Gold Solder Compositions

Hi all, I am trying to alloy a batch of 14k yellow gold easy and
hard solder. I and was wondering if anyone has an alloy formula
that works well. I purchased (many years ago) a couple of ounces
of solder alloys that worked well; but, it seems no one sells
just the alloys anymore - and I ran out. I do alot of my own
refining and have very little $$$ invested in my pure gold
(scraps and trade ins, etc.) and want to use some for making
solder with. I found this formula in a book and tried a small
batch. The problem was; it didnt flow at 1389F…It was closer to
1600F; which is about the same melting temp as my gold.

Au Ag Cu Zn MP
FP
58.3 18.0 12.0 11.7 1328
1389

58.3 20.8 19.0 1.9 1459
1526

The solder melted fine, but it seemed very “sticky” and wouldnt
flow well. Does anyone have any suggestions? Thanks in advance,
Ken Sanders

I am trying to alloy a batch of 14k yellow gold easy and
hard solder.

Hi Ken,

I also have had problems with solder being sticky and not
flowing nicely. These problems occured when we purchased some
cadmium-free solder. Refiners here (Germany) offer these solders
increasingly as dentists are not allowed to use any alloyed with
cadmium.

I found the following recipes in a book:

Au 585, Ag 104, Cu 241, Zn 70 hard

Au 585, Ag 104, Cu 241, Cd 70 hard

Au 585, Ag 81, Cu 219, Zn 24, Cd 94 easy

Unfortunately, no exact melting ranges were given. As you may
notice, these alloys contain much more copper than silver,
perhaps to provide for the discolouring by the cadmium, which
gives a slightly greenish tint to low-copper alloys.

Cadmium, however, is not good for your health, as are most
things you get into contact with in our trade. It is reported to
be toxic on inhaling its gases, resulting in bronchitis,
pneumonia, nasal cancer and other diseases of the respiratory
organs. Chronical intoxication damages the digestive system, as
any heavy metal, especially the kidneys. In animal testing it
was found to be carcinogen, gene-mutating and embryotoxic. I
don’t know what doses will result in these things, but at a
visit at a major refiner here, about 15 years ago, they said
that none of their melters reached pension age.

Another problem when alloying cadmium yourself is its very low
melting point. A lot of it goes up and away as gases in the
melting process, so you don’t know how much is in your alloy
actually.

I’d stay away from alloying my own solder, too much trouble
considering the amount I need. I rather pay a bit more.

Hope this is of any help, Markus