Raising Karat of 10k gold alloys

1st - Does anyone have a spreadsheet that will do alloying
conversions? I thought it wouldn’t be too hard to create one from the
chart in Tim McCreight’s book, but why reinvent the wheel?

2nd - 10k rings & such are pretty easy to come by from our local pawn
shops/metal detectorists, but I’d prefer to work in 14k or 18k. Has
anyone alloyed standard 10k up to 14k or 18k? How’s the color &
workability? I cast, but I’d like to have an alloy that I could roll
in my mill as well. Thoughts? Should I order 24k, or 22k casting
grain to work with?

Diane & Charles Hofmeister

As for raising the karat of your materials:

I purchase 24kt., or .999Ag casting grain exclusively. From those
two one can make anything your jewelry requires- from wire and tubing
to sheet or plate and in any karat or colour desired. Various master
alloys can be purchased as well that have deoxidants, etc. blended
into the compounds (if you like to use them, or) for a consistent
base colour throughout your mill work ( as the quantity of 24kt
decreases the colour becomes more pale or “european” in
hue/saturation) or properties that a specific manufacturer’s formula
adds to a pour that may suit a variety of your needs. For me it
makes the most economic sense not to mention the versatility and
range 24 Kt. provides.I never have to worry about running out of
anything nor having materials for experimental pieces or experimental
alloys! I always recommend my students become proficient in alloying
their own metals too. In fact A copy of Harold O’Connor’s “Jewelers
Bench Reference” is a standard in their toolkit for the wealth of
alloy formulas and fabrication equations so that with a rolling mill
one is ready for anything you can conceptualize! One note Re: the use
of 9kt-10 kt : keep in mind materials that were added to alloy the
gold the first time round- Some have metal you may not want that can
toughen your ingots to an almost un-malleable degree ( brass for
instance). A small test pour is better than finding out your entire
batch had ferrous metals in it.

A small test pour is better than finding out your entire batch had
ferrous metals in it. 

Ferrous metal has iron, and no alloys are made for gold containing
iron. Non-ferrous metals include gold, silver, brass, aluminum, lead.
Any metal without iron.

Richard Hart G.G.
Jewelers Gallery

I agree with the fact of starting with pure metals. The best alloy’s
are made by using "known"pure as possible metals. Why should one mix
9 or 10 karat gold with pure precious metal in order to become a
higher karat alloy of unknown purity and consistence?

If been in there, don that, had the same thoughts of raising low
karat gold, but on the if you take al the effort and materials in
account, then you realize that you are losing time and money in this
lower karat range. For this reason, I just collect this gold and have
it refined. Yes I have to pay for it but I’m 100 procent sure of
starting with clean metals, serving my customers with the best
quality possible for my standards.

However, for those fellow jewellers who are in the position of
raising the lower karat gold to higher, having all the materials
(acids, mixture powder, crucibles and others), time and knowledge,
please go a head and have fun. I like to go with simple and straight
forward metals which allows me to end up with a consistent color and
no “what in the hell is wrong with this stuf” moments.

Best regards and keep the standards high -)


Hello Diane and Charles,

1st: Oppi Untracht’s Jewelry concepts and technology has spread
sheets for conversions.

2nd: To raise the karat of gold:

FG = S ( KW _ KS ) / 24 " KW

FG =fine gold
KS = karat of the scrap metal
KW = the karat we want
S = weight of the scrap metal

example: We have 20 gr. 10. We want to raise to 14 K. How much fine
gold we need? FG= 20 (14-10) / 24-14 = 20 (4) / 10 = 80 / 10 = 8
When we add 8 gr fine gold to 20gr 10 K gold we get 28 gr 14 K.

Kind regards,
Oya B