Large Cauliflower Cancers on Castings


Four  in five castings have large cauliflower cancers. Some are open and some are closed. Investment is inside. They look like the investment broke away in the mold.  I have been casting for two years without a problem. Now this is happening all the time.  I use a Neycraft centrifuge wound 2 ½ turns. Three 4X3 flasks in kiln. I use Kerr Satin Cast. After investing, flasks are undisturbed for three hours then sealed in bags to keep moist for burnout next day. Burnout kiln is computer controlled, 300 1hr, 700 2hr, 900 2hr, 1350 2hr, 950 1hr, cast. I use an Oxy/Acetylene torch to melt silver. I remove flask from kiln and melt silver in less than one minute. I am extremely careful not to hit or shock the flask in any way. Silver is always new casting grain or cut sheet silver. Two castings are in each flask. Castings are 1/16” – 3/32” thick, 1 1/2" wide and 3" tall.  Sometimes one will be perfect and the other is trash. Most of the time both are trash. Any help out there? Have photos, but can’t bring into message.  Joe


johndach's picture

castings have large cauliflower cancers

If things have worked well for a number of years and all of a sudden this is happening, what have you changed. If you haven't changed anything that you are aware of, Cynthia (my wife and LOOONNNG time jeweler/caster) feels it is likely some sort of turbulence shearing investment, or there is moisture in the investment, lumps in the investment causing a weak spot, (if different wax) wax could expand before melting and crack off investment, etc. Something has been changed somewhere...... Could be a "new batch" of wax, investment or ?? of the same brand as before but there is a problem with this particular batch of product. This sort of problem is hair pulling for sure. Can only suggest that you start eliminating/changing one thing at a time to see if you can get this problem to stop.

Good luck. Also a picture would help.......

John Dach
john@MLCE.net
360.681.4240
web site: http://www.MLCE.net and ctmandalas.com