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Solder won't flow


#1

Greetings to the kind folk of Orchid,

Feeling frustrated and am reaching out for suggestions.

A student has been working many months on this ring:



#2

Lois-A little more info please. What karat? What type of solder?
Hard, medium, easy? Plumb solder or repair solder? Torch and gas ?
Flux brand? Which seams are the problem? How is it being held while
soldering. What kind of surface is it being soldered on? All of these
are important factors needed before giving a good answer.

Jo Haemer
timothywgreen.com


#3

Solder flows or doesn’t for only a few reasons it seems to me.
Cleanliness is the biggy usually. Is the surface contaminated with
oil from dinner tips. Is the fit good? Is there enough heat or too
much heat. Is the solder the correct solder for the flux?

Don.


#4

When solder won’t flow, it is always some combination of the 4 Fs:

-flux
-flame
-fit
-fastidiousness (cleanliness, but that doesn’t start with f, y’see)

You need good clean, well-fitting surfaces, appropriate flux that
hasn’t been burned away from long heating, and enough heat (applied
to the body of the piece, not the extremities). It is almost never a
problem with the actual solder.

These days, with more and more people using handheld butane torches,
it is often hard to get enough heat and get it where you want it.

Noel


#5

HI Lois,

Soldering 101 - If solder won’t flow, it’s one or more of these -
the joint is dirty, it doesn’t fit tightly enough, and/or it’s not
getting hot enough.

Dirty might mean physically dirty in that it has grease or wax or
some other foreign material in or on the joint or the solder itself.
It can also be fire-scale from previous attempts at getting it to
flow. It doesn’t have to be visible dirt, a fingerprint can be enough
to interfere with the flowing of solder. Contamination of the fuel
that the torch is burning has been known to cause problems too, but
that’s pretty rare and very unlikely to be the cause of your
student’s problem. Junk in your flux can cause issues too.

Solder won’t jump a gap. If the pieces aren’t fitted tightly
together, the solder will usually jump to one side or the other
rather than fill the joint. It’s usually the lighter piece that the
solder flows to as it generally heats up more quickly, and solder
will usually flow towards the heat source. Solder can sometimes be
pushed across a gap with a solder pick initiating flow while passing
through the slushy state, but that can be kind of tricky and really
isn’t the right way to do it. Usually.

Not only does the solder joint have to be clean and tight, it must
be heated to the right temperature and the heat must be high enough
on both pieces to be joined. When one part is much heavier than the
other and if the joint is tight, gapless and clean, it is usually
sufficient to heat the heavier piece up to temperature and allow the
heat to conduct through to the lighter piece. This helps to minimize
the risk of melting the light piece while waiting for the bigger
piece to come up to temp. It’s probably important to note that solder
will flow towards the heat so whenever possible, put the solder on
one side of the joint and heat it from the other side to pull the
solder through the joint.

I hesitate to speculate on the ring in the photos because I can’t
really tell where the problems are, and you didn’t say specifically.

In any case, whenever you’re troubleshooting soldering problems, go
back to the basics. It’s always one or more of these three that’s the
culprit.

Dave Phelps


#6

Dear Jo,

Thank you for your help.

the whole ring is 22 karat gold. We started with 22KH solder and are
now using 18KS yellow gold solder.

the heat is acetylene-atmospheric with Smith torch #0 the flux is
Batterns. The whole ring dipped into flux and then heated then the
18KS solder fluxed and set inside the bezel. We have also been using
ochre to protect previous soldered areas (I am thinking maybe there
is some kind of invisible build up of flux and ochre).

the problem seam is the second bezel joining the shank. The shank is
thick, 0.032 inches.

I tried soldering on a charcoal block and a tripod with screen. we
can’t use binding wire to hold the bezel to the shank at this point
because it will leave marks. The fit of the bezel on top of the
shank is perfect, we held it in place with flux, gravity and
balance.

Any all all thoughts are appreciated.
Warm regards,
Lois


#7

Is the solder the correct solder for the flux?


#8

Thickness of the metal is a real and often over looked issue but it
is again a function of the heat. Too much or too little.


#9

appropriate flux that hasn’t been burned away from long heating Dear
Noel, What flux would you suggests for long heating?

Kind regards,
Lois


#10

Greetings,

Thank you for responding and trying to help. The piece is all 22
karat gold. The solder used to try to connect the bezel is 18KS
(which was not milled thinner). The heat is an acetylene atmospheric
torch with Smith tip #0.

Whole ring warmed, dipped in Battered flux, heated again, ochred in
spots, heated, cooled and then fluxed solder chips were placed
inside the bezel.

It was hard to direct the heat under the bezel (any tips).

Maybe it wasn’t clean enough. Any tips on how to make sure the metal
is clean? Should we use pumice powder? Should I have milled the
solder thinner?

Thank you.
Best regards,
Lois


#11

Most other post have said what I am about to say, but there is
strength of evidence in numbers.

  1. Make sure that your soldering area is clean and free of anything
    that will contaminate it, especially lead solder.

  2. Make sure that the pieces to be soldered are clean. I usually
    heat to hot and pickle just to make sure.

  3. Remove any fire scale from previous attempts to solder.

  4. The joint has to be tight. File and the then look at the pieces
    together backlighted by a bright light. You can see any imperfections
    by the way that the light passes thru the joint. Go back and fix
    them.

  5. Flux with a flux that you know well. I used Batterns for years,
    but went to borax and then Handy Flux about ten years ago. It works
    very well for me. If there is any glassy residue after I solder, then
    the piece spends some time in a water bath while I get a beverage
    appropriate to the time of day. The residue is dissolved in the water
    or easy to remove prior to finishing.

  6. Heat the joint evenly, especially for silver. Stay way from the
    joint for a bit if you can. Sometimes this is impossible. You are
    trying to get the entire joint area up to the same temperature at the
    same time. If the solder is one side of the joint, heat from the
    other side as the solder moves towards the heat.

  7. Try to learn to remove the heat slowly from the joint so that the
    solder cools as slowly as possible. This allows gases to escape while
    the solder solidifies and is less likely to leave pits in the solder.
    This is hard to learn and I am still learning it. The reason for it
    still eludes me and possibly someone reading this post might
    enlighten me as to if and why this is important.

  8. Quench after the piece no longer glows in dim light.

  9. I leave it in the pickle for a while and then soak in rinse water
    (another chance for an appropriate beverage).

  10. Dry and look it over. I find that inspecting under the new LED
    lights now on the market helps to show imperfections that you would
    otherwise miss. This is especially true of polishing as firescale
    shows up well under LEDs. I cringe at what I used to sell prior to
    being able to inspect my work under LEDs.

I find that, if I have been away from the bench for a while, I need
to relearn to solder. Don’t try your most complicated soldering task
if you have been away for a couple weeks, relearn and then try it.
That’s about is. Good luck. Rob


#12

Hi Lois,

The first mistake the student made was to make the ring in the
incorrect sequence.

The bezels are soldered on first.

Then the twist wire.

Then the outer bands.

I have a full tutorial (you’ll pay) on how to make several
variations of this ring correctly.

http://www.ganoksin.com/gnkurl/ep827g

Also, the solder should be first soldered onto the bezel edge and
then partially filed off so that only a thin layer of solder
remains.

The bezel is then fitted on the ring using binding wire to hold it
into place.

The ring is fluxed and heated with a reducing flame until the solder
flows.

This method, while a bit more time consuming, will make a neat
solder joint with no excess solder.

For a very short video where I describe this technique, (for a
different tutorial), check out

Another method is to pierce out the ring and then fit the bezels
into the shank and solder them from the inside also before the twist
wire is fitted.

Construction sequence is most important and the sequence that the
student’s ring was made in, makes the finishing off of the center
band much more difficult.

(no disrespect intended)

Also, It is very important to have the bezels finished off to just
before the rouge polishing stage before they are soldered onto the
shank.

This cuts the final finishing time down a lot.

Kind regards,
Hans Meevis
meevis.com


#13

Lois, it’s not so much about choosing a flux that is good for long
heating, it is about heating fast enough that the solder flows before
oxides accumulate (not really an issue on high-karat gold) or flux is
exhausted.

The 22k has a high melting point, so as long as you’re heating from
inside the ring, you can heat it aggressively without fear.

My guess, from your additional info, is that the ochre is the
problem.

There shouldn’t be any need for it, and it has a way of getting
where you don’t want it.

If you have tried repeatedly to solder, the previous joints have
probably had ample opportunity to interlace (I’m forgetting the
technical term) and are unlikely to let go.

When the solder goddess is being pissy with me on any given day, I
like to try a belt-and-suspenders approach; I use borax and alcohol,
burn the alcohol off, then add Battern, Prip’s, Cupronil or Handiflux
to the joint, as the mood moves me, and try again. Used this way, I
find Handiflux can be a big help-- otherwise, I don’t have much use
for it.

Make sure all the orchre has been cleaned off and go in hot and
fast, from below. If all else fails, use a lower-temp solder, but
only as a last resort.

Noel


#14
we can't use binding wire to hold the bezel to the shank at this
point because it will leave marks. 

Knew Concepts sells titanium soldering clamps that can be bent and
filed in ways to solve a lot of holding problems.

http://www.ganoksin.com/gnkurl/ep827h

They show some examples. Click on the link at the bottom left of the
page:

Titanium soldering clamps in use

Worth knowing about, having on hand.

Neil A.


#15

Your issue may - just conceivably - lie with the solder itself,
particularly if you’re not accustomed to it. I’m presently working on
an 18 K piece for which I acquired a tab of 18K medium yellow solder.
I had not worked with 18 K solder before. The experience was a bit
unnerving. It melts, yes, and flow, yes - but at a temperature that
is desperately close to the melting temperature of the metal itself.
Until then it just sits there, red hot, with everything around it red
hot, and does nothing.

Cheers
Hans Durstling
Moncton, Canada


#16

Dear Hans,

Thank you for sharing that high karat golds are tricky. Working with 22
karat gold is my passion but it can certainly be challenging.

Kind regards, Lois

D21FD1E-D79F-4FAF-A838-1493446CB6C8
8

Dear Hans, Thank you for sharing that high karat golds are tricky.
Working with 22 karat gold is my passion but it can certainly be
challenging. Kind regards, LoisSent from my iPhone
D21FD1E-D79F-4FAF-A838-1493446CB6C8–


#17

Thank you for all the great ideas. Much experimenting ahead for me.
Orchid is a wonderful place to be. To be able to reach out and
actually get help is priceless.

Thank you.

Warm regards,
Lois


#18

Dear Neil,

http://www.ganoksin.com/gnkurl/ep827h 

These titanium soldering clamps look like a much needed addition to
my bench. My order has been placed. Thank you so much.

Kind regards,
Lois


#19

Dear Hans,

Thank you for the insight about sequence. I purchased the tutorial
and will experiment. Your work is beautiful.

So wonderful to be part of such a caring, helpful community. Kind
regards, Lois


#20

The solder goddess

Dear Noel,

Your input has been very helpful. I am being to see the error of my
ways.

Yes, the Solder Goddess commands respect. No getting around it.

Going to save your contributions and refer back when I am stuck.

Thank you so much.

Kind regards,
Lois