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Fire scales after texturing


#1

When I first started doing this work and was trying to make a mirror
finish on the pieces, I had a problem with firescale in the final
stages of polishing. Now I am texturing most of my pieces instead of
polishing highly. My question is, will firescale show up at some
time later if it is not visible after texturing?

J. S. Ellington


#2
       When I first started doing this work and was trying to make
a mirror finish on the pieces, I had a problem with firescale in
the final stages of polishing. Now I am texturing most of my pieces
instead of polishing highly. My question is, will firescale show up
at some time later if it is not visible after texturing? 

A fire stain (fire scale is the black oxide left after heating,
which pickles off. Fire stain is the grayish shadow you find when
you polish) surface will probably look fine with the texture. But if
it oxidizes over time, the fire stained portions will tend to oxidize
differently than the clean sterling, so then the surface may look a
little blotchier than it otherwise would have.

Nevertheless, I’m forced top wonder why, every so often, a new crop
of folks here on Orchid come and start discussing fire scale and fire
stain, and their apparent inability to prevent it.

You don’t have to put up with the stuff. Learn to use prips flux,
guys. It’s a fuss and bother, sure. But it’s really cheap to make,
safe to use, and does indeed, when used correctly, prevent the
formation of fire scale and fire stain.

I’ve posted, several times over the years, a somewhat wordy article
here on Orchid about the use and preparation of prips flux. Go find
it.

There are, if I recall (I’m not looking at it right now, so this is
memory only, which may be wrong) a couple minor errors in that
article when you find it.

First is the spelling. It’s Prips flux, not Pripp (with two "t"s).
Jack Prip doesn’t spell his last name with two t’s, and the flux
named after him shouldn’t either. So don’t perpetuate my initial
error…

Second, and I don’t remember if I corrected this or not in the
postings you’ll find in the archives. At one point I wrote the
simple recipe of a quart of water with 80 grams each of borax and
TSP, with 120 grams of Boric acid. That amount of chemical won’t
quite dissolve in a quart of water, so then you’ve got to bother with
adding additional water. It WILL dissolve, barely, in a LITER of
water. For a quart, use 64:64:96. The important thing is the
2:2:3 ratio anyway, but the above quantities will be easier to mix up
if you’re not trying to dissolve more than will go into the container
you’ve got… Note that some school studios mix these amounts with
a gallon of water. makes for a more dilute mix, which is cheaper and
fine for students who are really happy and extravagant with spray
bottles. But the more concentrated solution actually is easier to
apply, especially with an atomizer type sprayer rather than a
trigger bottle. Atomizer types work a lot better, with a more even
spray of smaller droplets.

Please feel free to contact me either off list or on, if you’ve got
trouble using prips flux. it DOES work. Then you don’t have to
worry about how to remove it, if you’ve never allowed it to form in
the first place. The time spent using the flux is much more than
saved in the clean up and polishing stages.

Peter Rowe


#3

J.S.~ I have one heck of a time with fire scale, and discovered
that texturing the piece only somewhat distracts the eye from seeing
the lesser scale. I don’t consider texturing to be a permanent fix
or a good one, Plating seems to be the best if it will not be
polished a lot later,

Perhaps we see more than others, our eyes are supposed to detect
slight color change in metal and stone, My housemate could miss just
about ANY color, size, texture, or functional difference in just about
anything, haha… so there are those customers who will be easier to
please. But I would not push it with considering texturing as an
all-the-time fix… Sigh, if only it were…

Maybe you may find (as did I) that using more heat for a shorter time
helps reduce the frequency and severity of firescale.

Frif


#4

To all new members of Orchid, I have to second Peter Rowe’s advice
on Prips flux. Like everyone else, I fought the fire stain problem
for years. I had always used the old alcohol-boric acid
formula,which didn’t work half the time.The first time I saw Peter
put the formula out on Orchid for Prips flux, I immediately prepared
a batch and tried it and said good-bye to fire stain.I never even
concern myself with it now. Like he says, it’s easy to make, easy to
use.There’s literally no excuse for having fire stain since this
formula works.When making a light weight pair of earrings or
something similar in weight,I sometimes don’t use it,but when making
a heavy oval belt buckle, bolo/bola tie,or bracelet , gotta have
it.Thank God for Jack Prip,Fred Fenster, and Peter Rowe.Best wishes
to all, John Barton PS Dave Sebaste, please don’t you get too far
away:-) surely God in heaven has good things in store for you.


#5

Hi Peter I’ve always been aware of scale and stain, having been in
this business for over 25 years. I’ve long known how to deal with
it, both preventing and removing, when I am soldering. Until
recently, my silver production was small and mostly limited to
fabricated pieces. Now I am producing a small line of charms and
other pieces that are cast in silver. I don’t do my own casting for
a lot of reasons, so I am sending the work out to a contractor. On
the smaller pieces, the stain is so deep that I can’t remove it
without destroying the detail, or wearing through thinner areas. I
have no control over their casting process, so it remains for me to
remove the stain afterwards. Any suggestions? I have used their
’low-oxidizing’ silver, which gives much better results, but it is
much softer. This is acceptable on some pieces, not on others. It is
also harder to intentionally oxidize on those pieces that need it.
Thanks, Jim


#6

Frif,

I continue to believe (as many Orchadians has stated often) the best
way to get rid of fire scale is to prevent it in the first place. I
teach my students a very specific protocol of - alocohol wash, A
SOLID COAT OF PRIP’S FLUX, then self-pickling flux on the join
(Battern’s, Aqua-flux, My T Flux, etc) place the solder and heat.
This prevents 90% of the fire scale at least and makes clean up a
snap! You are right that the amount of heat also has an effect but
would suggest not using more heat for shorter time rather a bit less
heat in the proper place will give better results. If the heat is
too high, it will burn through the Prip’s flux and result in fire
scale anyway! Check the Orchid archives for further
Cheers from Don at The Charles Belle Studio in SOFL where simple
elegance IS fine jewelry! @coralnut1


#7

Yes. Firescale can be a problem later. If the owner uses a dip to
clean the piece, the surface will gradualy wear and the copper layer
that is the firescale will tarnish more quickly. Even if not using a
dip, my experience is that whever their is firescale, there will be a
different rate of tarnishing. On pieces that are desogned to be
oxidised to some degree and purposely rather roughly made, it doesn’t
matter as much. If you are going for some thing more refined, I’d get
rid of the forescale and then texture. I’d be interested in what
others have to say. Jan


#8

Jim, I have some pieces cast and never have a problem with them.
Perhaps you need to use a different caster. I use Race Car Jewelry
and have been extremely pleased with their work.

Deb Karash


#9

I have a different question re preventing fire scale: Will Prips work
for copper too? I know this is a bit different sort of fire scale,
but I have been working a bit with copper plus silver; and not being
able to use (because of the silver) the nitric acid bath usually
used for copper, I end up with the usual horrendous dark scale that
can only be removed by sanding.

Margaret


#10

Jim, I was also going to suggest a different caster. Some firescale
will just happen from time to time…but if you are consistently
having the kind of problems you describe, you need to either complain
and get results or take your business elsewhere. We use Sampson
(www.sampsonandsoncast.com ) Small family operation, 3rd generation
silversmiths and they do excellent work. They always come through for
us when we get hit with deadlines.

Mike Dibble
Black Horse Design
www.black-horse-design.com


#11

Hi Jim,

I have no control over their casting process, so it remains for me
to remove the stain afterwards.  Any suggestions? 

Don’t mean to sound like a wise guy here, but you might try a new
caster. Daniel Grandi (racecarjewelery.co), a frequent contributor
to the Orchid list is superb caster.

Dave


#12

Thanks to Dave and all the others who are giving me good
recommendations on casters. I suppose I have just been suffering
from the reluctance to change. I have used this guy for over 10
years, and have never had real problems with him. Now that I am
doing large quantities of silver, and on pieces that I need to keep
my labor down on to be profitable, I see that it may be time for a
change. Perhaps a new contractor will be a revelation. Thanks again.
Jim


#13

Margaret,

By all means Prip’s flux can be used with copper. I have one
student who loves to work in copper. As you know, copper eats heat
and loves more and this can, as you say, result in horrendus fire
scale. We experimented with Prip’s and found it did beautifully.
Just make sure the piece is well coated with no breaks. Good luck.
Cheers from Don at The Charles Belle Studio in SOFL where simple
elegance IS fine jewelry! @coralnut1


#14
Thanks to Dave and all the others who are giving me good
recommendations on casters. 

May I add my recommendation for a caster? I’ve been using Larry Paul
in Philadelphia for twenty years now, and I’ve been totally happy
with their work. I’ve handed them some real problems over the years,
and they’ve risen to the occasion, whatever strange stuff I’ve given
them.

Larry Paul, Caster
740 Sansom St
Philadelphia PA 19106
215-928-1644
Lpaul @ aol.com

Janet Kofoed