Our club is recently reviving lost wax casting. Equipment has been upgraded and beginning classes are underway. I have several questions owing to our recent experience.
1 - A fair number of beginning projects are having issues with filling the cavity completely. The project was a single pre-cast wax ring in a single small casting flask - not multiples on a tree. Basic cylindrical rings casted well. Signet-style rings all had serious issues.
While there were no issues during fabrication using the pre-cast rings (we just added sprues), a key blame is being placed on the wax as being “old”.
While the variety of wax material (rings and sprues) are up to 10 - 20 years at most, all are pliable, melt well, and do not crack. (e.g., has not melted or has not crystalized). The fix is proposed as throw out all wax and buy a complete new supply. As the ‘old’ wax has not been tested against new wax, I’m anxious about this as the sole issue.
Can others point to issues with old wax that we should be aware of?
2 - I suspect a key issue is improper or inadequate spruing. (We’re all beginners.) Can folks suggest an excellent book or two that give practical information on spruing for different scenarios?
Many thanks to everyone!