Ganoksin was of great help for me in the last couple of years. It’s
one of the best resources of the web and certainly it’s members are
I have a ring which gives me a big headache lately and would be
really happy if somebody can give me some pointers
This is the (poor) casting result in white gold:
Now, the facts:
18k White Gold (12.5% Palladium/ 12.5% Silver)
Kerr SatinCast 20 (5 hour burnout cycle as recommend by Kerr)
Flask Temperature at casting 650C
Centrifugal Casting (with oxigen/propane torch)
As you can see in the photo there are holes in the bottom half part
of the ring and the casting did not fill up correctly. Sprue has
holes as well. The upper half is completely smooth as it should be.
My modifications for the next casting cycle are shorter and thicker
sprue and increase of the centrifugal casting speed. I am guessing
that the material cooled down to quickly resulting in the holes.
Now, after researching the web, the other reason for the holes could
be gas porosity and/or the reaction with the investment…
As you can see, I am a bit in the dark here. If somebody had some
similar issues or has some ideas, I would be grateful.
PS: If this has been discussed “to death” or it is not the correct
way to ask in this mailgroup, I apologize