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Finishing Castings-HELP!


#1

Hi,
I would like to know if it is necessary to “strip” unfinished castings
first before polishing. If so, what process is used. If not, what is the
first step to finish the cast piece?

I have used rubber wheels first, then tripoli and then red rouge on 14kt
gold pieces, and they never look “bright” to me. What am I doing wrong?

Thanks for any help you can give me.
Sincerely,
Marlene

Marlene DeMers


#2

Hi Marlene

Maybe I can help, but first I need to know the specifics.

What are the designs like? All curved surfaces, some flats etc…
What color gold and karat and your particular alloy/manufacturer?
New or scrap gold?
any micro-porosity in the castings?
Is your rouge buff contaminated?

Polishing is an art, and it takes years to get really good at it. A good
professional polisher can can do wonders for jewelry. In some shops the
polisher is the highest paid jewelry worker!

Handmade 18K and platinum gemstone jewelry. Fine die
and mold engraving. Diamond setting. Class rings/pins.
25 years experience in the jewelry trade. 515-469-6250

Marlene DeMers wrote:


#3

I assume that the piece is cleaned between trip and Red Rouge . . . never
the twain shall meet!

Jim

At 09:11 AM 10/11/96 -0800, you wrote:


#4

Jim Chambers wrote:

I assume that the piece is cleaned between trip and Red Rouge . . . never
the twain shall meet!

Jim

At 09:11 AM 10/11/96 -0800, you wrote:

Hi,
I would like to know if it is necessary to “strip” unfinished castings
first before polishing. If so, what process is used. If not, what is the
first step to finish the cast piece?

I have used rubber wheels first, then tripoli and then red rouge on 14kt
gold pieces, and they never look “bright” to me. What am I doing wrong?

Thanks for any help you can give me.
Sincerely,
Marlene

Marlene DeMers

orchid@ganoksin.com

orchid@ganoksin.com

Jim is correct and note that sometimes castings require the use of emery
cloth or similar(vibratory hones etc.) to remove the surface roughness
before you use the tripoli. Use one buff for the tripoli (clean in
ammonia with a toothbrush) and then go to seperate buff for the
rouge.Follow with a good cleaning again with ammonia and toothbrush then
a soft cotton polishing clothe …There are some pink wheels that are
usually knife edged that are good for hard to reach areas also.For a
more deep yellow color I sometimes boil in a solution of water with a
teaspoon or so of non-iodized table salt, one tsp. of alum and one tsp
of potassium nitrate or salt peter.Use a pyrex beaker or old coffee pot
and heat on a low setting.You also should anneal and then pickle your
castings in Sparex(or similar) solution heated to about 140 degrees…On
gold and silver before you anneal(by heating to redness and on gold just
allow it to cool but you can quench the silver while hot) dip in boric
acid and denatured alcohol to avoid heat discoloration before
annealing…Gavin…


#5

Hi Gavin,
Thank you for your help. I think I discovered the problem-I was not always
annealing before I finished the pieces.
Thanks again,
Sincerely,
Marlene

Marlene DeMers


#6

Thanks Jim for the help.
Sincerely,
Marlene

Marlene DeMers


#7

Hi Jeffery,
Thank you for answering my question. I will address your questions from below:

  1. The designs are rings with prongs (at least four), some with filigree
  2. They are 14kt yellow gold and I don’t remember the manufacter; I bought
    them many years ago in NYC (47th street).
  3. I believe they are new gold
  4. I did not see any micro-porosity in the castings
  5. How do I tell if the rouge is contaminated?

I think it is necessary for me to explain-that I have not done any work
with jewlery castings and finishing them for a number of years. When I
found this mailing list group, I started to think about going back into it.
But, I remembered that I never felt like I was finishing the bought casts
correctly-they looked okay-but not professional enough. So, I am asking my
questions based I what I remember when I was doing the work. I thought
that maybe jewelers use some kind of stripping process that I was not aware
of.
Thanks again for all your help,
Sincerely,
Marlene

Hi Marlene

Maybe I can help, but first I need to know the specifics.

What are the designs like? All curved surfaces, some flats etc…
What color gold and karat and your particular alloy/manufacturer?
New or scrap gold?
any micro-porosity in the castings?
Is your rouge buff contaminated?

Polishing is an art, and it takes years to get really good at it. A good
professional polisher can can do wonders for jewelry. In some shops the
polisher is the highest paid jewelry worker!

Handmade 18K and platinum gemstone jewelry. Fine die
and mold engraving. Diamond setting. Class rings/pins.
25 years experience in the jewelry trade. 515-469-6250

Marlene DeMers wrote:

Hi,
I would like to know if it is necessary to “strip” unfinished castings
first before polishing. If so, what process is used. If not, what is the
first step to finish the cast piece?

I have used rubber wheels first, then tripoli and then red rouge on 14kt
gold pieces, and they never look “bright” to me. What am I doing wrong?

Thanks for any help you can give me.
Sincerely,
Marlene

Marlene DeMers

orchid@ganoksin.com

procedures

orchid@ganoksin.com

Marlene DeMers


#8

Marlene DeMers wrote:

Hi Jeffery,
Thank you for answering my question. I will address your questions from below:

  1. The designs are rings with prongs (at least four), some with filigree
  2. They are 14kt yellow gold and I don’t remember the manufacter; I bought
    them many years ago in NYC (47th street).
  3. I believe they are new gold
  4. I did not see any micro-porosity in the castings
  5. How do I tell if the rouge is contaminated?

I think it is necessary for me to explain-that I have not done any work
with jewlery castings and finishing them for a number of years. When I
found this mailing list group, I started to think about going back into it.
But, I remembered that I never felt like I was finishing the bought casts
correctly-they looked okay-but not professional enough. So, I am asking my
questions based I what I remember when I was doing the work. I thought
that maybe jewelers use some kind of stripping process that I was not aware
of.
Thanks again for all your help,
Sincerely,
Marlene

Hi Marlene

Maybe I can help, but first I need to know the specifics.

What are the designs like? All curved surfaces, some flats etc…
What color gold and karat and your particular alloy/manufacturer?
New or scrap gold?
any micro-porosity in the castings?
Is your rouge buff contaminated?

Polishing is an art, and it takes years to get really good at it. A good
professional polisher can can do wonders for jewelry. In some shops the
polisher is the highest paid jewelry worker!

Handmade 18K and platinum gemstone jewelry. Fine die
and mold engraving. Diamond setting. Class rings/pins.
25 years experience in the jewelry trade. 515-469-6250

Marlene DeMers wrote:

Hi,
I would like to know if it is necessary to “strip” unfinished castings
first before polishing. If so, what process is used. If not, what is the
first step to finish the cast piece?

I have used rubber wheels first, then tripoli and then red rouge on 14kt
gold pieces, and they never look “bright” to me. What am I doing wrong?

Thanks for any help you can give me.
Sincerely,
Marlene

Marlene DeMers

orchid@ganoksin.com

procedures

orchid@ganoksin.com

Marlene DeMers

orchid@ganoksin.com

Marlene,
I can not see them of course so I have to try and advise you based on
the blind cybersurf principle of jewelry making advice so please
understand if I seem unable to pinpoint the problem.
It is possible that the castings were never right in the first place
if they all come from the same supplier.If a drop of strong nitric acid
fizzes on the item they are not 14 karat gold.I have seen fakes from
suppliers operating (in this case) out of Romania from about twenty
years ago that would fool even seasoned jewelry professionals and these
fakes were purchased in New York.I am not saying you have the fakes only
that there were alot from the area from about the time you describe. I
took a saw and cut one heavy pendant in half prior to melting it to cast
a ring for the owner.He lost $15,000 dollars to these scam artists.
Are they going to white or very light yellow when you polish and are
you using a flexshaft machine or a motorized method to polish or doing
it by hand…If you want to do the polishing by hand you will need emery
clothe(sand paper) in progressive grits to 2000 at least and work the
item with perhaps 1000 grit then 2000 then a clothe with tripoli and
then another clothe with rouge…This works but is slow and it takes a
little experimenting to know what grit of paper to use.
You could electro strip in cyanide solution but phoooey…To do this
you do the opposite of electroplate in other words hook the positive
wire to the work and the negative wire to a copper sheet to remove
copper or a silver sheet to remove silver.It is difficult to do properly
and if the cyanide solution fizzes you could end up with heart failure
or other serious medical problems not a pleasant thing this cyanide
stuff and a fume hood and rubber clothing and eyegoggles rubber gloves
and you have alot of hassle.Then to dispose of it when you are ready is
a problem and pouring it down your drain might get you 20 years in jail
now.A large quantity of hydrogen peroxide and chlorine will neutralize
the cyanide I am told but it takes about ten times the volume of the
original solution. There is also bombing which is boiling it in cyanide
and then dumping hydrogen peroxide into the stuff over a sink and
kawwoooosh your item is stripped or you’re dead which ever happens to
come first…Of course if you are a chemist and understand handling very
dangerous chemicals the above is within your ability…
Best in my opinion to get a hot plate(electric) a pyrex beaker and mix
a teaspoon of alum(spice rack in grocery) a teaspoon or two of saltpeter
(drugstores have it on the shelves) and a teaspoon or two of table
salt(non-iodized is best) in about half a quart of water and heat the
solution to almost boiling and drop the rings into this and add a little
water when necessary for a couple of hours…You will see small bubbles
on the surface of the object and it is from copper dissolving after the
copper is the silver and it will take a longer time to evacuate into
solution…This is relatively safe and has been around over a hundred
years…it does work to give a deeper higher karat color to fourteen or
ten karat gold… After it has boiled rinse and polish or you can polish
before the treatment…Hope this helps and if you can describe the
color or problem a bit more extensively and how you have gone about the
polishing process I may be able to get a better indication of what is
wrong…Gavin


#9

Marlene DeMers wrote:finishing not up to snuff.

one of the first steps in finishing a piece of gold jewelery (for
onesies and twosies is to bomb the piece or strip it). If you are mass
finishing, you will need to do a series of tumbling steps. From there
you can file all the rough areas , then emery , as much as you can. and
use small burrs to get into the tiny areas. you can also use polishing
sticks for the tough to reach areasyou will use a fine rubber wheel on
the inside of the shank, now it’s time to polish.use tripoli on the
entire surface, with brushes, stitched felt wheels. clean off all the
rouge. now you can bright polish with a good felt buffs and a good fine
grit bright polish.


#10

Hi Marlene

Possibly I can help shed a little light on standard polishing practices.
The routine I generally follow on rough castings is this:

(1) Finish the inside. If very rough I might use a half-round file.
Usually I’m able to use a cratex wheel followed by grey star (or tripoli
etc) on a felt finger. I might rouge the inside with a small buff on a
flex shaft for a superior finish.

(2) Use a sanding disk to remove sprue and generally straighten up the
casting, remove parting lines, etc

(3) Use a knife edge pumice wheel (Gesswein GK-90 is the best) on the
flex shaft to clean up some of the sanding marks where inaccessible to
buffs or laps.

(4) Use a small brush on the flex shaft to get around prongs, down
grooves and hard to reach places, polish inside the heads with end brush
etc.

(5) Use a highly polished tool steel round tapered-to-point burnisher to
clean up areas of the ring no brush or wheel can reach. A highly
polished miniature three cornered file (scraper) also works wonders.

(6) Use a 4", 5", or 6" properly dressed hard (usually flint or diamond
hard, and usually 1/2’ thick or so) felt lap (with tripoli etc) to
prepolish all the flat areas (sides mostly). Lapping is a dearly held
secret of most professional polishers, it can make or break a piece. One
of the tips for good lapping is to continually dress your lap with a
stone, keep it FLAT as possible, flat and smooth and true running. Cut
the backside at a 45 degree angle to an edge with the cutting side.
Lapping is a skill that develops over time and you’ll want to use a
light touch until you’ve got it down. Really good polishers sometimes
use a hard-rock maple lap to put a mirror finish on flats, especially on
platinum. Those guys are really good. I know polishers that use laps
made from all kinds of different materials, anything that works… You
can always cut a lap to whatever angle or curve you want too.

(7) Use a tripoli buff (I prefer treated muslin) to generally prepolish
without losing the edges created by the lap. Always polish parallel to
edges, never across edges. I try to pre-polish as dry as possible.

(8) Use a rouge buff with standard red rouge, Fabuluster, zam, etc, to
finish polish. I try to rouge as dry as possible.

(9) Clean in ultrasonic cleaner (I use the old standard, Mr. Clean and
ammonia, however many new and powerful cleaners are available)

(10) Clean and dry with a steamer if you have one, blast with air, or
dip in denatured alcohol etc.

tip: don’t over polish, don’t load up your buffs with compound unless
it works for you (doesn’t work for me)

tip: don’t polish away the edges, they give a crisp clean feel to the
piece.
Keep flats flat, rounds round, curves even, straight, clean, no waves…

These steps are very basic, there are very many variations according to
the ring design and material. A professional polisher’s workstation will
frequently have a board onto which are hung up to 10 variations of laps,
many different felt bobs, many different hardnesses and sizes of
brushes, several different buffs of each tripoli and rouge, finger
buffs, and who know what else…

I’ve really only touched on finishing here, it’s a vast subject, easily
worthy of its own book. hmmmmmm gives me an idea… :slight_smile:

         Jeffrey Everett

Handmade 18K, 22K, and platinum gemstone fine jewelry.
Diamond setting, rubber/metal molds, casting, lapidary
Die and mold engraving, plastic patterns for casting.
Cad jewelry design, cad/cam milling scroll filigree…
P O Box 2057 Fairfield IA 52556 515-469-6250


#11

I’ve really only touched on finishing here, it’s a vast subject, easily
worthy of its own book. hmmmmmm gives me an idea… :slight_smile:

Jeffrey: hey go for it on the book. Do you realize there AREN’T any books
on finishing? Not that I can find. MOstly articles just on the basics. In
my work I end up having to polish away most of the crispness because of
fire scale. So far I’m mostly working in sterling fabrication and when you
do 16 different soldering operations you’re gonna get firescale, no
avoiding it. Its why I’m getting more and more interested in working in
gold, I gather gold doesn’t have that problem to the same degree as
sterling. I’ve tried the Pripps and Cupronil but after many solderings it
doesn’t seem to make a big difference. But, YES, I for one would buy your
book on finishing. Another alternative is if you can buy or rent a quality
Beta video camera and know something about photography you could do a video
and sell those. There’s a guy who does that out of his home and you can
rent them from Ray Gabriel by mailorder and they are pretty bad mostly. One
of them he had a professional stone setter come by and show his working
procedures. The photography sucked but it was worth renting for the
and to watch a real pro make it look easy. Dave

Art Jewelry for Conscious People
http://www.opendoor.com/stephensdesign/crystalguy.html


#12

Gavin,

'Do ah Book, Do ah Book, Do ah Book!

In the mode of, “The Complete Metalsmith” by, Tim McCreight

Jim
At 12:39 AM 10/14/96 -0500, you wrote:

Jim Chambers wrote:

I assume that the piece is cleaned between trip and Red Rouge . . . never
the twain shall meet!

Jim

At 09:11 AM 10/11/96 -0800, you wrote:

Hi,
I would like to know if it is necessary to “strip” unfinished castings
first before polishing. If so, what process is used. If not, what is the
first step to finish the cast piece?

I have used rubber wheels first, then tripoli and then red rouge on 14kt
gold pieces, and they never look “bright” to me. What am I doing wrong?

Thanks for any help you can give me.
Sincerely,
Marlene

Marlene DeMers

orchid@ganoksin.com

procedures

orchid@ganoksin.com

procedures


#13

Jim Chambers wrote:

Gavin,

'Do ah Book, Do ah Book, Do ah Book!

In the mode of, “The Complete Metalsmith” by, Tim McCreight

Jim

Jim,
Have discussed this possibility with Dave and I think I am going to
do a series of smaller booklets on various phases of jewelry making.One
on soldering and one on casting and one on coloring and annealing and
pickling and so on.I would make them available seperately or together
with photos as a good part of each one.I have some experience on writing
how to type magazine articles and illustration with photos and feel this
is an approach that has not been covered well enough in the past…In
other words you could get one or more areas at a time.Sort of a lesson
at a time with how to go about it in photos and that way a person could
order them all or one at a time…as they progressed in any order they
wanted.I am not sure what a good printing would cost but I do know the
photos take quite a bit of time to set up and do in sequence and then
writing the text so yes I will do it but nothing definate about when the
first section will be ready.Perhaps by Christmas and let me know what
you think I should cover first…
and I will see if I can get it together…Gavin


#14

first section will be ready.Perhaps by Christmas and let me know what
you think I should cover first…
and I will see if I can get it together…Gavin

Gavin: let me know if I should dig out all those letters on this stuff you
sent long ago. Do you use Eudora? I wonder if you can read eudora Mac
files…hmmmmm Dave

Art Jewelry for Conscious People
http://www.opendoor.com/stephensdesign/crystalguy.html


#15

Dave Stephens wrote:

first section will be ready.Perhaps by Christmas and let me know what
you think I should cover first…
and I will see if I can get it together…Gavin

Gavin: let me know if I should dig out all those letters on this stuff you
sent long ago. Do you use Eudora? I wonder if you can read eudora Mac
files…hmmmmm Dave

Art Jewelry for Conscious People
http://www.opendoor.com/stephensdesign/crystalguy.html

orchid@ganoksin.com

Dave,
I am using Netscape mail which does alot of stuff Eudora doesn’t but I
have Eudora still on the machines.If you could convert to html
files…oh well could try sending a short one and see but I think
Netscape will handle it …Not sure I really need them now anyway…Gavin


#16

Gavin,

Judgeing by the interest in the forum . . No competition… It’s Castings
by Vacuum!

Jim

At 01:13 AM 10/18/96 -0500, you wrote: