven Brixner - Jewelry Designer - San Diego CA
USA
@Steven_Brixner3
http://home.worldnet.att.net/~brixner


#8

trying to solder a small piece to a larger piece.

Leta,

I heat the small thing separately, then heat the solder (I use EZ for
this if I can) into a ball and pick it up with my pick and transfer it to
the small thing.

Then, I heat the big thing. When the big thing is hot enough
I pick up the small thing with my pliers and put it on the big
thing. In a perfect world the solder melts and the join is made
almost immediately. I am getting closer to the perfect world
and never melt the small thing any more.

Remember that the big thing will take much longer to get
hot enough than the small thing did because the whole thing
will get hot. And if you are holding it with a third hand it will
take even longer because the heat will travel up the third hand
meaning you need even more heat to get that big thing hot
enough to solder.

My small things are usually 4mm premade bezel cups and
my big things are pins or rings.

Keep practicing
Kathi Parker, MoonScape Designs
kparkerr001@aol.com


#9

Dear Leta,

be prepared for lots of posts on this. Here’s my 2 cents’ worth…

  1. Make sure both surfaces to be soldered are bright-metal clean. I
    usually do this with a fine file and never emery paper where I am about to
    solder. (I suspect that the emery dust causes burning on the silver
    surface which can lead to pit-holes.)

  2. I often presolder the heavier or larger part using the appropriate
    solder and flux - again cleaning the solder surface to bright metal.

  3. Soldering the smaller part to the larger part is essentially a matter
    of making sure the larger part is heated first so that all the heat does
    not simply run into the smaller part before the solder begins to run.
    Depending on how big the larger part is, you may have to use quite a large
    flame.

By large flame, I do not mean fierce flame. I find that a large, soft
fluffy flame, a “big warm cuddly” flame is best - what we call a
non-oxidising flame. Light the gas first, then introduce the air or the
oxygen so that the yellow just disappears and the flame is a nice soft,
fluffy blue.

The trick is to get the larger part as hot as the smaller part so that
when the solder melts it will pull the smaller part onto the larger part
to form a proper eutectic bond.

Leta, I don’t know what you are soldering here, but there are all sorts of
things that can subtly alter the equation. Such as: Can the little part be
balanced on the larger part, or does it have to be tied on with binding
wire? Does it have to be held in place by tweezers? How little is the
little bit? How big is the big bit? Is the big bit hollow or is it solid?

The more I know the less I know. Hope this helps. You’ll get lots of good
advice, that’s for sure. Regards, Rex from Oz.


#10

Thanks Gail, Im using a Smihlite torch with a fine tip. Should I go
up to a small or medium tip? I was using soft solder,
I melted some solder to the botttom of the small piece first then try to
heat up the bigger piece and suck the small piece to it, with no luck.
Still trying, Leta @Leta


#11

I think I can help you here. First, silver takes much more heat than gold
so have patience. When soldering a heavy piece to a thinner one, you must
concentrate your heat on the heavier one and allow the flame to
occasionally touch the thinner one just a little, if possible, use a 3-rd
hand to hold the pieces together and rest your solder at the joint.
Continue heating and watch the solder ball up & then, when it has melted
and flowed into the joint, remove all heat, remove it from the holder &
allow it to cool on a piece of steel, pickle & polish. Hope this helps.
Steve K.


#12

Hi Leta,
Soldering silver is not easy, but if you follow a few simple rules you
should get the hang of it fairly quickly. You should try to work in fairly
subdued light as it is difficult to see the red heat in silver when it is
approaching melting point. Make sure that you have the correct flux and
the correct type of flame to solder with. The solder you use is also
important. A natural gas or propane flame is ideal preferably with
compressed air. If you are trying to solder a small object onto a large
object use a large soft flame to get your work up to the correct
temperature. Getting the right heat will come with experience. Mix the
flux into a smooth paste and spread it fairly liberally onto your work.
The flux will start to melt around the correct temperature for soldering.
When you reach soldering temperature apply the solder. Allow the heat of
the work to draw the solder from the stick, don’t push it as this will
flood the work. This will mean a lot of extra time needed to clean up the
work. You will need dilute Sulphuric acid or a proprietary cleaning
solution. I think the basic rules are: Use a gentle flame for heating, use
plenty of flux on your work, and feed the solder onto the work when you
get to the correct temperature. Richard Whitehouse UK


#13

Small pieces to larger pieces. Difficult.

I have a large propane burner set up like a gas ring (a gas camp stove
will also do) between two firebricks with mesh on top, and this I use to
heat up large bits that I place on stainless steel mesh over the flame.
THEN when the big piece is hot, the flux looking good and flowing well, I
use my oxy/propane torch to do the last bit of soldering the little bit
on.

Someone mentioned to pre-melt some solder onto the little piece first -
good advice. So that’s 2 stages - 1. melt a bit of solder onto the little
piece. and 2. heat the big piece and WHEN THE TEMP IS RIGHT with p the
flux looking active, bring the little piece ino the hot area. If the temp
is right (evenly hot on both pieces) it will solder. If not hot enough, it
won’t - SO REMOVE THE LITTLE PIECE, add more flux if neccessary, and keep
on heating the big piece. Try again in a few more seconds.

I think we’re all assuming you have a sufficiently hot torch. You may not
have.

And the shapes of the two pieces may make my advice not so useful.

We really need to know more about the shapes, the sizes, the fluz, and the
heat source.

Brian
B r i a n � A d a m J e w e l l e r y E y e w e a r �
@Brian_Adam1 ph/fx +64 9 817 6816 NEW ZEALAND
http://www.adam.co.nz
http://www.adam.co.nz/crit2.htm Recent Work
http://www.adam.co.nz/ruthbaird/ across the bench from me


#14

Hi Leta -

  1. Relax

  2. Make sure your pieces are clean and that the surfaces you want to
    solder together “fit” - smooth against each other without gaps. If you
    can, hold them together up to the light and if you can see light through
    the seam; if so, you need to finish them better so that the surfaces are
    aligned.

  3. Apply the flux to both of your pieces

  4. You can apply solder various ways, but one of the easier is to ball it
    up on a pick and then drop it where you want it, using the heat of the
    torch to place it fairly precicely.

  5. The real key is to heat the big piece, not the little one. Since both
    of the pieces have to be the same temp and the big one will take the
    longest, heat that one to flow temp and the smaller piece will come along
    of its own accord. Don’t move your flame really fast, but slowly and
    evenly over the surface. You can watch the flux and tell where you are in
    the process: first it gets sticky and acts like glue and then as it heats
    up it gets “glassy” - at this point you are pretty close to when your
    solder will flow. Once it starts to flow, use the flame of the torch to
    pull it where you want it, since it will follow the heat.

  6. You didn’t say how big the pieces were, so you just may not have
    enough heat if they are very big. In this case, you may want to think
    about the size of your flame and where you are doing the soldering. Some
    surfaces hold the heat better and reflect it back into the piece you are
    soldering and some do not. You may need more than one torch if you have a
    really big piece…

It does take a little practice, but it will come, eventually - good luck
!!

Laura Wiesler
Towson. Md.
@bgoren1


#15

Curious, if you have your pieces laying on something . . . how do you heat
from “the bottom?” are you using a tri-pod?


#16

Continue heating and watch the solder ball up & then, when it has
melted and flowed into the joint, remove all heat, remove it from the
holder & allow it to cool on a piece of steel,

What is the reason for cooling on steel before putting it in pickle? -
Deb


#17

When I am soldering little things to big things I move the torch
differently dependent on whether I am joining them one on top of the other

  • or - butted up against each other.

If the little thing is butted against the larger you can ‘slurp’ the
little thing in a flash. What works for me here is to keep the flame off
the little thing by moving the flame around the outside edges and only
over the larger piece until the large piece reaches temperature.

If the little piece is on top, I concentrate the flame more on areas of
the larger piece where the little pieces aren’t (hmm… does that make
sense?) In both cases you need to move the torch constantly, slowly and
evenly. If you move the torch too slow or too fast you end up with lots
of fire scale and a bad join. I tell my students to move the torch as
though they were making pudding, nice even circles and figure eight’s,
speeding up, just a little, as the piece (pudding) heats up.

You need to concentrate while doing this, don’t let your mind wander or
you can ‘slurp em’. I ‘slurped’ a couple tonight thinking about the
latest Clinton joke.

Nancy <@nbwidmer>
ICQ # 9472643
Bacliff, Texas Gulf Coast USA


#18

Leta…I doubt if anyone will tell you anything you haven’t already read
but i"ll repeat the basics 1-The work must be absolutely clean. Before you
flux the piece , heat it slightly to burn off the finger oils, and then
handle the piece carefully with tweezers if at all possible 2’ Flux the
piece thoroughly. If you will be applying lots of heat be certain that the
flux you use will not burn away before you are finished soldering. Borax
based fluxes (ie. Handy Flux or even cone Borax that you will grind to a
powder ) are good for this. 3- Apply the heat to the larger piece first.
dont heat the small piece until the larger one is close to solder melting
temperature and then try to bring both pieces up to temperature together.

Most of my own work is holloware (cups, bowls pitchers ) and the problem
you are facing is a common one. Just imagine applying a small decorative
element to a pitcher ! It is routine and just takes practice…but dont
violate the steps I described

Sol K.


#19

Dear Leta

  All of us had a day of beginning...enjoy it..particularly enjoy

the fact you have access to all of these torch wise metal melters,
myself included. I taught jewelry and metalsmithing at the high school
level for a couple of years. All of the things people are typing are
correct. My students had the advantage of having access to my torches.
Many beginners start with a hand held torch available at most hardware
stores…they are very hard to adjust the flame on. and are best used for
soldering copper pipe just before you call a plumber…Plumbers don’t use
’em… the plumber will probably have a prestolite torch…air-acetalene…
you want one…infact you probably want all of the small tips that he doesn’t use.
this torch will produce the soft cudly flame Rex described and have a
good many uses in years to come. The next torch to aquire is called a
little torch… oxy acte or oxy propane much hotter, much cleaner, much
smaller. Inshort my studio contains six torches each of them has something
that it does better than any of the others. there is alsoa burn out oven that
could also be used for soldering.
One of my favorite things is watching the solder flow around
a bezel, I still find it amazing. stay happy brad


#20

Leta-
you say you were using a small tip. A beginners mistake that I used to
make ALL the time. Try using a bigger tip, like a number 4 or a three.
The greater the mass of the silver, the bigger the tip you need to use.
you really have to heat the whole piece, as a lot of our members have
pointed out. The kind of surface you are soldering on makes a difference-
I believe charcoal reflects heat, and magnesia (?) bricks tend to sort of
suck up the heat.

One member said “let cool on a piece of steel” I never heard of that- why?

Anne