Hi Helen,
I am not an expert but I think Prips is not a great flux for
soldering, so put your ordinary flux on first and then coat with
Prips.
There was a long thread on this some time ago, have a look in the
archives, I’m sure you will find it all there.
regards Tim.
Dear Leonid,
My book said the cherry red thing but as you said it never mentioned
anything about doing it in the dark or how long to hold it at that
temperature. I guess it depends on the size of the piece of silver
(or whatever metal) to be annealed. I find it difficult to keep it at
a steady temperature for any length of time as you have to keep
moving the torch flame and if you move it too far away, it is no
longer at the desired temperature. It’s all very confusing!
Helen
I started this thread and I have had some very interesting responses.
Yes, Helen, it’s been interesting. I think it’s gotten a little out
of hand, myself, for the readers out there. What happens on an atomic
level is interesting, but not very practical. The important thing to
understand (speaking not so much to you as to the rest of those
interested) is how to anneal. Mr. Surpin said it, though I believe
his English is lacking. He said to heat to cherry red, which is just
the red that shows in a darkened room. In English we call that a dull
red - cherry red is more like 1500F. But he has it right, still.
Annealing of silver, copper and most gold is at a temperature I think
most novices overestimate - 900 - 1100F, way below soldering
temperature. Ideally, as above, if you turn out the lights and heat
until the metal is just red, that’s it, and that’s enough. If you
overheat your metal a lot, you will get cracking and rampant
firescale. Cracking doesn’t mean that it will just crack all by
itself, which is why you can overheat something like granulation in
silver and it will seem fine. It’s when you work it further that the
cracking can happen. I tend to overheat a bit (like 1100F) when
annealing, too, because I’m usually working on something that’s more
forgiving and casual - rolling metal and annealing 6 times or
something. But the more work you are doing, the more it matters. If
you’re annealing your work 500 times (yes, really), then each time is
much more important, because the damage of overheating is both
cumulative and irreversible, without remelting the metal. And if you
anneal to the proper temperature on a small piece, turn off the torch
and put it down, by then the piece will have lost it’s redness, and
it is of no consequence whether you quench it or not. I quench in
pickle because I’m an adult and it also strips the surface nicely -
just rinse thoroughly. All of this applies to silver, copper, bronze,
and most yellow golds. Nickle bearing white gold can behave
differently - I’ve found they can harden if you don’t quench them,
sometimes, as can some other alloys you may find or make. And of
course steel and exotics are a whole different set of rules entirely.
The best book instruction, I have ever seen, is to anneal at cherry red, which is technically correct. What is never mentioned is that cherry-red must be observed in the dark. If one anneals at normal shop condition, it would result in over-heating, and over-heating is deadly.
I wonder if some of the new IR (Infra Red) non-contact temperature
guns could be used to determine when the temperature is just right
for the annealing. Two of the issues with using the IR “guns” is
that: 1) the inexpensive guns have a set emissivitiy (sp?) (the rate
IR is emitted by the source being tested) and it may not be right or
the same for each alloy. and 2) the area is a cone shape which
blooms out (area gets larger) the farther away one holds the gun I
think that once someone got familiar with using a particular IR
“gun” on a particular alloy; it could be used dependably.
Dan Wellman
You must have had a very interesting education Jim. Do you have a degree or higher in metallurgy? My chemistry degree is long forgotten as I've not used it for years and as such I have found your posts very interesting.
Interesting is one way to put it 
At the age of 17 I ended my
relationship with what passes for formal public education here in
the US. The powers that be would not let me take more than one art
class per semester and the jewelry arts class was the only thing
there that interested me so I quit. I was bored to death, I am lucky,
if I was a little younger they would have labeled me ADD and just fed
me lots of drugs to make me compliant. After leaving high school I
briefly attended a trade school studying Commercial Art and
Advertising but I am not an illustrator and really could not see
myself creating ads for a living. I went to work for a sculptor in
Colorado and while there met someone who worked in the electronics
industry (HP). He showed me this brand new thing (this was 1975)
called a microprocessor and I got hooked on the possibilities of it.
I decided that I wanted to learn electronics and through some
convoluted logic determined that the US Navy would pay me to learn
electronics and volunteered. So I went to various electronics
training schools in the Navy and became an electronics technician on
nuclear submarines. I served for a little over 8 years. During the
last 4 years of my service I was in the San Francisco area (Vallejo)
and saw an article about a fellow named Alan Revere who had a jewelry
making school. I started taking night classes and weekend workshops
at the Revere Academy of Jewelry Arts. It was during this time period
that I got interested in mokume-gane, since no one was teaching it
near by I decided to teach myself. This was where I learned that I
did not know anything about metals and began trying to learn more
about them so I could understand what was going on during the
lamination process.
Also I had decided I was not career military and to get out of the
Navy and go back to school to get a degree in metal arts. My ex wife
was a student at the time and we could not afford to have both of us
in school so I went to work in the Silicon Valley at a company called
SRI International. SRI was a contract R&D firm that had a significant
range of projects ranging from life sciences to engineering and
materials. SRI is an interesting place it is a combination of a
university type research lab and not for profit business. They have
developed some well known things over the years, the first laundry
detergent (Tide) back in the 50’s.
This funny thing called the internet was a DARPA program that SRI was
a part of. We were the second of three nodes on the original internet
back in the 60’s and did a large amount of the development of it. The
computer mouse and a few other more or less well known inventions
have come from SRI. One of the great things about SRI was if you
wanted to know about just about any kind of science or engineering
there was someone there who was an expert or at least fairly
knowledgeable in the subject and most of them would take the time to
talk to you if you had a question.
Another great thing was the libraries, each lab had one and there was
a main one as well. Because we were doing research and development we
had to not only come up with new ideas but had to turn those ideas
into concrete working (hopefully) models. Probably the most important
thing I got from SRI was learning how to find and take it
and apply what I needed to the job at hand. I look at SRI as my on
the job training engineering bachelors and masters degree program. I
was there for 13 years.
I spent nights and weekends making jewelry in my basement studio and
lunch and after work reading in the libraries or listening to people
who had lots of unique explain the basics to a novice
(me). I left SRI to follow a jewelry carer in the 90’s. I have
continued to try to gain more knowledge of metals by attending events
like the Santa Fe Symposium on Jewelry Manufacturing and Technology,
continuing to read and by finding experts who are willing to take the
time to explain things to the novice.
So there is a very long answer to your question,
Jim
James Binnion
@James_Binnion
James Binnion Metal Arts
360-756-6550
I find it difficult to keep it at a steady temperature for any length of time as you have to keep moving the torch flame and if you move it too far away, it is no longer at the desired temperature. It's all very confusing!
I have never found it important to hold any length of time at
annealing temperature.
I have always stopped once it reached. I know that some alloy
manufactures recommend that metal to be held for some time at
annealing temperature. That is required if you want to completely
restore metal to the original state of workability. In practice, I do
not think it is necessary and danger of over-heating outweighs any
potential benefits it may bring.
Leonid Surpin
I am not an expert but I think Prips is not a great flux for soldering, so put your ordinary flux on first and then coat with Prips.
I solder with it. It is as good as any borax, boric acid based flux
but has the same drawbacks high flow temperature and not very fluid.
So you need to push the solder down through it and into contact with
the base metal. If I need a more aggressive fluxing action I use a
white or black paste flux.
I apply the prips first then with the work still hot place a small
amount of the paste flux at the joint. I find if I do it the other
way around the bubeling of the other flux damages too much of the
prips layer and I end up with fire stain.
Jim
James Binnion
@James_Binnion
James Binnion Metal Arts
360-756-6550
Hi Jim,
So there is a very long answer to your question,
No problem, I like a good read and it was a good read!
I was bored to death, I am lucky, if I was a little younger they would have labeled me ADD and just fed me lots of drugs to make me compliant.
Ooh don’t get me started on that one! As an ex high school science
teacher at a school with a very high percentage of what we in the UK
term special needs, I have had my fair share of teaching children
who were diagnosed with ADD and fed Ritilyn and who were quite simply
either suffering from what I can only describe as a case of bad
behaviour or like yourself were clearly very intelligent and were
not being challenged enough.
He showed me this brand new thing (this was 1975) called a microprocessor and I got hooked on the possibilities of it.
My hubby would be envious as he’s an electronics/computer nut!
Although in 1975 he was only 5.
Alan Revere who had a jewelry making school.
By all accounts, he’s an excellent teacher. I have made it an
intention to buy one of his books.
It was during this time period that I got interested in mokume-gane, since no one was teaching it near by I decided to teach myself.
You obviously went in the right direction career-wise, judging by
the quality of your work, it is outstanding.
This funny thing called the internet was a DARPA program that SRI was a part of. The computer mouse and a few other more or less well known inventions have come from SRI.
Didn’t Mr Wozniak of Apple Macintosh fame take credit for such
things?
Because we were doing research and development we had to not only come up with new ideas but had to turn those ideas into concrete working (hopefully) models. Probably the most important thing I got from SRI was learning how to find and take it and apply what I needed to the job at hand. I look at SRI as my on the job training engineering bachelors and masters degree program. I was there for 13 years.
Yes, when I was reading this paragraph, I was thinking you earned
your Bachelor’s and PhD by experience, possibly a better grounding
in a given field than University, as you HAD to find the answers and
may have been out of a job if you hadn’t.
I spent nights and weekends making jewelry in my basement studio and lunch and after work reading in the libraries or listening to people who had lots of unique explain the basics to a novice (me). I left SRI to follow a jewelry carer in the 90's. I have continued to try to gain more knowledge of metals by attending events like the Santa Fe Symposium on Jewelry Manufacturing and Technology, continuing to read and by finding experts who are willing to take the time to explain things to the novice.
You seem to have some excellent conferences over there in the
States, although it’s a huge country so you probably have to travel a
lot to attend such things.
If you call yourself a novice after all this time and when you’re
producing the results you do, then I dread to think what that makes
those of us who have only just started in this field!
Thanks once again for sharing that with us. Your posts are always
interesting.
Regards,
Helen
I wonder if some of the new IR (Infra Red) non-contact temperature guns could be used to determine when the temperature is just right for the annealing. Two of the issues with using the IR "guns" is that: 1) the inexpensive guns have a set emissivitiy (sp?) (the rate IR is emitted by the source being tested) and it may not be right or the same for each alloy. and 2) the area is a cone shape which blooms out (area gets larger) the farther away one holds the gun I think that once someone got familiar with using a particular IR "gun" on a particular alloy; it could be used dependably.
The short answer is no it will not work.
The longer answer is that the IR thermometers rely on a physical
property of the material to be measured called emissivity (http://
en.wikipedia.org/wiki/Emissivity). Emissivity is the ratio of energy
(in this case IR) radiated by the material to an ideal black body
radiator at a given temperature. The black body would be an ideal
emitter of energy and real world materials are somewhat less
effective as radiators. Metals especially shiny metals have a very
low emissivity so the amount of IR emitted by them is very low. This
makes it difficult for the IR thermometer to dicern the amount of
energy and thus doesn’t give an accurate temperature reading. Second
the IR thermometer reads the average temperature of the energy in
its focal cone and if you do not have it accurately focused on just
the surface you want to measure you will get an erroneous
measurement. Third you cant measure while the torch is on the work or
the temperature of the hot gas of the flame will be averaged into the
reading. Likewise the flux coating on the metal will potentially
have a different temperature than the metal and give another error
source to the measurement.
There are ways around many of these problems but now you are talking
about a very expensive instrument, in the thousands of dollars. Not
the inexpensive one that are starting to show up in various
catalogs.
James Binnion
@James_Binnion
James Binnion Metal Arts
360-756-6550
Hi John,
Oh the atomic level thing was just my pedantic side coming out again
I’m afraid - sorry.
It’s all beginning to make a bit of sense. I began this thread as
people were talking about quenching being a necessary part of the
process as opposed to the way I was using it - as a means of moving
on quickly to the next step!!! Then in answering my queries regarding
quenching, it became apparent that I also knew nothing about
annealing and so I started out on a quest to understand that.
Yourself and others have made it more understandable regarding the
temperature required but as Jim Binnion I think said, it is a
temperature AND time thing and that it needs to be kept at the
desired temperature for enough time for the crystals to grow. I
suppose there’s no way of knowing exactly how long but have you or
anyone else got any advice for me as to how long to keep my silver
at cherry red for?
Many thanks in advance and for past answers.
Helen
Preston, UK
I agree with James Binnion.
I apply the prips first then with the work still hot place a small amount of the paste flux at the joint.
Although in my case, I use Battern’s liquid flux and with an insulin
syringe, place a tiny drop on the joint. When the flux goes clear, I
put the solder on the joint. Works for me.
Judy in Kansas, who is heading for cooler temps in the mountains
soon.
Yourself and others have made it more understandable regarding the temperature required but as Jim Binnion I think said, it is a temperature AND time thing and that it needs to be kept at the desired temperature for enough time for the crystals to grow. I suppose there's no way of knowing exactly how long but have you or anyone else got any advice for me as to how long to keep my silver at cherry red for?
This is where many run into trouble. The hotter it is the less time
it takes to get a full anneal so the temptation to speed things up
makes for the possibility of over heating. Also some alloys need
longer times just because of their composition. If you look up
industrial on annealing sterling you will see temperature
ranges of 900-1000 F (480-535 C) at the high end this is just a
barely visible color in a dark room but industrially they are doing
it in a furnace with a controlled atmosphere and the cycle time is
quite long as it is often furnace cooled. But even with furnace
quench tanks in the controlled atmosphere the cycle times are 15-30
min to get to full heat. We obviously can’t hold a torch heat at such
a low temperature for 15-30 min so we try to keep the temperature
down to a dim glow that is probably more like 1150 F (621 C) for a
more brief period of time.
Jim
James Binnion
@James_Binnion
James Binnion Metal Arts
360-756-6550
Jim,
That is the way I do it too. Spray it all over. I make my own Prips
flux. never have any firestain. recipe if anyone needs it:
80g borax
80g tri-sodium phosphate
120g boric acid
1.25 qt water
mix well and strain
susan
I haven’t paid attention to this series this time, but you don’t need
to go to cherry red and if you do quench in water (never pickle)
almost immediately a little slow handling won’t hurt. Annealing is
practically instantanious at this temperature and too long will cause
rapid grain growth.
Each annealing step makes this worse. Large grain growth will ruin
the metal for further working and may cause later cracking. You can
only recover large grained metal by melting. I batch anneal in a
furnace and don’t get very hot (400- 450 C) but hold it longer–
grain growth is not a problem at this temperature. Commercial
annealing will be done in continuos belt furnaces with a protective
atmosphere. the temperature is higher but they also control the time
very carefully. Some of the cracking people claim may be just due to
grain growth by holding the metal too hot too long) Silver, copper
and gold will start to anneal at about 200C ( Brepohl says higher for
gold 400C) but this is not called for everywhere. Generally non
ferrous metal can be quenched rapidly after annealing. This is not
true for ferrous alloys which generally need slow cooling… Know your
metals. The best reference that is easy to buy ( except maybe for
price) is : Brephohl’s “The Theory and Practice of Goldsmithing”
jesse
I haven't paid attention to this series this time, but you don't need to go to cherry red
When I post my original post I said “cherry red in the dark” I never
said “dark room”. The difference is “dark” means absence of light,
“dark room” means some light is present. The actual color it will
translate in a shop is the judgement which needs to be made locally.
Besides I wonder what kind of cherries do sell now. Where I live they
are dark red.
It is a wrong emphasis on quench or not to quench. While important,
far more important is that metal should be stressed equally before
annealing.
Leonid Surpin.
Hi Jesse,
Thank you so much for replying. I’m a little confused though as a
number of people say it should be held at the annealing temperature
for a longer time and that just getting it to such a temperature
momentarily is a waste of time.
However, I can read up about it as I have just purchased and taken
delivery of the very book you prescribe. Having had a brief look
through it, it looks extremely informative.
Thanks again.
Helen
Preston, UK
Yes, this topic has been pounded into the ground. I’m very
concerned, though, about the use of the term “cherry red” in
relation to annealing. You can heat steel to cherry red and let it
cool slowly to anneal it, but that temperature has no place in
non-ferrous metal unless you’re melting it - or platinum. I don’t
know if people actually mean it, or misunderstand the
temperature/color thing. So, here’s a good listing of the standard
temperature/color, as has been passed down since the beginning of
time - it doesn’t try to use graphics, but it’s a good list. As with
all of these, the low-temp colors only apply to steel, because those
are oxide layers, but the red, orange and yellow is pretty similar
in most metals. The real point being that when you say cherry red,
this is what people think:
I will try to be as clear as I can on this subject. My apologies for
the nuclear physics stuff.
When we anneal, we want to move atoms in the original position or
close to it.
In order to do it, atoms need energy. The energy is supplied by the
torch. When we heat the metal, we transfer energy of the torch to the
atom composing the metal.
When we transfer so much energy that atoms can really move freely,
the metal start behaving like liquid. It melts.
But we do not want to do it in our case. We need to bring metal to
the temperature when atoms just starting to move.
How can we tell this magic moment? When the temperature is right,
some of the atom on the surface of the metal, due to direct contact
with the flame would acquire so much energy that electrons of such
atoms would start moving in high energy positions. Once these
positions are reached, they cannot be sustained for long, so such
electrons would fall back to the lower energy position, but not
necessarily to the original. In this process of falling back, the
excess of energy would be released and we can see it as metal begins
to glow.
The more intense the process, the brighter color of the glow. We want
to stop at the bare beginning, which can only be detected in the
dark.
I hope that trying to relate this process to the color of the
cherry, I did not cause anybody going to the supermarket and seeing
yellow cherry on display, going back to his shop and trying to anneal
at that temperature, because it would certainly cause metal to
evaporate.
Leonid Surpin
This is all getting very confusing! Well I now have my copy of Mr
Brepohl’s book “The Theory and Practice of Goldsmithing” and it’s
apparently a very good text book on the subject so I’ll see what he
has to say and re-read the posts on the topic and see if I can make
sense of it.
Thanks to all those who’ve helped.
Helen
Preston, UK
Hi John,
Thanks for your response to my query. This thread has gone a little
bit round the houses but I’ve had some good answers. I’ll have it
sussed in time and with more experience. I’ve printed out the table
in the link you gave. Thanks.
Helen
Preston, UK