Did my first 14kt white gold casting yesterday and had some
questions for the pros that will help other newbies as well as
myself.
I’m using perforated flask 2.5 inch by 4 inch in a VIC 12 and
electro melt furnace. I placed the flask in the well, hit the switch
and took maybe two seconds to hit 25 pounds on the pressure gauge and
I poured.
Normally I do 14kt and Argentium at 1,810F for pouring the metal and
1,050F for the flask that has cooled to that at least an hour. That
works fine as a general rule, increasing a little or decreasing a
little for heavy or fine pieces.
For the white gold I used a pour temperature of 1,945F and 1,125F
for the flask. When I poured the metal seemed to gob up into a big
round blob and left two round blobs in the crucible. I chalked it off
to a bad try and thought I should increase the pour temp by 50
degrees. I let it cool 17 minutes and grabbed the spaghetti colander
to catch the glob after plunging.
(the wife was not home so she would not know!) To my surprise the
casting came out. It was a single wedding ring, size 8 and about 8
grams. The metal did not pool and swim like I am accustomed so I
expected a failed cast. I had a few surface pits that have almost
polished out. Not sure what caused those.
So, should the metal be hotter? Should the flask be hotter? Should
the button be flat on the top as it is with the 14kt and silver? The
metal was Rio’s 14kt white from Canada and is polishing at a very
bright white. They recommend a pour temp of 1,886F but I know there
is a variance in the furnaces. I didn’t want to try 100 degrees over
on my first shot.
I’ll be trying rose gold next.
Thank you for suggestions.
Charlie