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Platinum casting defects are often very difficult to characterize due to the intrinsic complexity of the investment casting process. All defects will fall into one or more of the established seven categories of casting defects. The proper identification of a particular defect is the prerequisite to correcting and controlling the quality of platinum castings. It is contended that a system of defect identification should be based solely upon morphological criteria with no prior assumptions relating to the cause of the defect. The nature of a casting defect can only be determined by correctly categorizing the shape, appearance, location and dimensions of the defect. The importance of a controlled and comprehensive defect analysis program is advanced. Once appropriately classified, the possible causes can be examined and the corrective action can be taken..... (2005) Complete Story
Manufacturer spend much time and money diagnosing defects that are believed to originate in the casting process, but actually occur during waxing. Many companies run in circles, changing this gate/sprue, that metal, these temperatures, and screaming at suppliers to try to fix the 'mystery' problem. While these areas certainly can be the source of problems, many defects are misdiagnosed as casting defects, and thousands, perhaps millions, of dollars are wasted in search of non-existent flaws in the casting process.... (2003) Complete Story
A good practice for preventing investment blowout is to measure the height of the trees before investing. The maximum tree height should be between 0.5 inch and (for larger trees with more metal) 0.75 inch shorter than the fill level of the flask. It's also important to leave a 0.125 inch gap between the top of the investment and the top of the flask if you are using benchtop vacuum casting with a solid flask.... (2003) Complete Story
As many jewelry manufacturers and goldsmiths know from hard experience, cracking in jewelry can occur at any time during its manufacture. It can also occur much later, after the jewelry has been sold to the consumer or during repair. Cracking can also occur in the processing of the starting materials (the casting grain and mill products from which the jewelry is to be made), and may not be detected until several stages later in the manufacturing process....This article discusses these causes as they relate to cracking and the steps that can be taken to minimize their occurrence. The particular focus is on karat golds, but much is also applicable to silver and platinum jewelry.... (2003) Complete Story
