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Using Bi-metal


#1

There are two widely used precious bi-metals on the market today, as
far as I know. One is 1/20th 18k gold over sterling. This is a
material I developed and had manufactured for me in the mid 1980s
and then threw open to the field. It is made by Stern -Leach in
Attleboro, MA. and is still made to my original instructions. They
have large minimum orders so it is now distributed in smaller
quantities by Hauser and Miller in St. Louis. I don’t get a
commission or anything on this, which is fine with me. The material
is a recipe variation on gold filled (which is usually 1/20th 14k
over brass or other base metals). These proportions are by weight.
Since gold is heavier than silver the layer of the gold is therefore
less than 1/20 of the silver in thickness. How much less I will
leave to those of you inclined to do the math. It was most likely
manufactured by others before I reintroduced to our field. When I
was first trying to find someone to make it, I was told that they
did something like this during the copper shortages of World War II.

The other product is 1/8 22k gold over silver (I think it is
sterling but it might be fine silver). I assume this is also by
weight, since that is standard industry practice. The layer of gold
is much heavier in this product. As a result it is more expensive.
With that expense comes the beautiful color of that 22k and added
thickness of gold. This is made by Philip Baldwin, from the Seattle
area, for Reactive Metals.

Both products can be roller printed, soldered with a little care and
used for wide applications. Good stuff at a good price. On mine I
avoid hard silver solder and usually start with medium. Most of my
application is sweat soldered so the color is not to much of a
concern. I always use something to prevent fire scale (usually Prips
flux) since if you get blush in this gold you won’t be able to sand
it off. Since it is a thin layer, any abrasion should be limited. I
usually roller print textures on it and brass brush finish it.

Both products are also much heavier on the gold that any traditional
plating would be. They hold up very well.

In terms of stamping, my impression is that they should be stamped
1/20 18k/sterling and 1/8 22k/sterling. That said I have always
stamped my production line 18k and sterling. If you want to get
technical, you could do what some of the users have done and have a
special stamp made. Whether you do or not may depend on where and
how you market your work. In the JCK world, I would have the stamp
made, in the craft shows where I show, it doesn’t seem necessary to
me.

two cents worth,

Don Friedlich


#2

Don, You can’t use the sterling stamp with the 1/20 18k stamp on the
same piece. The Stamping Act states "It is unfair or deceptive to
mark, describe, or otherwise represent all or part of an industry
product as “silver,” “solid silver,” “Sterling Silver,” "Sterling,“
or the abbreviation “Ster.” unless it is at least 925/1,000ths pure
silver.” so because you have laminated 50 parts per thousand 18k
gold onto the sterling it will assay out as somewhere between 875
and 887 parts per thousand silver depending on how much silver is in
the 18K alloy.

This is one of those things where smiths say "gee you should be

able to do this because I am not deceiving anyone, in fact I am
giving them something more valuable" but the reality is the law does
not take this into consideration. As I have said before about this
it is unlikely you will ever be sued over this but you are still not
supposed to use more than one quality mark on a piece. Here are the
relevant paragraphs from the FTC

=A7 23.4 Misrepresentation as to gold content. © (3) An industry
product or part thereof on which there has been affixed on all
significant surfaces by soldering, brazing, welding, or other
mechanical means, a plating of gold alloy of not less than 10 karat
fineness and of substantial thickness5 may be marked or described as
"Gold Filled," “Gold Overlay,” "Rolled Gold Plate"or an adequate
abbreviation, when such plating constitutes at least 1/20th of the
weight of the metal in the entire article and when the term is
immediately preceded by a designation of the karat fineness of the
plating which is of equal conspicuousness as the term used (for
example, “14 Karat Gold Filled,” “14 Kt. Gold Filled,” “14 Kt.
G.F.,” “14 Kt. Gold Overlay,” or “14K. R.G.P.”). When conforming to
all such requirements except the specified minimum of 1/20th of the
weight of the metal in the entire article, the terms "Gold Overlay"
and “Rolled Gold Plate” may be used when the karat fineness
designation is immediately preceded by a fraction accurately
disclosing the portion of the weight of the metal in the entire
article accounted for by the plating, and when such fraction is of
equal conspicuousness as the term used (for example, “1/40th 12 Kt.
Rolled Gold Plate” or “1/40 12 Kt. R.G.P.”).

=A7 23.6 Misrepresentation as to silver content.

(a) It is unfair or deceptive to misrepresent that an industry
product contains silver, or to misrepresent an industry product as
having a silver content, plating, electroplating, or coating.

(b) It is unfair or deceptive to mark, describe, or otherwise
represent all or part of an industry product as “silver,” “solid
silver,” “Sterling Silver,” “Sterling,” or the abbreviation "Ster."
unless it is at least 925/1,000ths pure silver.

© It is unfair or deceptive to mark, describe, or otherwise
represent all or part of an industry product as “coin” or “coin
silver” unless it is at least 900/1,000ths pure silver.

(d) It is unfair or deceptive to mark, describe, or otherwise
represent all or part of an industry product as being plated or
coated with silver unless all significant surfaces of the product or
part contain a plating or coating of silver that is of substantial
thickness.8

(e) The provisions of this section relating to markings and
descriptions of industry products and parts thereof are subject to
the applicable tolerances of the National Stamping Act or any
amendment thereof.9

Jim


#3

I have been watching this discussion with interest. RMS does carry a
"1/8 22KGF" stamp for our Bi-metal product. It is straight shafted
with 1mm letters. Bill


#4
    I have been watching this discussion with interest. RMS does
carry a "1/8 22KGF" stamp for our Bi-metal product. It is straight
shafted with 1mm letters. Bill 

Bill, Your stamp is the correct way to mark your bi-metal. The
Hauser & Miller material could be stamped 1/20 18KGF .

Jim
James Binnion Metal Arts


#5
  I have been watching this discussion with interest. RMS does
carry a "1/8 22KGF" stamp for our Bi-metal product. It is straight
shafted with 1mm letters. Bill 

Thank you for jumping in on this, Bill! Why did you wait so long
:-)? I knew there was a proper way to stamp bi-metal as gold fill
but couldn’t remember what it was. Thanks for clarifying.

Beth