Soldering 18K White

I haven’t worked in 18K gold before.

I have the full compliment of solder for 10K and 14K white and
yellow, but I just got a beautiful pink sapphire ring to take down a
size. Can I substitute one of the solders I already have or do I need
to get 18K white solder? The chart I have shows the 18K solders
flowing at about the same temp? (Hardy repair book)

Thanks!
Barb Baur

would you want 10k or 14k solder in your 18k ring? Legally, as per
the patriot act, as long as the piece will still assay out within the
correct tolerances, youre clear. But couldt you charge 20 or 30 for
the job and buy a $12 piece of 18k solder?

my two cents - Zane
www.purcellgems.com

    I have the full compliment of solder for 10K and 14K white and
yellow, but I just got a beautiful pink sapphire ring to take down
a size. Can I substitute one of the solders I already have or do I
need to get 18K white solder? 

I would like to recommend 18, 19 or 20K white solders for sizing all
white gold rings. The 14K white gold solders are too soft and too
beige for sizing rings. The seams will show.

Bruce D. Holmgrain
http://www.goldwerx.com
@Red_Rodder
JA Certified Master Bench Jeweler / CAD/CAM Solutions

Hello Barb:

If you solder it with 14W then the “Solder Police” may show up at
your door and haul you off to the Jewelers prison lol.

In trade work it is usually best to use a solder of the same or even
higher karat. The important thing for you to note is that this 18K
item is most likely Rhodium plated and after you size it, it will
need to be re-plated. Do you have the proper plating set up? If not
you should pass on the job.

Michael R. Mathews, Sr.

I would use 18kt white easy, if necessary. You can always rhodium
plate the whole or part of the piece.

For good adhesion of Rhodium, one would be wise to electro activate
in caustic soda prior to plating. If you are going to use a lower
karat gold, you might find it necessary to plate.

Best wishes,
Robert Whiteside
www.robertwhiteside.com

         (...I haven't worked in 18K gold before...I have the full
compliment of solder for 10K and 14K white... Can I substitute one
of the solders I already have or do I need to get 18K white
solder? 

Dear Barb,

You will find that 18k alloys are much better to work with: Higher
melting points, and generally, less oxidization. Yellow and white,
even Nickel based alloys, are more friendly for fabrication and, as
you need, sizing. Regarding your question, before saying that you
could use either one of the solders you have available, you must
consider the following points:

  • Do you know, or could guess what kind of 18k white alloy the ring
    was made with, I mean Nickel or Palladium based?

  • Is the ring going to be Rhodium plated after sizing, or is it
    already Rhodium plated?

  • A different white tone at the soldering area would be a problem?

  • Does the ring has a strong enough sizing area to compensate the
    weakness of a lower karat soldering?

Ideally, you should use a 750/1000 solder that has the same base
alloy (Nickel or Palladium) in order get the best joint strength,
closest color and preserving the title integrity of the piece - 18k.

But since we are talking about a repair, you may have room for some
flexibility…it means that you can use either one of the solders
you have, but I would suggest that you use the highest karat - 14k.
If you are going to Rhodium plate, the difference in color will be
hidden by the plating. Anyways, most of the “repair” solders
available, even the ones indicated for 18k alloys, are actually, low
carat solders, i.e. , 14k or so.

No matter what you decide to do, remember to protect the piece to be
sized with a coat of a saturated solution of Methyl Alcohol and Boric
Acid, specially if the piece has already a Rhodium plating. It also
helps to protect the Sapphire.

Good Luck!
Christo Kiffer
Colorado Springs, CO

Most solder manufacturers & suppliers offer both plumb gold solder
(full karat) and repair gold solders (under karat). The plumb solders
should be used for any and all manufacturing, before the finished
product is sold to the retail customer, to maintain the required gold
fineness as specified in the National Gold & Silver Marking Act. A
repair solder is often used for sizing and repairs to a piece that
has been purchased and worn by the end customer. While Stuller does
not endorse using a lower karat solder for general repair, it is a
very common practice, as the jeweler saves money by using a repair
solder of lower karat, designed to be the same color as the piece
being soldered. Many repair solders also offer the advantage of
flowing at a lower temperature than plumb solders, reducing the
chance of accidentally remelting solder used to manufacture the
piece. Stuller carries a full array of both cadmium-free and cadmium
bearing repair solders. Let me know if I can help.

James Gilbert
Stuller Metals
800-877-7777 ext 6113