Paul Woods wrote:
I am greatly insulted by your tone and it appears that you have not put any thought into your comment. Seriously?
Yes, I was blunt. Not any thought? How's your tone yourself?
You are trying to tell us that ALL the metal in a casting cools to freezing point at exactly the same moment?
No, I didn't, nor does it matter.
the metal might eventually shrink equally, but not all at the same time because cooling happens from the outside in, and this can be used to our advantage.
Ah, you do know that it shrinks equally. This discussion began with the question of how much lost-wax patterns are made oversize to account for this shrinkage. It most certainly IS the entire shrinkage that is relevant to this topic.
....as a metallurgist you should be aware of the high density of metals such as steel and brass, and thus the pressure that will be exerted that can keep pushing semi-molten metal down towards the bottom of a mould when it is cooled slowly enough
Mold filling is NOT the issue: important, of course, but not the issue here. So on this point, what you say is entirely true, but irrelevant.