Accidently deleted an email before responding. A reader was concerned about a description of casting methods. They referred to the lost wax method which is not used commercially today. What is used is sand casting. This consist of packing sand around a wooden model (sand contained in frame), then removing the model and pouring grey iron etc.into it. Just watched a YouTube video to refresh my memory. I have done quality audits at several foundries. Now back to writing.