Vaccum castings and Fire scales/ deox

Alma, you mention that you have a large quanity of deox silver. I am
using antifirescale casting grain with my centrifugal caster. I’m
wondering if this is the same as deox sterling. I buy it from Rio. I
do not wait 20 minutes after casting because I don’t like to take
the time to dig the item out of the investment. When I quench it hot
it boils away and the silver drops out easily. I have no problems
with brittle castings. I’ve been assuming it antifirescale casting
grain is the same as deox sterling. Does anyone know if this is true?

Hi Annette and others… First, I would like to mention that there
are now many types of De ox silvers and anti-firescale silvers on the
market. Many of these have different alloys and different
properties… what works well with one type of alloy, may not be
correct for the next one… so, the best thing to do is to speak with
your alloy manufacturer and get all the pertinent info on the
material you use. Personally, I buy all my alloy’s from United
Precious metals as they are the original inventors of the material
and hold the patent rights . They also know a lot more about the
properties of the material than anyone else and are very helpful
when you have a casting problem related to the alloys they make.
There are a lot of knockoff alloys that are copies of their’s that
have had certain properties left out to attempt to by-pass their
patent… as a result, some of the copies do not have the
reusability of Uniteds metal.

The general rule of thumb when quenching Deox metals is to wait 20
minutes for a standard flask that is approx 4" dia by 6 or 7 " tall.
If your flasks are smaller, then it is possible to quench sooner…
for example , a 3" by 4" flask will be ready in about 10 minutes as
these flasks cool down quickly by themselves. Now, some items like
pendants and earrings will not show anykind of problem that you will
notice if you quench quicker… However, if you are doing rings with
deox and you quench too soon, the metal will be “hardened” and will
be easy to crack when attempting to size the ring through
conventional stretching methods. In some cases, if quenched to soon,
the shanks will crack or the ring may be brittle…This is not
apparent with items that are not rings.

We cast about 30 flasks a day in deox sterling and have never had a
problem with cracking or brittle metal. If the flasks are cast way
too hot, brittle castings can also occur and other problems will be
apparent. Daniel Grandi

We do casting, finishing and a lot of other processes for designers
and people in the trade.

United Precious metals are the original inventors of the material
and hold the patent rights . 

G’day Daniel - a small point perhaps, but Tony Eccles of APECS
Investment Casting in Melbourne Australia is the bloke who developed
these alloys 30 years ago - Tony holds the patents and it’s my
understanding that U.P.M.R. operate under license from APECS.

There is useful technical about these alloys heRe:

as well as some historical stuff.


Allan Heywood

Hi Allan, You may be correct about the first versions of this type of
silver… however, UPM has done a lot of research and developed many
other alloys beyond the first versions which actually work much
better, are harder, and have less problems in production… I do
believe they hold the patents on these … In anycase, that is what
I have been told by them.

I started using the original alloy when it first came onto the
market when I was manufacturing Items for Tiffany … then I tried
each new alloy as it became available and noticed a lot of
improvement… I have also tried other brands and found them to not
have the same reusability that the newer alloys from UPM have. These
are just my observations… usual disclaimers …

Best Wishes,

    I've been assuming it antifirescale casting grain is the same
as deox sterling. Does anyone know if this is true? Annette 

hi annette, I’ve tried deox silver from a different source to my
casters supply, and the results ( when cast by the same casters
using the same method) were quite different. there are different
additions to different companies “deox” “anti firescale” “bright” or
whatever they are calling it, Christine