As we all know casting white gold is a little trickier than casting
your standard yellow gold. Ideally I like to have a little extra for
a nice button and solid flow. When casting 14 kt. white gold scrap
that has been. cast a few times already the chances of porosity and
other issues are greatly increased. Does anyone have any suggestions
that will help limit this type of issue? I like to stick to the
alloy manufactures suggested casting temperature’s but have not had
the best luck. It’s always nice to see a well rounded button with no
crazy splashing, and sharp edges, but it seems once you loose some
of the elements of the alloy in the first couple casts this is
extremely hard to accomplish. Any alloy, or technique suggestions
would be greatly appreciated.
Any alloy, or technique suggestions would be greatly appreciated.
Considering the fuss and bother and aggrevation you go through when
a casting turns out crappy, why not just send the scrap to any decent
refiner, asking to get the appropriate new casting grain in return.
Find one of the refiners that does not charge a set lot refining fee,
such as David Fell. They pay in the mid 90 percentages for the gold
content, then of course charge you a bit over the spot price for the
new alloy. But I think you’ll find that the added cost of not using
all scrap will be quickly paid back in the better castings. Remember
that you usually can use a mix of old CLEAN scrap and new metal with
equally good results. Just be sure the old metal is metal without
inclusions, solder, etc, which itself produced decent castings the
last time it was cast. That way, you buy new metal as needed, mixing
the new with the old buttons and sprues, and don’t end up with only
old messed up metal.
You’re right about white golds being fussier. In my experience,
attempts to revive significantly junked up white gold scrap end up in
failure more often than not. Once it’s casting into porous or overly
hard, cracky, brittle or otherwise unacceptable castings, it’s better
to scrap it out and save yourself the trouble of trying to rescue it,
since those efforts generally don’t work so well. The percentage paid
by refiners for the gold content when what you’re sending is clean
scrap for which you only wish to be paid for gold content, rather
than mixed precious metals, is high enough that simply scrapping the
unacceptable metal is much more cost effective.
It definitely wouldn’t hurt to mix some good metal with what you
have if its origin or number of times cast is in question. Make sure
your wax has plenty of feeder sprues to speed up the metal getting to
the bottom side. I will also make sure flask temperature isn’t too
low.
I once had an issue with re-casting white gold. Luckily it was an
ordered wax and not hand carved. After several attempts, I finally
decided the customer’s gold was no good. You should be able to tell
when it starts to flow in the crucible. If it seems like it takes too
long to become fluid, put the flask back in the oven and rethink your
strategy. Nothing like a casting that looks like swiss cheese.
