How useful is reticulation?

Hello,

What can I do? I have reticulated pieces of sterling silver 20x25x2
mm on coal with a propane torch, both with and without stop-ox, but I
run into something that looks as heavy firestain which is almost
impossible to cover by depletion gilding. In some case, when
prolonging the annealing time for a couple of minutes, the firestain
increases!

Is it possible to prevent or get rid of these spots without
expensive equipment and how can I be sure that the spots doesn’t pop
up after a year or two? Is this a technique only suitable for
industrial manufacturing or casting?

Eva Nedergard
atelje54.se

but I run into something that looks as heavy firestain which is
almost impossible to cover by depletion gilding 

Eva, firestain is a virtually unavoidable aspect to reticulation.
Here’s why: We prepare the metal be repeatedly annealing and
pickling, right? What that does is not, as it’s often incorrectly
described, “bring up the fine silver”. The silver is already there,
and hasn’t come up. What happens is that we’ve oxidized the copper
that’s in the surface layers of the silver. then pickling removes the
copper oxide. Copper oxide is also a larger molecule, so it’s not
“comfortable” simply in the original position in the metal. When you
anneal, as with almost anything in the alloy, molecules diffuse, or
move around some. In the case of the copper oxide, it too diffuses
around upon heating, but unlike pure metals in the alloy, if it
happens to reach the surface, then it stays there. All in all, the
result is to deplete the surface layers of copper. Doing this
requires that oxygen is present during the heating, in order to
oxidize the copper at and near the surface, or which may diffuse up
to the surface upon heating. But oxygen is also capable of diffusing
INTO the silver. It doesn’t just wait at the surface. To a degree,
this aids in oxidizing and removing the copper in the surface, which
is what needs to happen to prepare the metal for reticulation. But
there is a depth beyond which the copper is not removed, but where
oxygen has reached, so there remains copper oxide. In preparation of
reticulation metal, the annealing process is repeated a number of
times, so the depth to which this effect reaches, just like the
effect of actually removing copper, is more than what one would get
with just one normal anneal. In effect, then, that layer under the
fine silver is the fire stain layer, and it too is increased in
thickness over a normal anneal. In fact, that layer also plays a part
in helping the surface to not melt during reticulation, allowing the
process to work. But as you’ve found, it is fire stain, not a clean
silver surface. This is simply one unavoidable part of reticulating
sterling silver. Rather than trying to prevent it (you can’t, really)
or remove it (also difficult or impossible without damaging the
reticulated texture), the answer is to increase the fire stained
effect to get full coverage. What you do is fully finish your piece,
and then, the final step is a prolongued somewhat low temperature
anneal with the surfaces very clean, no protectant, etc. Then a
careful pickling and just the lightest subsequent finishing to
restore whatever level of polish you wish. If your surface was
polished well before you did this, then only very light work will be
needed, and the idea is to not cut through the fire stain layer, so
the whole surface is then a uniform fire stain color rather than the
color of clean silver. If it’s not spotty, that difference is not
obvious to the eye. More, traditionally a reticulated surface is
often patinaed with liver of sulphur to enhance the textures. Doing
this on the fire stained surface will further mask any difference in
color.

This solution to fire stain, by the way, is not unique to
reticulation. The famous historical silversmithing firm of George
Jensen (nor sure I spelled that right…) used this process as the
final finish on much of their hollow ware…

You can also repeat the process of multiple annealings and
picklings, as you did before reticulating, which can remove, again,
the copper oxides and copper that is near the surface. If you do
this, you then must be careful not to polish or otherwise work
through that thin layer of fine silver on the surface. Finishing with
a fine brass platers brush to burnish the surface, rather than
actually buffing it, is one good way (just as it’s a good way to help
prepare the initial surface for the process.)

Hope that helps
Peter Rowe

Eva, you might want to look at Reactive Metals “Crinkle”. It is a
Bi-metal consisting of a thick layer of fine silver fused to a top
layer of 80/20 reticulation alloy. This configuration allows
reticulation without the standard heating, pickling, brass brushing
routine, routine, etc., etc. Crinkle can cut and formed and then
reticulated. Just take it to a high heat once and the surface begins
to crawl. A variety of torch techniques can be applied. Take up to
where it begins to shine and you can drop other metals and grains on
and they will fuse in place. Even stir it around with a pick…
Reticulation alloy is essentially IT Solder. It will flow on the
surface of fine silver.

Bill
Reactive Metals Studio, Inc

Are you using reticulation silver? (Usually 80/20 = 80% copper and
20% silver.) Even when you use reticulation silver, you still need
to depletion gild it.

And use a strong pickle such as Sparex. Citrex won’t do the job.

Search the Ganoksin Archives for more info…everything you ever
want to know about building jewelry is in the Ganoksin Archives.

Sandra

Are you using reticulation silver? (Usually 80/20 = 80% copper and
20% silver.) 

errrr…don’t you have that reversed? 80% silver to 20% copper…

Are you using reticulation silver? (Usually 80/20 = 80% copper and
20% silver.) Even when you use reticulation silver, you still need
to depletion gild it. 

I would like to correct wildly popular, but nevertheless mistaken
notion about reticulation.

I have no idea, where this originated that reticulation is done with
80/20 alloy. The falsehood of this idea is very obvious, simply
because we have a lot of reticulated pieces, which are hallmarked,
which cannot be done with 80/20 alloy.

Another problem is with this alloy is that firescale is unavoidable.
The only difference is whether it visible or not, but it is there.
The product of reticulation with 80/20 alloy is very brittle, with
very limited application, and etc… The list of why this is bad idea
is very long.

Reticulation craze started after some Faberge pieces, executed with
technique, which is known as “samorodok” reached the market.
Samorodok does not require depletion guilding, and it is done with
alloys of 95 to 97 percent of silver.

If you ever have a chance to see this technique close up, and
compare it to contemporary examples of reticulation, the difference,
in vocal terms, is ear shuttering.

Leonid Surpin

but I run into something that looks as heavy firestain which is
almost impossible to cover by depletion gilding 

Eva, try bright-dipping (pickle + hydrogen peroxide) the silver now
and then, to get rid of the red firestain, which is probably cuprous
oxide.

Judy Bjorkman

This solution to fire stain, by the way, is not unique to
reticulation. The famous historical silversmithing firm of George
Jensen (nor sure I spelled that right...) used this process as the
final finish on much of their hollow ware... 

It is Georg Jensen, no “e”. And he personally and the Jensen
workshop today uses fire stain in this way. The surface of hollow
ware and much of his jewelry is planished. The resulting dimples
remain dark and the slightly raised sections wear bright. It is a
lovely finish that Jensen compared to moonlight.

Jensen is one of my favorite artists and an inspiration since I
first picked up a hammer. There are many books available on his work
and quite a few museums, even in the US, have examples of his work in
their metals collection. The Denver Art Museum has a nice selection
of his hollow ware. One of the most beautiful examples of flatware
and hollowware is magnolia blossom. That pattern is still made by
hand. If you ever have the chance to visit Copenhagen, a trip to the
Jensen museum is a must.

Judy Hoch

In Jewelry Concepts and Technology by Oppi Untracht, Chapter 9
"Surface Ornament with Heat/Metal Fusion Techniques" second section
"Metals Used for Reticulation," Mr. Untracht states "Pure silver can
be reticulated but more usually silver copper alloys ranging from
92.5-80% silver are used. Pure and alloyed copper (and silver) were
commonly used by Faberge and plain copper and its alloys can also be
reticulated.

"When using silver of 820/1000 quality, a common European alloy…"
and so on 80/20 copper/silver ‘reticulation silver’ is readily
available from Rio Grande, and, is pretty commonly accepted as A
metal for reticulation. However, I imagine that anyone who has put
torch to sterling of fine silver has at some point caused
reticulation to occur, possibly to their regret and frustration. So,
in more words, metals reticulate under the proper conditions.

As to brittleness, Mr. Untracht describes the effects of “heat
concentration and temperature of the flame” as being a crucial
factor in “the creation of thermal stresses and grain growth
distortion in the metal”." This statement does lead one to consider
brittleness. Later on in the section titled “Using Reticulated
Sheet”, Mr. Untracht reminds us that there is a limit to the amount
of shaping and bending the sheet will take before it cracks, though
cracks can be repaired by flooding them with solder."

I have absolutely no doubt Mr. Surpin, that you have seen hallmarked
pieces of reticulated metal. When I see hallmarked reticulated
silver, I know that the torch bearer used sterling or fine silver, if
I see reticulated metal with no hallmark, I know the torch bearer
used something else.

Mr. Untracht has a wonderful description of the dynamics of
reticulation. In fact his book Jewelry Concepts and Technology is
fabulous reading.

Best wishes to all,
Sandra

When using silver of 820/1000 quality, a common European alloy... 

I would like to know since when 820/1000 quality became common
European alloy? There are some war time pieces as low as 800/1000,
but it is an exception. Common European alloy is 925/1000, also known
as sterling.

and so on 80/20 copper/silver 'reticulation silver' is readily
available from Rio Grande, and, is pretty commonly accepted as A
metal for reticulation. 

It may be available, but accepted? Accepted by whom? And what is
special about 80/20? If one wants the lowest melting point it should
be 82/18. If one does not care about hallmarking, why not do it on
pure copper. Pure copper is great for reticulation. What is the logic
behind 80/20?

Leonid Surpin

Hi,

At least in Sweden we use (830/1000), called verksilver (google
translate suggests works silver) mainly in cutlery (knife blades). I
made a silver thimble many years ago for a guy wanting to hand sew
in sheep fur - he had huge hands and couldn’t find a commercial
thimble fitting. I used (830/1000) as the top of the thimble for
strength.

830/1000 is also sometimes used in larger silver pieces (for
strength) that are supposed to be regularly used.

The back side is obviously that it tarnishes quickly - has to be
cleaned every so often. Sometimes this is being overcome by
electroplating fine silver on top.

I don’t think you can hallmark anything below 830/1000 in Sweden -
should then be stamped with 830 instead of the normal 925 (for
sterling)

R G D S
Lars Dahlberg

If one wants the lowest melting point it should be 82/18. 

72/28 is the eutectic alloy which at 1435 F has the lowest melting
point in the silver copper system.

James Binnion
James Binnion Metal Arts

How useful reticulation is depends on what your goal is, if
reticulation fits into the design concept you are working toward,it
is useful. If it is just a technique to beat the crap out of if you
have no direction, probably not too useful.

My opinion is that most people do not have a clue what they are
talking about when discussing reticulation.

There are a few examples of what I believe reticulation should be,
traditionally, and as used in Art Jewelry on Harold O’Connor’s
website Harold O'Conner - Goldsmith Arts

Harold has his work in various jewelry books by different authors.
Oppi Untract and Charles Codinas’s notably. My opinion is that Harold
has mastered the art of developing pattern, and then he granulates
some of the reticulated pattern. There is another person on this
forum who incorporates reticulation into her work and she does very
nice work. I will let her make her website known if she chooses to
do so. (Hi J.H.)

Most of what I see that is called reticulated is just heat damaged
or heat tortured. No fine development of any pattern.

Good reticulation, in my opinion, looks like bare mountainous
regions that have good topography that you see from an airplane, a
lot of depth and detail.

The reason 800/1000 silver is used is that when heated and pickled 5
times, fine silver surface is developed, alloy is in center, and when
this is heated correctly, the inside liquifies and the external skin
does not, and the metal develops a pattern with great detail.

Reticulation is usually best done with 26-30 gauge sheet. Sections
of reticulation are used with fabricated sterling parts to create a
structure, the reticulated portions are flat or very slight convex
or concave. This done for two reasons, brittleness of the metal, and
loss of detailby over working the shape.

Good reticulation is a skill, not an accident.

It is not important for me to be right, it just happens when others
are wrong.

Richard Hart G.G.
Denver, Co.

72/28 is the eutectic alloy which at 1435 F has the lowest melting
point in the silver copper system. 

While it is metallurgically correct, it should never be considered
as a part of goldsmith/silversmith repertoire. 820 out of 1000 is the
lowest silver content alloy, that ever to be found in one’s shop. If
you go bellow that, in starting at 800/1000 and lower, the formation
of verdigris on the surface is a real possibility. If one has cuts on
hands and handles item with verdigris on the surface, a very serious
consequences can follow. One of the Borgia methods for elimination
enemies was a prick with copper needle, soaked in vinegar. Copper
reacts with vinegar, forming verdigris on the surface.

Leonid Surpin

Good reticulation, in my opinion, looks like bare mountainous
regions that have good topography that you see from an airplane, a
lot of depth and detail. 

De gustibus non est disputandum is a good principle to uphold, but
the reasoning is not entirely correct.

The raison d’EAtre of reticulation is to imitate the surface of the
nugget. That is what samorodok means translated from russian. I have
seen some well published authors on the subject, getting this point
wrong, among many others. They translate it as self born, which is
reasonable translation for someone not knowing the language, but it
is also incorrect. It is not a minor point, because they derive the
explanation of the technique from the name, and invariably getting it
wrong.

The reason 800/1000 silver is used is that when heated and pickled
5 times, fine silver surface is developed, alloy is in center, and
when this is heated correctly, the inside liquifies and the
external skin does not, and the metal develops a pattern with great
detail. 

If the purpose of the technique to obtain look of mounting ranges, it
may be fine technique. I am being somewhat of a purist, has to insist
on surface observed on nuggets, in their natural form. To obtain that
type of a surface, metal should not be taken to where core is liquid.

Reticulation is usually best done with 26-30 gauge sheet. Sections
of reticulation are used with fabricated sterling parts to create
a structure, the reticulated portions are flat or very slight
convex or concave. This done for two reasons, brittleness of the
metal, and loss of detailby over working the shape. 

When trying to understand a technique, is alway good to consider the
history of it. Samorodok was primarily used for cigarette cases. As a
past smoker, I know that cigarette cases takes a lot of abuse, so
they must be sturdy. The surviving examples were obviously made from
heavier gage than 26. We also have to consider how the cigarette case
is made. While it is possible to reticulate already formed object,
examination of some of the cases, clearly shows that sheets were
reticulated, and than formed. This excludes the possibility of using
800/1000 alloy. It should be noted that brittleness is not the only
reason to reject low grade alloys for this technique.

I should mention that if you like, what you see as contemporary
examples of reticulation, than you should ignore everything I said,
because I am interested in the technique, as it was practiced in the
past, not present.

Leonid Surpin

While it is metallurgically correct, it should never be considered
as a part of goldsmith/silversmith repertoire. 820 out of 1000 is
the lowest silver content alloy, that ever to be found in one's
shop. If you go bellow that, in starting at 800/1000 and lower, the
formation of verdigris on the surface is a real possibility. If one
has cuts on hands and handles item with verdigris on the surface, a
very serious consequences can follow. One of the Borgia methods for
elimination enemies was a prick with copper needle, soaked in
vinegar. Copper reacts with vinegar, forming verdigris on the
surface. 

Japanese metalsmiths routinely used an alloy called shibuishi which
is 75Ag-25Cu or even lower amounts of silver in some instances. I
have never seen verdigris on modern or antique shibuichi items. And
unless you routinely soak copper goods in vinegar for extended time
periods you are not going to create much copper acetate (verdigris)
anyway. Add to that the LD50 for copper acetate is 710 mg/kg so
while it is toxic it would take more than a simple needle prick with
a copper needle and little vinegar.

James Binnion
James Binnion Metal Arts

I should mention that if you like, what you see as contemporary
examples of reticulation, than you should ignore everything I
said, because I am interested in the technique, as it was practiced
in the past, not present. 

Google Samorodok and one of the images that comes up is a silver
cigarette case, in my opinion my description is accurate, for both
the antique technique, and the technique as practiced by Harold
O’Connor.

Harold’s pieces and the antique example are identical to my eye.
Either example does not look like any nugget I have ever seen, gold
orsilver. Perhaps the Russian translation makes the metalwork appear
different to someone who speaks Russian. I have experience with
reticulatiion, and the cigarette case I saw probably is the range of
gauges I mentions. Thicker metal does not give as severe a pattern
as thinner, however I do not think that the antique cigarette case
example does not meet the criteria for Russian reticulation even if
it was it wasdone in Finland

The example of the Fabrage gold frame,

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

seems to me to have a wonderful pattern, however it is quite
different from the silver antique cigarette case, to my eye. I see
where, in certain portions, especially the back, there more of a
nugget look. There is still some “dendritic” looking pattern on the
front, these do not look like a nugget pattern. Dasvidaniya,

Richard Hart G.G.
Denver, Co.

And unless you routinely soak copper goods in vinegar for extended
time periods you are not going to create much copper acetate
(verdigris) anyway. Add to that the LD50 for copper acetate is 710
mg/kg so while it is toxic it would take more than a simple needle
prick with a copper needle and little vinegar. 

I usually do not worry too much about things, but if we are
replacing pickle with ascorbic acid, how can we ignore verdigris. A
little bit of inconsistency here.

Leonid Surpin

I usually do not worry too much about things, but if we are
replacing pickle with ascorbic acid, how can we ignore verdigris.
A little bit of inconsistency here. 

Ascorbic acid? I have never heard of anyone using ascorbic acid for
pickle and it would not make verdigris anyway. Verdigris is copper
acetate it is made from copper and acetic acid (vinegar) reaction.
And frankly any copper salt is toxic so you might as well have the
same concern for copper sulfate from traditional sulfuric or sodium
bisulfate pickle. It is slightly more toxic than copper acetate LD50
350 mg/kg.

The whole issue is bogus.

James Binnion
James Binnion Metal Arts

Leonid,

I usually do not worry too much about things, but if we are
replacing pickle with ascorbic acid, how can we ignore verdigris.
A little bit of inconsistency here. 

You may have made a mistake. There is Ascorbic acid, Citric Acid and
Acetic Acid which need to be considered in this reference. Based on
my ancient chemistry knowledge, I am pretty certain that only the
latter will produce verdigris when reacting with copper.

All the best,
j
J Collier Metalsmith