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Pickle effecting solder joints


#1

Hello everyone,

Has anyone had a problem with leaving a piece of jewelry in pickle
for an extended amount of time, and having the solder seam(s) weaken
and snap because of it. I came across this problem when I was living
in Brasil, where I would leave a piece in the pickle over night,
just plain forgot about it as the time reached early morning hours,
and the next day the solder seams would snap and open. At that time
I thought it was just the kind of acid we used there was too
powerful, being that the studio I was working in was very rustic and
with limited access to the proper chemicals.

Just recently I left a piece in the pickle over night and the same
thing happen. I mean, I was totally confident with my solder seam,
not to say I have not been mistaken before, two tabs opposite each
other for settingnthe stone and the following day they both snapped
off as if they were stuck there with crazy glue. Like I said, I felt
very good about the solder seam. After the first time this happened,
I re soldered the two pieces back on…left it in the pickle for
about 4+ hours, forgot to take it out again, and they snapped off as
well.

Now that you have the story of my situation, does anyone know if
pickle can effect the solder seam in this way? Breaking down the
connection in such a way that it will snap that easily. Any info on
this will be very helpful.

Cheers
Steven Brownlee


#2

What do you use as pickle? I use 8% sulphuric acid but I know others
who use hot 5% sulphuric. If you leave silver in it for too long you
get a bit of etching where the copper/zinc component of the solder
dissolves but I have never seen anything other than surface etching.
I would suppose that if you use something else or leave you piece in
for about a week then you will dissolve more of the base metals in
the solder and create a sponge which will be brittle/have low
tensile strength. I have done this on purpose with gold/copper and
platinum/copper alloys to create porous membranes for catalysis using
dilute nitric acid. can be done with other etchants but why
complicate things.

Nick


#3
Has anyone had a problem with leaving a piece of jewelry in pickle
for an extended amount of time, and having the solder seam(s)
weaken and snap because of it. 

Pickle cannot affect solder joint in any way. However your
experience is true. You simply reaching the wrong conclusion. If
joint
is not well prepared, or heat is misapplied, or dozens of other
reasons; flux flows into the joint and preclude solder to enter. Such
joints looks ok. If well fitted, joint can even survive a pickle, but
invariably fails later. If fitting is so so, the pickle will dissolve
the flux and joint falls apart.

Leonid Surpin
www.studioarete.com


#4
does anyone know if pickle can effect the solder seam in this way?
Breaking down the connection in such a way that it will snap that
easily. 

Yes, it can. Our normal pickles (sodium bisulphate) are salts of
sulphuric acid (which used to be used by itself for pickling). This
doesn’t much dissolve silver, but is effective on the various oxides
we use, so it’s a good pickle. It’s not highly active at dissolving
the other metals in solder, but it will, slowly, do so to an extent.
And even silver itself is slightly attacked if the acid is hot.
Silver soldered items left in the pickle for long times will have
some of the copper and zinc leached out of the solder. That makes it
porous and less strong than it should be, so it then fails. This
doesn’t happen with normal short pickling times, so just don’t leave
items soaking in the pickle longer than you need to. Even plain
sterling silver, left in the pickle for a long time, will come out
looking a bit dingy, despite only having a little available copper
for the acid to attack…

Peter Rowe


#5

Yes, this happens. Don’t leave things in the pickle pot overnight.
Maybe a reminder note on the studio exit door would help?

M’lou


#6

Hey Steven, pickle will destroy your solder seams if left overnight.
I’m surprised you don’t mention any affect on the silvers’ surface
as well. Do you have your pickle heated or cold? If you’re heating
your pickle then nothing should take longer than 20 minutes. Cold,
I’m not so sure, but I’ve never had the guts to leave anything in
pickle overnight, even when I’ve used it cold. I suggest you heat
your pickle (you can buy an incubator, or just use an old pan on the
lowest heat, but make sure it is covered!) You’ll probably lessen
the chance of you leaving anything in it overnight as everything will
take less time.

Regards
Laura Honeker
London


#7
Pickle cannot affect solder joint in any way. 

Leonid, that is indeed true for gold solders. It is not, however,
true for all silver solders, especially the medium and easy grades.
Those contain enough copper and zinc that hot pickle will indeed
deplete the solder joint of some of those alloying metals. It can
happen with silver solders because silver is very slightly attacked
by hot sulphuric acid, so the pickle is able to slightly penetrate
into the surface of the solder. It won’t affect more than the
surface finish of sterling or fine silver itself, but a piece left in
hot pickle for a few days will indeed look somewhat dingy and
affected. And a solder joint can have some of it’s copper and zinc
leached out. Of course, you are also correct that the quality of the
solder joint is also a big factor. If the seam is well fitted, and
the joint is soldered with the correct amount of solder and not
more, and is properly flowed, etc. etc, then the degree to which
pickle will be able to make a difference with the joint will be
minimized, as you suggest. But the pickle does indeed, given enough
time to work, actually attack the lower melting silver solders.

Peter Rowe


#8

Anything to excess is usually bad. But in general pickle won’t eat
solder, even a hot 10% sulphuric.

The only problem I ever had was mixing up the pickle and nitric etch
(labels are a really good idea :slight_smile: and leaving it over night, two
mistakes in a row. It took a day and the studio was cleaned top to
bottom before I realised that the missing bracelet was now a life
time supply of silver nitrate.

I try to avoid mistakes, but still am capable of really professional
grade ones.

jeffD
Demand Designs
Analog/Digital Modelling & Goldsmithing
http://www.gmavt.net/~jdemand


#9

Yes it’s happened to me. Often. Overnight in pickle certainly can
weaken a seam such that a bezel for example will readily pull free.
It is indeed the acid that compromises the seam. I’ve looked at such
tears under the microscope. All along the seam there is a grey
sponginess of uniform texture. This uniformity indicates that the
whole joint is equally affected, hence by acid, since one would
expect indications of flux and dirt residues on to be localized. If,
however according to Mr Surpin’s magisterial diagnosis, the culprits
are invisible flux residue and invisible dirt, then we get into the
domain of metaphysics, not metallurgy and this is unfamiliar
territory to me.

Cheers all
Hans Durstling
Parrsboro Nova Scotia for the nonce


#10
Leonid, that is indeed true for gold solders. It is not, however,
true for all silver solders, especially the medium and easy
grades. Those contain enough copper and zinc that hot pickle will
indeed deplete the solder joint of some of those alloying metals. 

But it all stems from bad soldering. If solder is over-heated and
zinc is burned out, it created pathways for the pickle to enter and
start working on copper. The problem is not the pickle but the
soldering. Such joints are crap anyway and will fail in a short time.

Leonid Surpin
www.studioarete.com


#11
Pickle cannot affect solder joint in any way. 

you are wrong on this one. Maybe your skills and experiences dictate
that you would never leave a piece in pickle too long but for
novices:

Sorry to say but any pickle- from sulfuric acid, to Nitric acid,
sodium bisulphate, sodium bisufite, hydrogen peroxide, citric acid-
what whatever pickle one chooses to use can, and does attack the zinc
in a join if the piece is left in the solution for more than the
recommended amount of time for a given metal - that is overnight. So
novices, NEVER leave a piece in pickle overnight - or even a few
hours if you can avoid it,. In particular when a join has been
reheated and the melting point raised in the process the zinc in the
solder is adversely affected (sheet, paste or wire) the join is
etched and can pit, and will fail eventually. No amount of filing
will level the problem if the solder was applied too thickly as it
permeates into the crystalline structure.

You will have to remove the affected solder (cutting or sawing it
out is the most direct means) and start again, with clean metal,
reflux the whole thing and heat both parts simultaneously applying
solder by whichever method you are comfortable with to the join at
the point of flow. No matter what anyone tells you, it is not a good
practice to get in the habit of- leaving a piece in pickle not only
makes a super saturated solution of copper ions( that is what turns
pickle solutions blue) that will plate copper onto anything as soon
as any steel is introduced (leaving a rosy coloured coating on the
metals- any metal and particularly alloys, brass, etc. that contain
copper) and the circle of steps to set up an electrolytic action is
completed.

rer


#12
you are wrong on this one. Maybe your skills and experiences
dictate that you would never leave a piece in pickle too long but
for novices 

Archeologists find jewellery buried in the ground ( very corrosive
environment ) for thousands of years and most of it on one piece.
That
should convince anybody that if joints fails in the pickle, it is not
the pickle but the joint. Pickle in this case is a quality assurance
step. I recommend going a step further and boil out jewellery in acid
bath as the last step of soldering process.

Leonid Surpin
www.studioarete.com


#13

Thank you for all your great input. This sets me more at ease. Yes
the joint was soldered correctly, and with only the appropriate
amount of solder. It happen to be the last solder seam, and not to
disturb anything else, I used easy solder.

I just have one more question…What is that pickle substitute?
Isn’t it a pool cleaning solution? Will that effect the solder seam
also? I guess thats more than one question…I tried to search the
Archives and was unable to pull anything up. Is there a tutorial for
Ganoksin that will explain how to search for past threads?

Thanks,
Steven Brownlee


#14
I just have one more question....What is that pickle substitute?
Isn't it a pool cleaning solution? Will that effect the solder
seam also? 

Depends on what you mean by pickle substitute. The commercially sold
pickles, such as Sparex, are sodium bisulphate. Sparex happens to be
a rather impure form, to the annoyance of myself and I think, more
than a few others, since the impurity, some sort of gunky brown wax,
makes a mess of the pickle pot. Plus they don’t exactly sell the
stuff cheap. So many of us don’t buy the commercial pickle, but
rather a pool chemical (not a cleaner, though, but one to adjust the
ph of the pool water) which is often called ph-down, or spa-down, or
some such. all of these are also sodium bisulphate, with the
difference from sparex being generally a lower price, and a clean
pickle pot without the brown junk. Being the same chemical, it will
have the same problems.

However, you might wish to try another alternative pickle, that
being citric acid. You can get it as a food grade or lab grade or
industrial chemical depending on where you buy it. It works more
slowly, and less aggressively than sodium bisulphate, but does remove
mild oxidation and flux from soldering, and it has the advantage of
being safer to use than sodium bisulphate. I do not know if it’s
totally immune to causing the problems with solder joints over long
immersion, but would suspect it to do this less, if at all. But you
have to leave you work in the pickle longer with citric acid, so then
it might be easier to forget to take it out.

For me, the simple fix is simply not to leave things in the pickle
for very long. My pickle pot is a small crock pot, used on the low
heat setting, and I’m always careful to turn it off at the end of a
work day or session where it will be needed. And when turning it off,
I always make sure I’ve not forgotten something in there during the
day. So excessively prolonged immersion simply doesn’t happen with
that routine.

Peter


#15
Archeologists find jewellery buried in the ground ( very corrosive
environment ) for thousands of years and most of it on one piece. 

Gold yes. Silver jewelry from even Roman times is rare, and from
earlier than that, exceedingly rare, in part because silver jewelry
and items themselves, not to mention joints, don’t survive all that
well buried for very long periods of time. And also because silver
itself was often rarer than gold, at least in egyption times, and
when found, often was found as and used as, a mix of silver and gold,
which improves durability over time. And though being buried in the
ground is indeed corrosive, it’s differently so, being more a salt
environment than a highly acid one. The effects are different. As
well, it should be pointed out that silver solders, as we use them
and formulate them today, don’t go back much beyond the middle ages
or so, and even a couple hundred years ago, soldering was always done
over a hearth (furnace). Different techniques, different solders, so
you cannot really compare current observations of the failings of
current methods, with the state of ancient works made by different
means.

That should convince anybody that if joints fails in the pickle, it
is not the pickle but the joint. 

As I said, since your observation doesn’t compare similar items and
similar conditions, such a conclusion isn’t totally valid. I do agree
with you that pickle by itself is not the sole culprit should pickle
weaken a joint. The techique itself, as well as the grade of solder,
is also involved. But I have seen joints that failed after long
immersion in pickle, while identical joints, saved that immersion,
stood up well. The pickle may not be the only cause, but it certainly
is capable of damaging solder in some cases.

I recommend going a step further and boil out jewellery in acid
bath as the last step of soldering process. 

That, Leonid, may be overkill with silver work. With gold, and
certainly with platinum, it can be useful. With platinum, some
advocate it BEFORE soldering to eliminate any potential traces of
iron, etc. But please keep in mind, yet again, that this thread is
about silver and silver solder. Sodium bisulphate pickle is already
corrosive enough. Boiling sulphuric acid will actually slightly
attack sterling silver, slowly etching/dissolving the surface. Is
that actually what you want? And I’m assuming you don’t mean a nitric
acid boil, since that totally dissolves your item quickly, and
Hydrochloric acid will leave a somewhat cruddy surface film. Is that
what you want? And boiling strong acids may not be a step you really
want to recommend, especially for beginners who may not have a good
fume hood to do it under…

Peter Rowe


#16
Archeologists find jewellery buried in the ground ( very corrosive
environment ) for thousands of years and most of it on one piece.

True. But you can find most of these pieces with their pearls and
stones still intact. I would have thought that if the environment
had been so destructive then a pearl or a soft emerald would suffer
much more than the metal.

Pickle is acid, we use it to strip off the layer of dirt and flux and
whatever else is left over once we’ve soldered something. It is
corrosive and therefor will destroy most things one way or another if
they are left in for too long. I have put many a bad solder seam into
the pickle and they’ve come out fine. I once left a good solder seam
in my pickle overnight and the whole piece was destroyed and I had to
start again. However, I didn’t have to learn from my experience as it
was kind of obvious what would happen.


#17
I just have one more question....What is that pickle substitute?
Isn't it a pool cleaning solution? Will that effect the solder
seam also? 

Yes, it’s Spa Down or Ph Down. It’s the same stuff as Sparex #2,
only more pure, as has been covered on Orchid a lot. (Just search on
the “pickle poop thread.”)

It’s the same, so it was affect your metal in the same way as
Sparex.

Elaine
http://www.CreativeTextureTools.com


#18

I feel pickle left on a piece (IE the inside of a soldered hollow
form, a bead for instance) will eat at the solder. after the last
pickle I will put in a baking soda bath to neutralize acid. I put it
in a film canister in the ultrasonic if it has only a small opening

Candy.


#19

Ok Once more, Most of the jewelry I or the Dept.'s Of Archaeology at
Tulane University, University of New Orleans, and Royal College in
London found on digs was 24 karat gold based…it doesn’t fail and had
no solder but was fused or eutectically joined… In Central and South
Americas and in North America mainly silver, and silver and a little
gold in the southwest. US digs. Different context, different
discussion- we are talking practical modern jewelry making here
with modern zinc containing solders.

Also if you knew soils- not all are corrosive. In fact many are
preservative like clay soils and non-acidic stone based tropical
soils, as well as underwater environs were pressure and absence of
light and acid air prevents corrosion- again, context…

As far as archaeologists finding jewelry in the ground- most is
not in one piece unless it was one piece construction-particularly
regarding bead-work, and in African, Indian, Turk- Ottoman, Moorish,
and and other digs I have direct experience with that was the case
always.

I know solder though and in this context it is in fact pitted,
attacked, etc. by leaving in pickle overnight- refer to Tim
MCcreight’s Complete Metalsmioth, Oppi Untracht’s Metal Techniques
for Craftsmen and a host of other published authors if you care to
continue to recommend or imply that it is a safe practice to
recommend to novices to leave soldered metal in pickle- it’s just
plain crazy.

note to novices: leaving jewelry that has zinc containing solder in
pickle overnight is a bad practice or habit to get into- after being
heated two or more times soldering/brazing burns the zinc off
leaving the metal mass in the join subject to extreme pitting (in
particular silver and low karat golds)…no questions, it is a fact of
metallurgy.


#20

That should convince anybody that if joints fails in the pickle, it
is not the pickle but the joint.

Leonid, [] I will run a test with pictures of how acids can destroy a
solder joint, irrespective of soldering techniques. On my ganoksin
blog, if you wish Your call.

Hans
http://www.meevis.com
http://hansmeevis.blogspot.com