By the way....I always pickle after each soldering job, unless I'm
doing something such as multiple prongs on a bearing or some such
thing. This allows me to assess my success (or failure) and to do
any clean up before laying on the next piece. Never had any problem
with multiple pickleings ruining my solder joins. If done right,
they are so small and thin, the pickle can't penetrate or otherwise
effect the joins.
Pickle can even penetrate the microscopic pores from casting. If it
is not all removed which is not so easy in some circumstances. You
will heat the residue on the next soldering. If you use sparax or
other sodium bisulfate based pickel or sulfuric acid pickle it will
break down upon heating and one of the resulting compounds will be
sulfur dioxide. This will bind with the metal and impede solder
flow. Also the metal salts in any kind of pickel will be left on the
surface after the water is gone and these will also impede solder
flow. If you are doing multiple soldering your best bet is to limit
the number of times you pickle. Hot water will remove the flux and
allow you to see what has flowed and what has not. Unless you have
severely overheated the flux it will work fine. If it is overheated
you need to pickle and look at your setup for soldering and find out
why you are overheating the flux.
James Binnion @James_Binnion
James Binnion Metal Arts
In the last line of this note you talk about fire scale when vacuum
investing…how do you use cupronil when vacuum casting. I have had
some bad fire scale on vacuum castings…how and when would you use
"cupronil"
James…thanks for the input. Everything you say is correct.
However, aren’t we splitting hairs here? I mean…are we concerned
with nano level contamination. After 35 years of soldering all kinds
of jobs, castings, etc, etc., I have (after attaining a level of
proficiency as we all must do) never experienced a failed join or had
any problem with solder flow. Your point about using hot water is
well taken and, I have used it and it works. However, water simply
does not always clean the surfaces sufficiently if one is doing
’in-between’ clean ups.
While this may work well for experienced jewelers, i.e. those who
know torch control and do not overheat, the newer guys and dolls
rarely have such control, and tend to routinely overheat Also, new
jewelers tend not to give enough attention to intermediate clean up.
In many years of teaching fabrication, I find it essential that
students completely clean their partially completed projects after
each phase. This is best accomplished by pickeling which gets them
into a routine as well. To wit, a routine that usually lasts a
lifetime. I find regular pickeling easy and worthwhile.
Guess one might say…to each his own!
Cheers from Don at The Charles Belle Studio in SOFL where simple
elegance IS fine jewelry!
In the last line of this note you talk about fire scale when
vacuum investing...how do you use cupronil when vacuum casting. I
have had some bad fire scale on vacuum castings...how and when
would you use "cupronil"
Sorry if I misled you into believing I use Cupronil to prevent fire
scale when vacuum casting. The technique of preventing fire scale on
a casting is a different process whick is very simple.
Thanks to Orchid and the excellent work of Hanuman the process of
preventing fire scale is listed in the “Tips From the Jewelers
Bench.”
The simple method of preventing fire scale when casting is described
in:
A more advanced way or preventing fire scale on a casting is
described in:
Contact me if you have anymore questions.
Lee Epperson
I pickle after each and every operation that involves heat. Solder,
anneal. I even pickle platinum even though there’s no reason - no
flux, often. I also rinse thoroughly, especially silver. I like to
work clean…
If you use sparax or other sodium bisulfate based pickel or
sulfuric acid pickle it will break down upon heating and one of the
resulting compounds will be sulfur dioxide. This will bind with the
metal and impede solder flow. Also the metal salts in any kind of
pickel will be left on the surface after the water is gone and
these will also impede solder flow.
I’ve found hot water and alum effective for removing fluxes, even
Prips. With thorough rinsing, subsequent solderings have not usually
been a problem. Have I just been lucky?
whether there are gaps in the bezel-to-backing seam with the
built-up flux all over it.
The flux glass makes examination very difficult. If you have
problems finding gaps on a cleaned piece, hold your piece at the
lower edge of the shade of a bright lamp, letting the light hit the
base of the bezel. As you turn the piece, keep the bezel very near
the shade and examine the interior of the bezeled area for light
leaking under the bezel. I usually mark any gaps within the bezel
area using a sharp scribe so I can locate it without the light when
I’m ready to re-solder.
If you have problems finding gaps on a cleaned piece, hold your
piece at the lower edge of the shade of a bright lamp, letting the
light hit the base of the bezel.
A tiny improvement on this is to hold one of those teensy LED lights
inside the bezel-- preferably a red or blue one (the kind you can
hang on your key chain). They are very bright, so there can be no
doubt when that red light peeks through any gap, however tiny. My
students cringe when I reach for the “light test”…
Noel
Note From Ganoksin Staff:
Looking for a led work light for your jewelry projects? We recommend:
A tiny improvement on this is to hold one of those teensy LED
lights inside the bezel-- preferably a red or blue one (the kind
you can hang on your key chain).
Oh! That’s very clever. Why red or blue? Easier to see?
I usually hold it up to an overhead light, but this would make it
easier for you and the student to see it at the same time.
“The tiny LED light as from a key chain light” what a novel idea. I
will take one to my next class…the students will all be excited to
see how much easier detections can be. There are so many clever ideas
shared on this Orchid forum. Hats off to you all!
Yes, there’s no doubt at all when red light shows through a gap.
Can’t be just a reflection, etc, can’t miss it because you didn’t
hold it up just right to the ceiling light.
I bought a set of three bright LED’s from American Science & Surplus
that are supposed to be “rockets” that are “rings” for the 4th of
July-- they have a little elastic band for the finger, are vaguely
rocket-shaped, and have an LED with an on-off switch, one each red,
white and blue, for a couple of bucks. I keep the red one in my tool
box I take to class when I teach (I don’t generally need this trick
at my own bench).
Found very interesting your point and perhaps would like to try
those leds, I visited the American Scinece & Surplus but could not
find exactly what you found, just many kind of leds. Please could
you let me know what should I look for as to buy them.
I visited the American Scinece & Surplus but could not find exactly
what you found, just many kind of leds. Please could you let me
know what should I look for as to buy them.
See, it really is Surplus. What she bought may not be available
anymore, you may have to buy new.
At AS & S, if you see something you like, buy it, buy two. You’ll
think of a use later.
I visited the American Scinece & Surplus but could not find
exactly what you found
As I mentioned, I bought those around the 4th of July… It is a
surplus place, things come and go. The point is, there are cheap
little LED’s, mostly attached to key rings, that can easilt be
inserted into a bezel. Even drug store checkout counters often have
them.
Reading about Firescoff reminds me about that %^%$# fire scale and
its prevention. Fire scale has been the scourges of all who cast or
solder sterling silver. There are ways to prevent it both during
soldering and casting…
Since 1975 when I first started making sterling silver jewelry I
have been amazed at how many jewelers and instructors do not know
what fire scale is.
I remember I had an on going discussion with a very well-known
casting expert about fire scale. He claimed he never got fire scale
on his cast items. His solution was to hold a reducing torch on the
sprue button for a while after pouring the metal. I claimed that that
would not prevent fire scale. I didn’t realize he tumbled all his
items. One time when I was in his studio our discussion came up
again. I told him to take one of his cast bracelets and hit it on
the buffing wheel. He walked over to the buffer and in a few seconds
a long string of cuss words came from him. For the first time he
realized he got fire scale. The tumbling just hid it.
All you who cast vacuum cast sterling silver should check out my
simple process that prevents it from forming during the casting
process. Check out the two papers I wrote on the process. The process
really works and it is very simple…
All jewelry supply houses sell various means of preventing fire
scale when soldering. Curponil is the oldest commercial product on
the marketl. They were the first Company to use a spray to place the
solution on the metal. It is the product many others have tried to
copy.
Some of the agents also work as fluxes during soldering. If you are
going to solder sterling silver you should definitely use one of the
products that prevent fire scale. You will definitely prevent fire
scale and reduce lots of polishing time and will end up with better
looking jewelry.
I strongly recommend you pre-polish the silver areas that will be
difficult to polish once the construction is completed. Always coat
all surface of the silver where you do not want fire scale to form.
Just a side note: I have written many papers on wax carving,
engraving and turning of waxes All the papers are posted on the
Orchid site.
Contact me if you have any questions about casting, soldering or wax
work.
Thanks for the Orchid site. A BIG THANK YOU to Hanuman and
Ton!!! The members are so generous in sharing that
helps us all. Many members have written how to articles that are
stored on the site. The site store all the comments that have been
made over the years. That library provides an excellent source of
.
I am a perhaps the oldest and most staunch supporter of Cupronil. I
have used it without fail since the 70’s. It’s made by 4S labs and
is far more reasonably priced than Firescoff. and in reading the
ingrdients in Firescoff where, exactly, is the ceramic?. I had
problems with their MSDS initially and they did change it to be more
’realistic’ as to the hazards involved with the product. but their
price has continually risen, while Cupronil has remained the same, I
think, since the 70’s. It is often imitated - anyone can copy a
shade of blue, or worse, buy a quantity of a product and relabel it
without telling the manufacturer their intentions, (nor I suppose
giving them a due percentage of “royalties” if using the original
manufacturer’s MSDS).
My bottom line is no prepared product works as well or applies as
evenly and consistently as Cupronil. I recommend it wholeheartedly
to any aspiring metalsmith over any other on the market. rer
In Charles L-B’s article Some Thoughts on Fire Scale,
he mentions a solution of boric acid and borax. He says to mark one
side of a container with a mark at the half point and the other side
with marks at third points. He says to fill to the half point with
boric acid, then to the top third point with borax. As I visualize
this, it’s really saying to use equal parts of the two chemicals.
(Filling to the half point = 1.5 thirds. Filling from there to the
top third line is also 1.5 thirds.) So how am I seeing this
incorrectly?
In Charles L-B's article Some Thoughts on Fire Scale,
http://www.ganoksin.com/borisat/nenam/firescal.htm
he mentions a solution of boric acid and borax. He says to mark
one side of a container with a mark at the half point and the other
side with marks at third points. He says to fill to the half point
with boric acid, then to the top third point with borax. As I
visualize this, it's really saying to use equal parts of the two
chemicals.
(Filling to the half point = 1.5 thirds. Filling from there to the
top third line is also 1.5 thirds.) So how am I seeing this
incorrectly?
He undoubtedly meant fill with borax to the two-thirds mark, else
there’d be no room in the container for alcohol. When you mark a
container in thirds you make a line at the 1/3 point and at the 2/3
point, and as the top of the container is itself the 3/3 point one
doesn’t make a line there. So the “top third mark” is not the top of
the container but the uppermost line demarking thirds, i. e., the
2/3 mark; not the “top third” mark but the top “third mark” if you
will.
By volume:
3 parts boric acid
1 part borax
2 parts alcohol