Problems casting Argedent 62

[Dougie]

I have been casting for a large lab for over 20 years on an ECM4 Austenal casting machine. We have been using Argedent 62 for longer than that. Around 5 years ago, we started noticing foreign objects in our buttons and sprues after casting. These objects are not investment. They are hard and grey. I have to dig most out with a carbide burr. They are so hard that they can dull a new burr. Sometimes they travel into the casting themselves. We cast seven other precious alloys and 4 non prec., and we do not have this problem with any other alloy. The alloy manufacturer told us that it was from using an induction casting machine. Others told us that it was from using a carbon insert. So my boss had me stop using the ECM. I started with new metal and have been torch casting for the last week, and guess what, the stuff is back. Anyone have any ideas.
Thanks,
Dougie

 

[sixonice]

I would immediately send a sample of this substance in the alloy right to Argen ASAP. They have the technology and equipment to run specific tests on the alloy and give you back the information you asked them to help you with the first time around. Frankly, it's their alloy and you sound like a good customer of theirs, so I feel they should step up and run some analysis for you - at least tell you what that material is. It's easy for them to blame your casting machine, but now with you hand casting and the problem returning, it's a problem they should help you with. Just my opinion.......

 

[Dougie]

We did, thats the problem. They have been pulling our chain for years. We even paid for their master tech. to fly to our lab and show us the "Proper" way to cast their metal with a torch. Their most recent "analysis" is that it must be the investment. Their is something that they are not telling us. I have personally done over 100,000 castings with this metal alone. Something is different with it now. The fact is, either they don't know, or they don't want to fess up to what the problem is. We are very frustrated with them.