Oilsand is actually still used - probably it's a little better than engine oil and cement of course! and sometimes builder's lime is used in the making of furnaces amongst other stuff like fireclay, refractory cement and sand.(and yes, ordinary Portland cement is known to have been used as well!).
I think that a lot of different mixtures could be used (especially in the making of cores) from molasses, to flour, to cow dung! Then some moulds are made with plaster of paris and silica sand. Greensand for moulds is made with a little bit of fireclay and water. (yes water Frits).
Flettner makes his moulds from sand mixed with silica gel and hardened by passing Co2 through it, making it a very good mould which stays together when moved around - he gets some great results.
Ken is also into casting pistons amongst other things.
However, it's not a very precise process really, a bit like being a baker with all the ingredients in your head and the ability to know how much of what to use without a book! - In fact, desigining a burner is a bit like building and tuning a Bucket engine, except that you can't take it for a test ride!
Bookmarks